2012 Journal

----------------------------------

taga 2012

jacksonville ----------------------------------

---------------------------------california polytechnic state university san luis obispo

vol. 1 -----------variability of electroluminescent displays -----------by C. michael shedd + nathan ostrout

vol. 1 -----------variability of electroluminescent displays -----------by C. michael shedd + nathan ostrout

taga 2012

jacksonville ---------------------------------

--------------------------------california polytechnic state university san luis obispo

Copyright Š 2012 by California Polytechnic State University, San Luis Obispo Technical Association of the Graphic Arts, Student Chapter All rights reserved. All material in this book has been compiled with the knowledge and prior consent of those concerned, but is published without responsibility for errors or omissions. Nothing in this publication shall be reproduced without the express written consent of the authors and editors. Every effort has been made to ensure that credits accurately comply with information supplied. We apologize for any inaccuracies that may have occured.

First published in the United States of America by: Cal Poly TAGA Student Chapter One Grand Avenue San Luis Obispo, CA 93407 Printed at California Polytechnic State University, San Luis Obispo

Either write something worth reading or do something worth writing ------------Benjamin Franklin

vol. 1

variability of electroluminescent displays -----------by C. michael shedd + nathan ostrout

Introduction Consumer product companies are demanding new and innovative print solutions to increase sales and compete with the vast amount of advertisements pleading for the attention of consumers. Electroluminescent (EL) printing is one solution to this growing demand for more effective marketing collateral.

Electroluminescent displays create a kinetic visual element by lighting up.

These displays are useful in such instances where brightness, high contrast and a wide angle of view are required. Electroluminescent printing combines the features of both traditional graphic printing and EL inks for the production of commercial prints, products, and packaging that illuminate (Hart, 2010).

EL displays, by a large part, are produced by screen printing several layers of functional inks. While screen printing has traditionally been used for graphic imaging processes, awareness of the process’ functional printing uses has introduced it to the EL printing segment. Screen printing, currently the optimal print choice for EL displays, have many variables, which arise from the nature of this process, both which promote and inhibit the performance of functional ink layers. The effects that these variables have on printing EL displays will need to be analyzed to make constructive improvements for all applications.

This study asks: how does the screen printing variables affect efficiency of electroluminescent displays? Based on previous studies and research, traditional screen printing methods are adequate for obtaining desired results for different functional layers in electroluminescent displays . Squeegee pressure, printing speed, emulsion thickness, and screen mesh count are all variables that are involved in screen printing and need to be quantified in order to determine optimal operational conditions. Furthermore, printed functional ink film variables need to be examined for their effect on the display. These variables include surface uniformity, thickness, and printing processes (e.g. wet ink on wet ink or wet ink on dry ink). In order to understand optimal

printing characteristics for efficient current conduction and illumination of a display, this study attempted to control human errors during operation that might lead to additional printing related variables. As a result, an automated screen printer was used. The enhancements of the screen printing processes were key for printing fine detail work and in the end aided to the success of printing electroluminescent displays.

The purpose of this study was to optimize the screen printing process pertaining to the printing of electroluminescent displays. Printed electronics is a fairly new concept in the graphic communication industry and to date has only been employed by a limited number of professionals. Therefore, this research study was conducted to identify optimal processes for screen printing electroluminescent displays. The research was intended to help understand how printed electronics could be printed with conventional screen printing.

Literature Review There are two main categories of emitted light, consisting of incandescence and luminescence. Incandescent light is produced by an electric current, which passes through a filament, the transmission of which generates heat and in turn emits light. Luminescence is thereafter defined as any radiant energy that is not generated by a change in temperature and encompasses electroluminescence, and is the focus of this study (Hart, 2010).

Electroluminescent displays require a minimal amount of energy compared to other forms of light. These displays which are composed of a series of functional layers, undergo several steps in order to generate light. Electrons are tunneled from an electronic state at the phosphor interface until they are ultimately accelerated to high levels by fields in the phosphor. These highly energized electrons then activate the luminescent region of the phosphor. Once this region returns to a ground state it emits the basic unit of light, a photon (Hart, 2010).

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A record of the electroluminescent phenomenon dates back to the early 1900s.

Henry J. Round conducted the first recorded study of electroluminescent in 1907. Round, an American scientist who at the time was analyzing radio waves, observed a discharge of various hues of light while transmitting a current through silicon carbide (SiC). However, research on the technology remained relatively quiet until in 1923, a Russian experimenter by the name of Oleg Lossev made a similar observation to that of Round while also conducting fieldwork on radio waves. Lossev would later make a significant contribution to the field of electroluminescent by publishing detailed documentation on his findings in 1940. Concurrently as Lossev was performing his research, French engineer Georges Destriau discovered that zinc sulphide (ZnS) was capable of emitting light under conduction. In 1959, the Westinghouse Company produced the first zinc sulphide electroluminescent panel in America as part of their research and development and would eventually lay the foundation for commercial production of electroluminescent displays. Today, electroluminescent displays have found a market in commercial prints, products, and packaging and are primarily produced by methods of screen printing (Peaker, 1970).

For many years, only those who were exceptionally skilled at screen printing could print superior results for electroluminescent displays. However, R. J. Horwood (1974), screen printing researcher focused in ink film thickness, explains, “in recent years, a more scientific approach to the age-old craft of screen printing has resulted in the evolution of complex precision-built printing machines for use in the electronics micro-circuit industry” (p.129).

As print technology keeps growing, the call for specialized print processes does as well. As a result, due to screen printing’s capabilities, the process appears to be the most optimal form of production for printed electronics (Horwood, 1974).

Screen printing is a process by which ink is pushed through a polyester screen stencil and onto a substrate (Hensen, 2007). The image (C in Figure 1) is

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printed onto a transparency, which is used to image a polyester screen, mounted into a frame (D in Figure 1) and coated with a photosensitive emulsion layer.

The transparency is secured on the screen and then exposed with ultraviolet light to cure the emulsion. The uncured portion of is then removed by water, leaving openings in the screen for printing. Screen printing ink (A in Figure 1) is then placed onto the screen and a squeegee (B inFigure 1) is used to force the ink through the stencil. There are certain types of squeegees that can be used, each having a unique affect on how the ink is transferred through the stencil. The image can be printed onto numerous types of substrates (E in Figure 1) including paper, fabrics plastics, and metals (Hensen, 2007).

Figure 1: The Screen Printing Process

Traditional screen printing techniques do not require extremely tight process controls over each variable of the printing process. However, the printing of functional inks need careful monitoring to ensure accurate print results.

Printed electronics depend on specific characteristic values to function, which influence resistivity (Horwood, 1974). Therefore, it is important to maintain control during the printing process to ensure electroluminescent displays function effectively.

It is also important to understand the qualities of screen printing inks and how they are comparable to that of electroluminescent inks. The important aspect of screen printing inks is the is their viscosity, and how ink’s resistance to flow plays a part in the screen printing process. Horwood explained that

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screen printing inks, “exhibit a kind of quality that when at rest are extremely viscous but flow quite readily under moderate shearing stress, a force that is applied parallel or tangential to the face of the material, which are termed pseudo-plastic” (Horwood, 1974). The purpose of such qualities is to ensure that the inks do not flow after they are printed so that the image does not acquire any dot gain (Horwood, 1974). Screen printing inks have a high viscosity making them very rigid and able to hold their form.

The pillar theory presented by Horwood (1974) gives a detailed formula of certain elements of the screen printing process to calculate accurate ink film thicknesses. The key elements revolve around the screen where mesh count (T), thread diameter (d), and emulsion thickness (e) all play a part in the calculation of the ink film thickness (Horwood, 1974,). First, the mesh thickness is determined by doubling the thread diameter (2d). Screen thickness can then be determined by adding the mesh thickness and the emulsion thickness (2d+e) (Horwood, 1974). Horwood (1974) also made note of another variable where he stated, “the warp lines have larger amplitudes (a) than the weft lines resulting in an overall mesh thickness (a+d). Warp and weft describes the characteristics of a weave in fabric, usually weft is the threads running left to right and warp running up and down (Mahon, 2007). Thus, the variation of mesh thickness is due to the warp and weft characteristics of the mesh weave. The pillars of ink are printed through the mesh weave resulting in pillars of ink being deposited onto the substrate. It is also known that, “there are T2 such pillars in a unit square of area,” therefore the total ink volume per unit area can be calculated by the formula: v = [(1/T) - d]2 (ad+e) T2 (Horwood, 1974).

After the ink has been deposited there can be some lateral flow by gravitational stress (Horwood, 1974). However, Horwood (1974) discusses how, “pillars are usually close enough that the pillars merge by surface tension once they are printed resulting in a continuous print thickness (t).” Surface tension

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is the intermolecular force that attracts like molecules at the surface of a liquid (Escobedo and Mansoori, 1996). Therefore, the similar pillars of ink would merge by the attraction force the ink molecules have. Horwood also stated that the possible losses in the pillar merging process such as; surface uniformity, line sharpness, and presence of pinholes are minute enough to be ignored in the calculation process and therefore t = v = [(1/T) - d]2 (ad+e) T2 (Horwood, 1974). The examination of this formula is important because of the relationship between functionality of electric materials and the ink film thicknesses. Research has shown that the conductivity of ink layers depends heavily upon the ink film thickness and it is therefore important to understand the variables related to ink film thickness. Horwood (1974) concludes that this formula can accurately predict ink film thicknesses within ten percent as long as the printing conditions are held constant.

There are a few other variables of the printing process that could affect ink film thickness. Horwood (1974) found that the traverse speed of the squeegee directly affects the ink film thickness. Studies showed that the faster that the squeegee traverses, the thicker the ink film thickness will be (Horwood, 1974). In addition to the squeegee speed, the durometer (hardness) of the squeegee also plays a role in ink film thickness. Softer squeegees lay down more ink (Horwood, 1974). In addition, screen tension exerts force upward against the squeegee affecting the “snap off,� which is the distance between the substrate and the screen (Horwood, 1974). Greater distance between substrate and screen reduces the likelihood of the screen causing ink pick up and thus inadvertently leading to uneven ink film thickness. Screen tension loss occurs over time through the use of the screen. Horwood found that as long as the screen is no less than 50 percent of its original tension, it will produce adequate quality prints (1974).

This project was performed to understand how screen printing variables affect electroluminescent displays. The knowledge of screen printing inks and

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electroluminscent displays gathered and presented in this chapter were used to design the experimental testing.

Research Methods The scientific method is used when experimentation is needed to answer questions correlating with cause and effect relationships of the experiment.

This is done by first identifying and defining the problem that is needed to be resolved. The observer then forms a hypothesis to what the cause of the problem is, in order to prepare for the next step. Experiments are then conducted to collect, organize, and analyze data to further understand the experiment.

The observer then forms a conclusion based on the analyzed data. Testing is repeated to ensure the accuracy of the experiment. The scientific method was used in this experiment to reach conclusions (Science Buddies, 2011).

benchmark test Benchmark analysis was conducted in the labs at the Graphic Communication Department at California Polytechnic State University. The purpose of the benchmark testing was to predetermine the influence of printing speed on surface uniformity and the conductivity of conductive inks in order to narrow down the variables for comprehensive testing.

To determine the variability of electroluminescent displays, a series of twelve benchmark tests were conducted (see Appendix A). A simple test graphic was acquired to analyze the influence of the printing conditions on the conductivity of conductive inks. A monotone “Cal Poly� wordmark, a text only logo, was selected and prepared in Adobe Illustrator Creative Suite 5 (see Appendix B). Two types of inks were tested: silver trace and dielectric. The layers were output, on an Epson Stylus Pro 7880. Each layer was printed on a separate sheet of polyester transparency for screen exposure.

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Polyester screens with a different mesh count were selected: 156 threads per inch (tpi) and 305 threads per inch (tpi). A sheet of Ulano capillary emulsion film with 30 microns of thickness was then applied to each. After the emulsions were applied, the screens were kept at room temperature and in a light-less storage cabinet while they dried.

Screen exposure and preparation was performed in house at the Cal Poly Graphic Communication Department. The positive Cal Poly graphic transparency film was exposed at 40 LTU (light units) with a NuArc 3140 exposure unit. After exposure, the silver and dielectric screens were washed and dried.

Once all preparations of the screens were made, a close examination was performed to check for pinholes and other defects that might cause issues to the finished product. Each screen was then mounted into the ATMA Electric Screen Printer for printing. The press was then prepared for printing by clamping in the squeegee and flood bar and placing the ink onto the screen.

The test form was printed with different printing variables such as squeegee speed. The dielectric layer subjected to different printing processes consisting of multiple printing passes, both wet over wet and wet over dry.

A silver ink provided by Gwent Group was printed though a 156 tpi and a 305 tpi mesh at speeds of 220 millimeters per minute and 440 millimeters per minute to create four silver benchmark samples. All four samples were then sent through a M&R Economax II conveyor drier for 60 seconds at 925 degrees Fahrenheit.

Gwent Group dielectric ink was printed following the same procedures as the silver ink. Dielectric ink was printed with two passes to buildup ink film thickness in order to obtain greater insulation properties. Two experiments were done to understand how printing processes affect ink film qualities: wet over wet and wet over dry.

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The wet over wet layer was printed with two consecutive passes of dielectric ink, one on top the other without drying in between passes. Printing was performed with a 156 tpi and a 305 tpi mesh at speeds of 220 millimeters per minute and 440 millimeters per minute to create four silver benchmark samples. All four samples were then sent through the conveyor drier for 60 seconds at 925 degrees Fahrenheit.

The dielectric ink was also printed as wet over dry. The first pass was printed and dried through a conveyor for 60 seconds at 925 degrees Fahrenheit, and then a second pass was laid on top of the previously dried ink film. Four samples were printed wet over dry similar to the wet over wet printing process.

After printing, the samples were analyzed to verify which variables of printing could produce efficient lighting.

Resistivity is defined as “the fundamental parameter of the material that describes how easily the material can transmit an electrical current. High values of resistivity imply that the material is very resistant to the flow of electricity.

Low values of resistivity imply that the material transmits electrical current very easily� (Exploration Geophysics, 2002). In order to test the electrical resistance of each sample a Fluke 115 ohmmeter was used.

The ink film thickness was another important characteristic of the samples that was tested. A Keyence LK-682 laser displacement sensor was used to measure thickness and height variation (roughness). Each sample was tested using the mentioned devices and recorded in a chart for comparison of the variables.

Once all the samples were tested and measured, the results were then used to infer an optimum combination of print variables that would allow for efficient current conduction and illumination.

Comprehensive test 10

variability of electroluminescent displays

Comprehensive analysis was conducted in the labs at the Graphic Communication Department at California Polytechnic State University.

The purpose of the comprehensive testing was to optimize the screen printing process pertaining to the printing of electroluminescent displays. Displays were analyzed in order to determine how printing variables affect luminance.

Figure 2: Display build sequence (DuPont, 2000)

Figure 3: Display build sequence cross section view (DuPont, 2000)

An EL display is constructed by consecutively printing phosphor, dielectric and silver ink layers on top of a conductive transparent film, ITO (see Figure 2 and Figure 3). An electroluminescent display illuminates when an alternating current between positive and negative is transfered to the phosphor layer,

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which is sandwiched between the two conductive materials: ITO and silver.

The dielectric layer acts as an electrical insulator between the two opposing charges.

A “CP� wordmark was selected and prepared in Adobe Illustrator 5 for assembling the lighting device (see Appendix C). The design was printed with a constant squeegee speed of 220 millimeters per minute. Each of the three layers: phosphor, dielectric, and silver were printed in sequence on a ITO spattered transparency with the same mesh count in order to reduce the number of variables per test and therefore reach more conclusive findings.

The phosphor layer was printed using Gwent Group green ink. After printing, the samples were analyzed to verify which variables of printing could produce efficient lighting. Additionally, four registration marks were added half an inch from all adjacent sides for accuracy in aligning ink layers.

Ink film thickness was measured using a laser displacement sensor. Data was recorded for later print variable comparison for current conduction and illumination.

Results Benchmark test Two inks were printed on 12 micron polyester transparencies to analyze electroluminescent print variables. ink film thickness Ink film thickness for silver and dielectric layers were estimated with a Keyence LK-682 laser displacement sensor. The sensor measures relative ink film height in order to infer ink film thickness. Ten ink film thickness measurements were conducted on each test sample at random locations (156 tpi mesh printed at

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440 mm/min, 305 tpi mesh printed at 440 mm/min, 156 tpi mesh printed at 220 mm/min and 305 tpi mesh printed at 220 mm/min). Readings for each sample were then averaged. One can observe that the relationship between mesh count and speed led to a difference in ink film thicknesses.

Silver ink Table 1: Silver ink thickness across speed and mesh count variables Findings demonstrate that the combination between speed and tpi mesh have an impact on ink lay down. In summarizing Table 1, a greater print speed in conjunction with a lower tpi mesh produced a thicker silver ink film thickness compared to other printing variable combinations. Printing with 156 tpi mesh at 440 millimeters per minute produced a 4.1 micron greater silver ink film thickness than 220 millimeters per minute. Comparatively, printing with a 305 tpi mesh at 440 millimeters per minute produced 3.1 micron greater thickness than 220 millimeters per minute. This is to say that when a tpi mesh of 156 was kept constant there was a 18.6% thicker ink lay down for 440 millimeters per minute versus 220 millimeters per minute. While when a tpi mesh of 305 was kept constant there was a 24.6% thicker ink lay down for 440 millimeters per minute versus 220 millimeters per minute.

Figure4: Silver ink film thickness across speed and mesh count variables Upon observation of Figure 4, one can identify that a lower tpi mesh produced a thicker silver ink film lay down. In keeping the print speed constant, at 440 millimeters per minute, a 156 tpi mesh produced a 9.4 micron greater ink film thickness than a 305 tpi mesh. Comparatively, while keeping the print speed constant at 220 millimeters per minute, a 156 tpi mesh produced a 8.4 micron greater ink film thickness than a 305 tpi mesh. This is to say that

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when a print speed of 440 millimeters per minute was kept constant there was a 42.7% thicker ink lay down for a 156 tpi mesh versus a 305 tpi mesh.

While when a print speed of 220 millimeters per minute was kept constant, there was a 46.9% thicker ink lay down for a tpi mesh of 156 compared to a tpi mesh of 305.

Table 2: Silver ink film thickness standard deviation across speed and mesh count variables The standard deviation of the ink film thickness were used to understand the surface uniformity of the ink films. The surface uniformity has a probable impact on conductivity so it was important to determine which printing variables produced the smoothest surface. In summarizing Table 2, a slower print speed in conjunction with a higher tpi mesh produced a smoother silver ink film surface compared to other printing variable combinations. Printing with 156 tpi mesh at 220 millimeters per minute produced a 0.096 micron less variance in silver ink film thickness than 440 millimeters per minute. Comparatively, printing with a 305 tpi mesh at 220 millimeters per minute produced a 0.0036 micron less variance in thickness than 440 millimeters per minute.

Upon observation of Figure 5, one can identify that a higher tpi mesh produced a smoother thicker silver ink film lay down. In keeping the print speed constant, at 440 millimeters per minute, a 305 tpi mesh produced a 0.0099 micron less variance in ink film thickness than a 156 tpi mesh. Comparatively, while keeping the print speed constant at 220 millimeters per minute, a 305 tpi mesh produced a 0.0161 micron less variance in ink film thickness than a 156 tpi mesh.

Figure 5: Silver ink film thickness standard deviation across speed and mesh count variables

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Dielectric ink The dielectric ink layer was printed with two passes in order to produce a thicker ink film thickness, and thus creating a better insulator between the phosphor and silver layers. The first samples were printed wet over wet. Two dielectric layers were printed consecutively without being dried in between passes. Below are the findings: Table 3: Dielectric ink film thickness across speed and mesh count variables while printing wet over wet In summarizing Table 3, a greater print speed in conjunction with a lower tpi mesh produced a thicker dielectric ink film thickness. Printing with a 156 tpi mesh at 440 millimeters per minute produced a .48 micron greater dielectric ink film thickness than 220 millimeters per minute. Comparatively, printing with a 305 tpi mesh at 440 millimeters per minute produced a 1.97 micron greater thickness than 220 millimeters per minute. This is to say that when a tpi mesh of 156 was kept constant there was a 2% thicker ink lay down for 440 millimeters per minute versus 220 millimeters per minute. While when a tpi mesh of 305 was kept constant there was a 13% thicker ink lay down for 440 millimeters per minute versus 220 millimeters per minute.

Figure 6: Dielectric ink film thickness across speed and mesh count variables while printing wet over wet Upon observation of Figure 6, one can identify that a lower tpi mesh produced a thicker dielectric ink film lay down. In keeping the print speed constant, at 440 millimeters per minute, a 156 tpi mesh produced a 4.83 micron greater ink film thickness than a 305 tpi mesh. Comparatively, while keeping the print speed constant, at 220 millimeters per minute, a 156 tpi mesh produced a 6.32 micron greater ink film thickness than a 305 mesh count. This is to say

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that when print speed of 440 millimeters per minute was kept constant there was a 24.1% thicker ink lay down for a 156 tpi mesh versus a 305 tpi mesh.

While when a print speed of 220 millimeters per minute was kept constant there was a 32.4% thicker ink lay down for a tpi mesh of 156 compared to a tpi mesh of 305.

The second samples were printed wet over dry with the same variables to that of wet over wet. One dielectric pass was printed and allowed to dry prior to a second pass of the dielectric ink.

Table 4: Dielectric ink film thickness across speed and mesh count variables while printing wet over dry In summarizing Table 4, a greater print speed in conjunction with a lower tpi mesh produced a thicker dielectric ink film thickness. Printing with a 156 tpi mesh at 440 millimeters per minute produced a .87 micron greater dielectric ink film thickness than 220 millimeters per minute. Comparatively, printing with a 305 tpi mesh at 440 millimeters per minute produced a 3.5 micron greater thickness than 220 millimeters per minute. This is to say that when a tpi mesh of 156 was kept constant there was a 3.5% thicker ink lay down for 440 millimeters per minute versus 220 millimeters per minute. While when a tpi mesh of 305 was kept constant there was a 20.3% thicker ink lay down for 440 millimeters per minute versus 220 millimeters per minute.

Figure 7: Dielectric ink film thickness across speed and mesh count variables while printing wet over dry Upon observation of Figure 7, one can identify that a lower tpi mesh produced a thicker dielectric ink film lay down. In keeping the print speed constant, at 440 millimeters per minute, a 156 tpi mesh produced a 7.51 micron greater ink film thickness than a 305 tpi mesh. Comparatively, while keeping the print

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speed constant, at 220 millimeters per minute, a 156 tpi mesh produced a 10.14 micron greater ink film thickness than a 305 tpi mesh. This is to say that when print speed of 440 millimeters per minute was kept constant there was a 30.3% thicker ink lay down for a 156 tpi mesh versus a 305 tpi mesh.

While when print speed of 220 millimeters per minute was kept constant there was a 42.5% thicker ink lay down for a tpi mesh of 156 compared to a tpi mesh of 305.

Table 5: Dielectric ink film thickness standard deviation across speed and mesh count variables In summarizing Table 5, a slower print speed in conjunction with a higher tpi mesh produced a smoother dielectric ink film thickness. Printing with a 156 tpi mesh at 220 millimeters per minute produced a 0.00027 micron less variance in dielectric ink film thickness than 440 millimeters per minute. Contrarily, printing with a 305 tpi mesh at 440 millimeters per minute produced a 0.00031 micron less variance in thickness than 220 millimeters per minute.

Figure 8: Dielectric ink film thickness standard deviation across speed and mesh count variables Upon observation of Figure 8, one can identify that a lower tpi mesh produced a smoother thicker dielectric ink film lay down. In keeping the print speed constant, at 440 millimeters per minute, a 305 tpi mesh produced a 0.00094 micron less variance in ink film thickness than a 156 tpi mesh. Comparatively, while keeping the print speed constant at 220 millimeters per minute, a 305 tpi mesh produced a 0.00152 micron less variance in ink film thickness than a 156 tpi mesh.

Table 6: Dielectric ink film thickness standard deviation across speed and mesh count variables

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In summarizing Table 6, a slower print speed in conjunction with a higher tpi mesh produced a smoother dielectric ink film thickness. Printing with a 156 tpi mesh at 220 millimeters per minute produced a 0.0002 micron less variance in dielectric ink film thickness than 440 millimeters per minute.

Comparatively, printing with a 305 tpi mesh at 220 millimeters per minute produced a 0.0002 micron less variance in thickness than 440 millimeters per minute.

Figure 9: Dielectric ink film thickness standard deviation across speed and mesh count variables Upon observation of Figure 9, one can identify that a lower tpi mesh produced a smoother thicker dielectric ink film lay down. In keeping the print speed constant, at 440 millimeters per minute, a 305 tpi mesh produced a 0.0004 micron less variance in ink film thickness than a 156 tpi mesh. Comparatively, while keeping the print speed constant at 220 millimeters per minute, a 305 tpi mesh produced a 0.0004 micron less variance in ink film thickness than a 156 tpi mesh.

Ink resistivity Ink resistivity for the silver layer was estimated with a Fluke 115 Ohmmeter.

Ten resistivity measurements were conducted for each test sample at randomized locations with silver printed over polyester transparencies at one inch increments (156 tpi mesh printed at 440 mm/min, 305 tpi mesh printed at 440 mm/min, 156 tpi mesh printed at 220 mm/min and 305 tpi mesh printed at 220 mm/min). Readings for each sample were then averaged. One can observe that these variables led to differences in resistivity.

Table 7: Silver ink film resistivity across speed and mesh variables Findings demonstrate that the combination between speed and tpi mesh

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have an impact on resistivity. In summarizing Table 7, a higher tpi mesh produced a lower Ohm readings. Printing with a 156 tpi mesh at 440 millimeters per minute produced 9.8 less ohms than at 220 millimeters per minute. Comparatively, printing with a 305 tpi mesh at 440 millimeters per minute speed produced a reading of 3.43 0hms higher than printing at 220 millimeters per minute. This is to say that when a tpi mesh of 156 was kept constant there was a 74% lower ohm reading for 440 millimeters per minute versus 220 millimeters per minute. While when a tpi mesh of 305 was kept constant, there was a 52.7% lower Ohm reading for 440 millimeters per minute versus 220 millimeters per minute.

Figure 10: Silver ink film resistivity across speed and mesh variables Upon observation of Figure 10, one can identify that a higher tpi mesh produced a lower resistivity. In keeping the print speed constant, at 440 millimeters per minute, a 305 tpi mesh produced a reading of .63 less Ohms than a 156 tpi mesh. Comparatively, while keeping the print speed constant, at 220 millimeters per minute, a 305 tpi mesh produced a reading of 6.7 Ohms lower than a 156 tpi mesh. This is to say that when print speed of 440 millimeters per minute was kept constant there was a 17% lower Ohm reading for a 305 tpi mesh versus a 156 tpi mesh. While when a print speed of 220 millimeters per minute was kept constant there was a 51% lower Ohm reading for a tpi mesh of 305 compared to a tpi mesh of 156.

Comprehensive test ink film thickness All inks were printed on 17 micron ITO spattered polyester transparencies.

Ink film thickness for the silver and dielectric layers was estimated with a laser displacement sensor. Ten measurements were conducted on each test sample at random locations (silver ink layer was printed at a constant speed of 220

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mm/min for 156 tpi mesh and 305 tpi mesh, dielectric ink layer was printed at a constant speed of 220mm/min for 156 tpi mesh as wet over wet and wet over dry, and 305 tpi mesh as wet over wet and wet over dry). Readings for each sample were then averaged. One can observe that the relationship between mesh count and speed led to a difference in ink film thicknesses.

Silver ink Table 8: Silver ink film thickness across mesh count The silver ink film thickness measurements from the comprehensive test were consistent with the findings from the benchmark test. In summarizing Figure 11, printing with a constant speed at 220 millimeters per minute a 156 tpi mesh produced a 8 microns greater silver ink film thickness than a 305 tpi mesh. Upon observation of Figure 8B, a 156 tpi mesh produced a 41.6% thicker ink film thickness than a 305 tpi mesh.

Figure 11: Silver ink film thickness across mesh count Dielectric ink Table 9: Dielectric ink film thickness across mesh count and printing process In summarizing Table 9, two layers of dielectric inks, printed by wet over dry method at a constant speed of 220 millimeters per minute with a 156 tpi mesh produced a 6.3 microns greater dielectric ink film thickness than the one printed with the wet over wet method. Comparatively, printing with a constant speed at 220 millimeters per minute with a 305 tpi mesh with the wet over dry method produced a 4.6 microns greater dielectric ink film thickness than the one printed with the wet over wet method. Upon observation of Figure 9B, a 156 tpi mesh printed with the wet over dry method produced a 34% thicker

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ink film thickness than printing with the wet over wet method. Comparatively, a 305 tpi mesh printed with the wet over dry method produced a 33% thicker ink film thickness than printing with the wet over wet method.

Figure 12 Dielectric ink film thickness across mesh count and printing process Upon observation of Figure 12, one can identify that in keeping the print technique constant, wet over wet, printing with a constant speed of 220 millimeters per minute a 156 tpi mesh produced a 4.7 microns greater dielectric ink film thickness than a 305 tpi mesh. Comparatively, printing wet over dry while keeping the print speed constant speed constant at 220 millimeters per minute, a 156 tpi mesh produced a dielectric ink film thickness 3 microns greater than a 305 tpi mesh. Upon observation of Figure 9B, printing with a 156 tpi mesh wet over dry produced a 25.4% thicker ink film thickness than printing wet over wet. Comparatively, a 305 tpi mesh printed wet over dry produced a 24.5% thicker ink film thickness than printing wet over wet.

Resistivity Ink resistivity for the silver layer was estimated with a ohmmeter. Ten measurements were conducted at random locations at one inch increments for each test sample (silver ink layer was printed at a constant speed of 220 mm/min for 156 tpi mesh and 305 tpi mesh on top of dielectric ink printed as wet over wet and wet over dry). Readings for each sample were then averaged. One can observe that these variables led to differences in ink film thicknesses.

Table 10: Silver ink film resistivity across mesh count and printing process Silver ink over ito Upon observation of Table 10, one can identify that silver trace printed over dielectric with a 156 tpi mesh had 3.88 lower ohm readings with wet over wet versus wet over dry. Contrarily, silver traces printed over dielectric with

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a 305 tpi mesh had 62.95 higher ohm readings with wet over dry versus wet over wet. This is to say that when a tpi mesh of 156 was kept constant there was a 38% lower ohm reading for the silver trace printed over dielectric with the wet over wet method versus the wet over dry method. While when a tpi mesh of 305 was kept constant, there was a 80.7% higher ohm reading for the silver trace printed over dielectric with the wet over dry methods versus the wet over wet method.

Upon observation of Table 10, one can identify that in keeping the print technique constant, wet over dry, printing with a constant speed of 156 tpi mesh produced 71.79 lower ohm readings than a 305 tpi mesh. Comparatively, printing wet over wet, a 156 tpi mesh produced 4.96 lower ohm readings than a 305 tpi mesh. This is to say that when printing technique was kept constant, wet over dry, a 156 tpi mesh produced a 92% lower ohm reading than a 305 tpi. While when printing wet over wet, a 156 tpi mesh produced a lower a 32% lower ohm reading than a 305 tpi mesh. silver ink over dielectric ink Upon observation of Figure 13 and Figure 14, one can identify that printing with a 156 tpi mesh produced .11 less ohms with wet over wet versus wet over dry. Comparatively, printing with a 305 tpi mesh produced 1.46 less ohms with wet over wet versus wet over dry. This is to say that when a tpi mesh of 156 was kept constant there was a 12% lower ohm reading for wet over wet versus wet over dry. While when a tpi mesh of 305 was kept constant, there was a 48% lower ohm reading for wet over wet versus wet over dry.

Upon observation of Figure 13 and Figure 14, one can identify that in keeping the print technique constant, wet over dry, printing with a constant speed of 156 tpi mesh produced 2.12 less ohms than a 305 tpi mesh. Comparatively, printing wet over wet, a 156 tpi mesh produced .77 less ohms than a 305 tpi mesh. This is to say that when printing technique was kept constant, wet over

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variability of electroluminescent displays

dry, a 156 tpi mesh produced a 69% lower ohm reading than a 305 tpi. While when printing wet over wet, a 156 tpi mesh produced a lower a 47% lower ohm reading than a 305 tpi mesh.

Figure 13: Silver ink resistivity across mesh count for wet over wet Figure 14: Silver ink resistivity across mesh count for wet over dry luminance Table 11: Luminance for each halftone across mesh count and printing process Upon observation of Table 11, one can identify that printing a 100% solid phosphor with dielectric layer, wet over wet, produced a luminance value of 4.76 brighter for 305 tpi mesh versus a 156 tpi mesh. Comparatively, printing with a 305 tpi mesh a 100% solid phosphor with dielectric layer, wet over dry, produced a luminance value 0.2 brighter than a 156 tpi mesh. This is to say that when a tpi mesh of 305 a 100% solid phosphor with dielectric layer, wet over wet, was kept constant there was a 3.7% brighter luminance versus a 156 tpi mesh . While when a tpi mesh of 305 a 100% solid phosphor with dielectric layer, wet over dry, was kept constant, there was a 0.1% brighter luminance versus 156 tpi mesh.

Upon observation of Table 11, one can identify that printing a 100% solid phosphor with dielectric layer, a 156 tpi mesh produced a luminance value of 9.4 brighter for wet over wet versus wet over dry. Comparatively, printing with a 305 tpi mesh produced a luminance value 14.18 brighter for wet over wet versus wet over dry. This is to say that when a tpi mesh of 156 was kept constant there was a 7.7% brighter luminance for wet over wet versus wet over dry. While when a tpi mesh of 305 was kept constant there was a 11. 2% brighter luminance for wet over wet versus wet over dry.

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Upon observation of Table 11, one can identify that printing a 75% halftone phosphor, wet over dry, with a 156 tpi mesh produced a luminance value 7.8 brighter than a 305 tpi mesh. This is to say that wet dry dry produced a 7.7% brighter luminance for 156 tpi mesh versus 305 tpi mesh. The results for a 75% halftone phosphor was contrary to all other halftone phosphor luminance’s, where 156 tpi mesh had a brighter value than 305 tpi mesh. Due to printing error, the 75% halftone phosphor, wet over wet display was defective.

Figure 15: Luminance for each halftone across mesh count for wet over wet dielectric Upon observation of Figure Table 11, one can identify that printing a 50% halftone phosphor with dielectric layer, wet over wet, produced a luminance value of 16.04 brighter for a 305 tpi mesh versus a 156 tpi mesh. Comparatively, printing with a 305 tpi mesh with dielectric layer, wet over dry, produced a luminance value 2.24 brighter than a 156 tpi mesh. This is to say that when a tpi mesh of 305, wet over wet, was kept constant there was a 16.9% brighter luminance versus a 156 tpi mesh . While when a tpi mesh of 305, wet over dry, was kept constant, there was a 3.1% brighter luminance versus 156 tpi mesh.

Upon observation of Table 11, one can identify that printing a 50% halftone phosphor with dielectric layer, with 156 tpi mesh produced a luminance value of 9.16 brighter for wet over wet versus wet over dry. Comparatively printing with a 305 tpi mesh with dielectric layer produced a luminance value 22.96 brighter for wet over wet versus wet over dry. This is to say that when a tpi mesh of 156 was kept constant there was a 11.6% brighter luminance for wet over wet versus wet over dry. While when a tpi mesh of 305 was kept constant there was a 24.3% brighter luminance for wet over wet versus wet over dry.

Figure 16: Luminance for each halftone across mesh count for wet over dry

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variability of electroluminescent displays

dielectric Upon observation of Table 11, one can identify that printing a 25% halftone phosphor with dielectric layer, wet over wet, produced a luminance value of 11.38 brighter for a 305 tpi mesh versus a 156 tpi mesh. Comparatively, printing with a 305 tpi mesh with a dielectric layer, wet over dry, produced a luminance value 1.68 brighter than a 156 tpi mesh. This is to say that when a tpi mesh of 305, wet over wet, was kept constant there was a 15.8% brighter luminance versus a 156 tpi mesh . While when a tpi mesh of 305, wet over dry, was kept constant, there was a 3% brighter luminance versus a 156 tpi mesh.

Upon observation of Table 11, one can identify that printing a 25% halftone phosphor with dielectric layer with a 156 tpi mesh produced a luminance value of 5.92 brighter for wet over wet versus wet over dry. Comparatively printing with a 305 tpi mesh with a dielectric layer produced a luminance value 15.62 brighter for wet over wet versus wet over dry. This is to say that when a tpi mesh of 156 was kept constant there was a 9.8% brighter luminance for wet over wet versus wet over dry. While when a tpi mesh of 305 was kept constant there was a 21.8% brighter luminance for wet over wet versus wet over dry.

After analysis of the benchmark and comprehensive test data, one can conclude that screen printing variables do affect the luminance of electroluminscent displays.

conclusions Analysis of the comprehensive and benchmark tests revealed that screen printing variables do in fact, affect the luminance value of electroluminescent displays. Printing speed, threads per inch mesh, printing processes such as the wet over wet method and wet over dry method, and the halftone screening of phosphor should be considered when producing EL displays. These

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printing variables, as illustrated in the data presented in chapter 4, influence the conductivity of EL displays and the resulting illumination.

Testing revealed that a lower threads per inch mesh of 156 produced a thicker ink film thickness for silver and thus, held more conduction. Mesh of 156 deposits a greater amount of silver ink which having a greater amount of conductive ink allows the current to flow more readily through a thicker ink film than a thinner film. Results additional revealed that a higher mesh tpi of 305 produced a thinner ink film thickness and it is necessary to print the dielectric layer with 305 mesh for functional EL displays. Conclusive data demonstrated that wet over wet dielectric produced a thinner ink film thickness. Based on the reults, one might conclude that having too thick of a dielectric layer will hinder the brightness of a EL display and thus, a thinner dielectric layer will produce the brightest display. Data also showed that a phosphor layer with a greater dots per inch screening (when comparing 100%, 75%, 50%, 25% phosphor dots) produced a greater value of illumination. The brightness decreases accordingly to the dots per inch screening due to the amount of phosphor present, thus as the light emitting material decreases so does the brightness.

The intent of this research project was to provide standards for, a still not widely documented area of electronic printing. Further testing is still required for more conclusive findings. Proposed future research should include a more extensive degree of variability between ink layers. Potentially, this could mean combining different mesh counts and print speeds between ink layers.

By examining display layer variability in more depth, functional printers can further improve the printing process of displays in order to conclude the optimal variability combination between ink layers. By examining the test results, functional printers can implement printing standards for electroluminescent display printing.

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variability of electroluminescent displays

works cited Escobedo, J., Mansoori, A. G. (1996). Surface Tension Prediction for Pure Fluids.

AIChE Journal, 42, 5, 2.

Exploratio n Geophysics (2002). DC Resistivity Notes http://galitzin.mines.edu/INTROGP/MISC/resnotes.pdf Dr. Rong, X . (2010) Characterize Screen Printing Parameters for Electroluminescent Inks. California Polytechnic State University. 1-10.

DuPont. ( 2000). Processing Guide For DuPont Luxprint速 Electroluminescent Inks.

DuPont Microcircuit Materials. 1-12.

Hart, J. A., Lenway, S. A., Murtha, T. (1999). A History of Electroluminescent Displays, 1-14.

Hensen, S. (2007). A Guide to Screen Printing As a Supremely Accessible Art Form.

1-6.

Horwood, R. J. (1974). Towards a Better Understanding of Screen Print Thickness Control. Electrocomponent Science and Technology, 1, 129-136.

Mahon, J. ( 2007). Weft, Warp & Weave: Understanding the mystery of fabric structure.

SQE Professional, 38-39.

Peaker, A. R . (1970). Electroluminescence and its Applications. Electronics & Power, 329.

Science Bu ddies (2011). Steps of the Scientific Method. http://www.sciencebuddies. org/sciencefairprojects/project_scientific_method.shtml

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Appendix a benchmark test table Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Sample 7 Sample 8 Sample 9 Sample 10 Sample 11 Sample 12

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Silver 156 mesh count / 220 millimeters per minutes 305 mesh count / 440 millimeters per minutes 156 mesh count / 440 millimeters per minutes 305 mesh count / 220 millimeters per minutes Dielectric 156 mesh count / 220 millimeters per minutes 305 mesh count / 440 millimeters per minutes 156 mesh count / 440 millimeters per minutes 305 mesh count / 220 millimeters per minutes 156 mesh count / 220 millimeters per minutes 305 mesh count / 440 millimeters per minutes 156 mesh count / 440 millimeters per minutes 305 mesh count / 220 millimeters per minutes

wet over wet wet over wet wet over wet wet over wet wet over dry wet over dry wet over dry wet over dry

variability of electroluminescent displays

appendix b benchmark test “cal poly”wordmark Cal Poly EL Test Form1.pdf

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1/21/11

3:55 PM

2-Dielectric

Cal Poly EL Test Form1.pdf

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1/21/11

3:55 PM

3-Silver

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appendix c comprehensive test “cp� wordmark

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variability of electroluminescent displays

colophon This journal was produced entirely by students of the TAGA chapter at the Graphic Communication Department of California Polytechnic State University, San Luis Obispo. All design, print production, and overall production work was completed in on-campus facilities.

design Adobe InDesign, Illustrator, and Photoshop CS5.5 were used in the design of this journal, using Arno Pro and Mensch.

Pre-press At the time of writing this stage of the process has not yet been completed.

printing At the time of writing this stage of the process has not yet been completed.

finishing At the time of writing this stage of the process has not yet been completed.

materials Our paper for both the cover and text was very generously donated by ViaStone.

The paper is made from limestone and high density polyethylene, and it contains no tree fibers. Therefore, it is recyclable as a plastic rather than a paper.

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variability of electroluminescent displays

acknowledgements The entire Cal Poly TAGA student chapter would like to recognize the following individuals and companies who have generously supported the production of the 2012 journal.

cal poly graphic communication department Dr. Harvey Levenson, Dr. Penny Bennet, Dr. Ken Macro, Brian P. Lawler, Dr. Xiaoying Rong, Dr. Malcolm Keif, Korla McFall, Kevin Cooper, Bob Pinkin, Nancy Cullins, Lorraine Donegan, Gordon Rivera, Vince Uhler, Eric Johnson, Lyndee Sing, Colleen Twomey, Ivan Bradley, Walt Horelick, Ken Rothmuller, Joy Montoya, Doug Speer.

Special thanks Bob Tapella ViaStone University Graphic Systems

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taga 2012

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Printing With Mobile Applications

by Alicia Juarez

California Polytechnic State University San Luis Obispo College of Liberal Arts Graphic Communication Department December 2011

Abstract The printing industry has implemented a variety of new and innovative technologies to better serve the consumer market. With a high demand and success in mobile technology, the printing industry has an opportunity to play an important role in providing an enhanced printing experience with mobile devices. With success in cloud printing technology and on demand printing strategies, mobile printing would compliment and provide new opportunities of revenue for businesses. The relationship that the consumer has with the interfaces involved with mobile devices and processes will play a strategic role in its success and value.

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Table of Contents

Chapter 1|Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Chapter 2| Literature Review. . . . . . . . . . . . . . . . . . . . . . . 6 Chapter 3|Research Methods. . . . . . . . . . . . . . . . . . . . . 10 Chapter 4| Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Chapter 5| Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Appendix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

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List of Figures

Figure 1 Documents found most useful to print. . . . . . . . . . . . . . . . . . . . . .

Figure 2 File types most used for printing . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 3 Wi-Fi Printer owners and those who plan to own . . . . . . . . . . . . . . . .

Figure 4 Mobile Device that is preferred most by participants. . . . . . . . . . . . . .

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Chapter 1: Introduction The gap between the customer and the printer has taken on new dimensions in the latest technology called Mobile Printing. Through virtual infrastructures such as Wi-Fi technology and cloud technology on the web, information and services can be obtained and accessed to become available anywhere and at anytime. This technology has allowed commercial printers to successfully allow a customer to upload photos for a photo book one night and the next day have it printed and sent out to their home. Photo services like Snapfish and Shutterfly.com are just a few of the many web-to-print businesses that use the web to offer publishing tools for their customers, to personalize their printing and draw on a whole new world of printing options.

These companies have also invested in mobile technologies that allow the ability to place orders with the convenience of a mobile device. The latest software innovations with Apple AirPrint, HP ePrint and Google Cloud, allow devices and laptops to print while mobile without having to be on site. This study asked the question: How can Mobile Printing enhance the printing experience for consumers?

In order to become profitable and maintain success, a business needs to embrace the latest technologies and remain ahead of their competitors and their customers. For example, a consumer views print as a solution for business material, everyday products and special occasion publications, and although it is convenient for the customer to submit jobs through their mobile devices, responsibility for the file submission relies heavily on the customer being aware of the basics of digital reproduction and file submission requirements. For print solution businesses, Mobile Printing removes many steps of traditional printing, because printers have less control of files that a customer submits. The new technology and services are outside of the printers’ domain, which broadens the number of problems that may occur when printing on demand.

What can be controlled and should ultimately be a priority for businesses in print, is to provide an accessible and appropriate interface for a consumer to interact with. Mobile Printing applications can provide a solution that guides a consumer and communicates options for a successful printing

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experience, whether for creative custom print products or everyday work and home printing.

The purpose of this study is to analyze the reliability, quality and functionality of Mobile Printing and the consumer relationship with the technology necessary to provide optimal value and fulfillment. It is necessary to identify current trends in Mobile Printing and how consumers are incorporating these new and growing services.

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Chapter 2: Literature Review The printing industry is a 100 billion dollar industry. Most of the revenue is from large commercial printers, encompassing about 30,000 companies in total. Innovative technology is driving the printing industry both through printing processes and the platforms becoming available to produce print jobs. “Online print production management solutions can save money on reworks, late fees, and obsolete materials. FedEx Office (formerly Kinko's), Mimeo, and NowDocs have online print facilities that enable customers to submit and monitor jobs online, print at the vendor's site, and get overnight delivery. New online services have transformed the printing industry eliminating the costly and time-consuming prepress stage” (FirstResearch).

Among these services, a new form of printing has emerged allowing the convenience of being mobile and to print instantly to any compatible printer.

Both Wi-Fi (Wireless connectivity) and cloud servers (Virtual infrastructures that can access software, services or applications without having one physical location) are used to allow mobile devices to access and transfer data. “These tools allow mobile workers to print to virtually any printer or MFP (Multi Function Printer) available on the network, regardless of location or brand, and reduce the time spent managing print drivers for various devices” (Bawaba, 2006). HP ePrint uses email addresses that are tagged to a printer, which then allows someone to email certain file types to be printed. Apple AirPrint, Google Cloud Print and HP ePrint must have some type of wireless network connection to be able to produce a printed product (Entertainment Close-Up, 2011).

Information is easily exchangeable with products like smart phones, tablets, iPads and laptops allowing media to be accessed anywhere using a network. The few major companies pioneering with Mobile Printing services are HP, Apple and Google. “It is estimated that there will be more than 700 million Internet households and one billion smart phones by 2013,” stated John Solomon an HP representative (Ganesan, 2010). Google and Apple are amongst the first to start

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taking advantage of HP’s ePrint. “By 2014, 90 percent of global Fortune 1000 companies will implement Cloud Printing services for mobile personnel,” states Bruce Dahlgren from HP (HP Debuts HP ePrint Service App for iPhone, 2011). HP has paved the way for the first made Wi-Fi ready printers and competitors like Epson, Brother and Kodak are beginning to catch up with similar technology. “ ‘HP has known for years–mobility is not a trend, it's a way of life,’ stated Bruce Dahlgren, senior vice president, HP” (HP Debuts HP ePrint Service App for iPhone, 2011).

Now that consumers are mobile, both Google and Apple have begun to cater to users with HP’s printer technology.

Apple has been a leading innovator in user-friendly technology and development for their popular devices. With the help of Wi-Fi enabled HP printers, Apple developed AirPrint for use with Apple products such as the iPhone, iPad and laptops. “AirPrint automatically finds printers on local networks and can print text, photos and graphics to them wirelessly over Wi-Fi without the need to install drivers or download software” (Business Wire, 2010). Apple AirPrint is only supported currently by Wi-Fi enabled HP printers. With additional third-party applications such as AirPrint Navigator, a user may also use AirPrint technology to get other wireless printers to print, that are not on the current list of usable printers. An HP executive stated they were, “Making it easy for our customers to print anytime, anywhere… iPad, iPhone and iPod touch customers are going to love how easy it is to print using our new range of ePrint printers, creating high-quality printed pages in an instant" (Business Wire, 2010).

For those who do not use Apple products, Google has a similar technology for both Mac and PC products called Google Cloud Print. Similar to Apple’s AirPrint, users of Google Cloud Print will be able to use mobile applications like a smartphone or tablet and have the ability to print using a familiar Google interface that can print jobs from Google Docs or a Google Chrome browser (Entertainment Close-Up, 2011). Google made an impressive statement on their website, “Our goal is to build a printing experience that enables any app (web, desktop, or mobile) on any device to print to any printer anywhere in the world” (Google). Google has an ambitious goal for on demand Mobile Printing and it is becoming a reality.

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In almost every industry Mobile Printing is becoming a buzzword. Mimeo.com has opened a huge door for print service providers to take advantage of Mobile Printing and be allowed to print to any destination worldwide. “On-demand document printing and distribution–Our mission, to power the worlds print, describes our commitment to providing the world's best workflow for managing documents from anywhere to everywhere” (Mimeo.com, 2011). Mimeo works with Shutterfly.com, a photo site where you can download an iPad or iPhone app to enhance and print photos, photo books and other printed products, while being mobile. Mimeo has strategically placed print facilities in the US to guarantee printed materials to be distributed on time for both commercial and consumer products (Hoover's Company Records, 2011).

There are hundreds of print applications that utilize Mobile Printing services making print more personable and accessible. According to the MobiThinking, “Over 300,000 mobile apps have been developed in three years. Apps have been downloaded 10.9 billion times. But demand for download mobile apps is expected to peak in 2013” (MobiThinking, 2011). This gives print services access to potential consumers for uses from simple document printing to postcard, photos, business cards, calendars and other creative and custom products – all-available through a mobile application. Services like HP’s own Snapfish, Postagram and Silka e-Cards are opening the doors for a more personalized print experience and Mobile Printing is allowing for that accessibility.

There have been several issues that are of concern with the current Mobile Printing technology.

Although HP e-Print is strongly supported by Apple and Google, there were still known issues that are not clearly stated or seen in disclaimers concerning the product and service. Macworld conducted a test using HP e-Printers to test their reliability and time efficiency. The Mobile Printing success rate was above 80 percent with the printers used. Known issues included documents being lost in a cloud, long delays for prints and unreliable email confirmations of printed product (Riofrio, 2011).

While the kinks are being worked out for Mobile Printing connectivity, companies like Intel and Global Graphics are working on ways to compliment and eventually compete with Mobile Printing

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services by using peer-to-peer connections. This technology does not require a cloud server to be used, is secure and can still print from any printer with a Bluetooth or Wi-Fi connection. Global Graphics states, “By moving the processing of office files from the mobile device onto the printer layout, quality and fidelity is significantly improved in comparison with Apple's AirPrint. Also, our performance is significantly higher than that achieved by HP's ePrint" (Wire Feed, 2011). In order for Mobile Printing to be as successful as possible through usability, the technical errors such as connectivity will need to be seamless.

The use of mobile applications will further broaden the opportunities that will become available for consumer print options. Currently 1 to 4 U.S. adults use mobile applications–“mobile app users tended to be younger, male, more educated and more affluent compared to the rest of the population” (Indvik, 2010). There is still a large potential market that may not have the tech savyness to experiment, perform or even be aware of productive utilities available on their device.

This means that whichever application a consumer comes in contact with, especially a printing application, it should provide intuitive navigation and seamless performance.

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Chapter 3: Research Methods The future looks optimistic for services and businesses involved with Mobile Printing. In order for a business to become and remain successful, customer support for all technology levels of consumers will have to prevail. The tools needed to succeed in Mobile Printing will need to be clearly identified. The methods necessary to obtain and evaluate the information will be historical research, descriptive research and content analysis. With this research, the purpose of study will be to evaluate Mobile Printing and the consumer relationship and response to the technology involved.

The first research method being used is historical research. An evaluation of the HP ePrint technology was done with, “MacWorld –24 hours with ePrint”, to compare the printing success of HP Envy 100 e-All-in-One and HP Photosmart eStation, using the HP ePrint technology with an iPhone, Android phone and a Blackberry. Three different files (JPEG, PDF, PNG), were sent and placed using email services from Yahoo, Apple, Gmail and Hotmail that were accessed through the phones internet or Wi-Fi connections. As the printing files were sent from the devices to the printers using the HP ePrint cloud some successfully printed and others were lost and did not (Riofrio, 2011). This research showed the inconsistencies that may come up while using wireless printing.

To interpret and evaluate the current conditions involved with Mobile Printing services, descriptive research will be used. A case study will examine a group of at least 20 people between the ages of 18 and 50 years old. The participants are volunteers that are selected through friends and colleagues from California Polytechnic State University, San Luis Obispo. The individuals have a varied background with technology and little or no experience with Mobile Printing. The devices they will be working with include an iPad and a Vizio Android Tablet. They will access print jobs through a Wi-Fi network. Using Apple AirPrint and HP e-Print the applications that

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will be used to print to an HP Envy printer are HP’s home & biz, Dropbox and Silka eCards for the iPad and HP’s home & biz and Dropbox for the Android Tablet.

The first step in the case study will be to set up the printer and have the applications already downloaded on the mobile device. They will then be given the most common printed file formats such as JPG, PDF, .DOC and PNG. These files will already be downloaded to the device. With the iPad or Android Tablet and with the application designated to their device they will print to the HP Envy 100 while remaining at least 10 feet away from the printer. The directions should be simple enough for them to go through the procedure of selecting the application and from the application complete the task by pushing print. Participants will be timed for each application with a stopwatch from the moment they start the application task, to the time they hit print. The participant will then rate the ease of the devices and complete a set of questions that will be asked pertaining to Mobile Printing.

The next research method that will be used will be content analysis. With the qualitative and quantitative data collected, participants will be able to show the ease of usability of the selected devices and whether or not Mobile Printing and application interfaces allow convenience for users in the following areas of reliability, quality and functionality.

Content Analysis Pie Charts will show the participants preference over the mobile devices used. This will give an idea of which device would be preferred to use with Mobile Printing over others. Another chart will show how often the consumer prints a specific file format. If the device does not perform well with a particular file format this will help developers pinpoint a major flaw in the coding that restricts files to be transmitted to printers. Another pie chart will show what type of content is most likely to be printed using mobile phones such as informational, entertainment, work and financial documents.

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Chapter 4: Results The purpose of this research was to analyze the reliability, quality and functionality of Mobile Printing and the consumer relationship with the technology necessary for a successful experience. After identifying past historical research and current trends in Mobile printing further data was collected and analyzed pertaining to Mobile Applications and the use of them with Wi-Fi enabled printers. In attempt to answer the question how Mobile Printing can enhance the printing experience, a case study was set up with a variety of participants with different technical backgrounds.

Demographics There were a total of 21 participants involved in the Mobile Printing case study and were between the ages of 19 and 48. The average age was 29 years old. The most common printing brand used was HP printers, followed by Canon. The type of documents that were found to be most useful to print were for work or informational purposes. Several responses made an attempt to specify that under work they meant school work. The file types that are most used tend to be PDF’s, .Doc’s and JPEG. Only two of the participants had no access to a smart phone which limited their accessibility and experience with mobile devices.

Activity Questions With the exception of one participant everyone else was quite comfortable with new technology.

When asked which mobile device was perceived to be most comfortable to use, there were stronger responses toward the iPad, than the Android, yet the second greatest response was that participants preferred neither one over the other.

For use with the following Mobile Applications; Dropbox, HP Home & Biz and Silka eCards, participants were consistent in saying that the application interface was not benefiting the ease

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of use when trying to complete a printing task. When answering the short answer question that asked the participants what the most difficult part in transitioning to new technology was for them, there was a united agreement that adjustments were difficult when navigating through multiple interfaces. Participants stated most of the confusion came from the inconsistent symbolism for actions in the different devices and applications. Keeping up with new technology and the ability to afford the gadgets was also of concern. According to one participant, “Having access to the technology and being able to afford it,� was a inhibitor when considering transitions to new technologies.

With companies boasting of how convenient Mobile Printing will be for consumers, there was still a response of over half of the participants not convinced of Mobile Printing benefits or did not see themselves purchasing a Wi-Fi enabled printer. Those who already had a Wi-Fi enabled printer had not used it with a mobile device.

When asked about ordering printed products online to be delivered, there was a consensus toward picking up a product over actually having printed products delivered to their home.

Many of the responses included participants feeling restricted creatively when using online printing services, but agreed that it was more easy, convenient and inexpensive than printing products locally or through a desktop

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printer. One response, related to ordering through an online service stated, “I would [order through an online service], since the quality of my printer doesn’t meet the standards necessary for most of the print projects I have.”

Limitations of the Study The initial set up for the study began with an HP Envy printer.

A network was set up to allow for Internet connectivity while using the mobile devices with their Wi-Fi connection. An IT specialist on site was necessary in order to properly set up a network that would be accessible for the devices. At first network connectivity was very weak until settings were changed by IT. Once Internet access became consistent with the mobile devices the study began. It was noted, that several times when left idle for a couple of minutes, both the iPad and Android tablet would lose connectivity. The solution to this problem was either to restart the device or reconnect to the WiFi network.

The set up for the wireless network proved to be a problem because of the inconsistencies in the wireless connectivity, which affected the download times of the printed assignments. This issue arose in more than a dozen of the participants being studied and forced the omission of the data for the timed results. For four of the participants, the Apple iPad did not print from the Silka E-card application. This was an error that occurred within that application and was resolved by restarting the iPad. During the use of the iPad while using the Dropbox application, only certain files would print directly from the initial application. For example, Dropbox will only directly print document files such as .Doc or PDF’s. It then has any other document such as JPEG or PNG, to be printed externally using utility options from the specific mobile device

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Future purchasing of a Wi-Fi enabled Printer

or going through another application such as HP Home and Biz. This proved to be confusing for the users who had to switch back and forth from applications in order to complete a print for an image file. Respondents found the Android more difficult to work with using image files such as, JPEG and PNG, when viewed through

Figure 3. Participants who currently own a Wi-Fi Printer and those who plan on a purchase or see no need for one.

Dropbox, which kept users from printing the image files,

and only allowing for a zoom option.

While performing the task of printing a web page from the iPad, many users had issues with opening links from the Yahoo.com site. The interface provided was not intuitive when providing a solution for a print option. In some cases a print icon would show up under an article title, but that was inconsistent depending on the web page. Inconsistent symbols, layout and functions from application to application and device, kept the user from efficiently completing a printing task. Many participants would have to click every symbol or viewable option in order to find the correct corresponding printing function.

Chapter 5: Conclusions From the information and responses in the case study there are many issues in the areas of Mobile Printing that must be addressed to make effective improvements to benefit the industry.

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It is seen through this case study conducted, that there is a gap between a consumer and the new technology that is being introduced as beneficial, allowing for efficiency and productivity.

Companies have yet to find a steady way to acclimate their products to consumers who aren’t already involved in new technology.

The majority of participants use their electronic devices primarily for informational, school and work related purposes. Many of these activities include the need to print documents or emails either for references or printed copies. When it comes to functionality, Android tablets have disappointed in providing an accessible way to print documents or images. The absence of a print utility may have been a developer decision that had not been seen as a priority. The purpose of most mobile devices is to substitute large desktop computers or laptops and forgetting such a primary function like a printing option is a huge disappointment. Using market research and developing a well thought

Mobile Device Preferred

out User Interface with printing options, will only provide a better user experience when on a mobile application.

Although Apple is noted for their sleek and simple User Interface many users on the iPad were

Figure 4. Mobile Device that is preferred most by participants.

confused and hesitant when trying to complete a printing task. This may be a response to the inconsistencies found in many mobile applications that are being downloaded and developed by different design companies. These companies have backgrounds with a wealth of knowledge on User Experience and User Interface design, but there are also companies with little or a lack of this essential knowledge. The participants relied heavily on symbols used throughout the applications to navigate through the appropriate functions to complete a task. These symbols should remain

17

consistent and relevant to the function of the button or action. Google and Apple have websites dedicated to User Experience and User Interface design, yet they are just guidelines. It is difficult to find consistencies in this area because of intellectual copy right on symbols and designs, but finding a consistent placement or intuitive symbolism will remain a must in providing effective productivity and functionality.

The majority of participants did not own a Wi-Fi enabled printer, nor did they plan to own one.

When asked why, a participant stated, “No real need at the moment [To purchase a Hp e-Printer].

Having Wi-Fi on a printer may be useful in the future.� Advertisements for gadgets create needs and solutions for us and have an allure that propose a product will solve many issues and allow for greater convenience. These conveniences found in technology would vary depending on the consumers lifestyle. Any lifestyle at one point or another will be in need of an email, photo, work or school document that they will need to print. Mobile printing will become more prevalent as the solution to many of these needs as the demand in mobile devices, such as Android Tablets and iPads continue to soar.

18

19

Appendix

20

21

Appendix: Data Work Informational Entertainment

10 8 2

Documents found most useful to print

PDF JPEG .Doc

11.5 3.5 5

File types most used for printing.

4 No Need for Wi-Fi Printer Plan to own WiFi Printer 5 Currently Own 12 Participants who currently own a Wi-Fi Printer and those who plan on a purchase or see no need for one.

Apple iPad (Most Comfortable)

9.5

Android Tablet (Most Comfortable) Neither

7.5 4

Mobile Device that is preferred most by participants.

Note: Some particiants had two first choices which resulted in .5 incriments when adding data to graphs.

22

References Bawaba, A. (2006 26-September). Xerox Mobile Offerings Make it Easier for Office Workers to Print

From Anywhere, Anytime. London.

Business Wire. (2010 15-September). Apple's AirPrint Wireless Printing for iPad, iPhone & iPod touch.

Business Wire .

Entertainment Close-Up. (2011 4-April). HP ePrint-enabled Printers Now Support Google Cloud

Print. Entertainment Close-Up .

Ganesan, S. (2010 18-July). Now, print while being on the move. The Hindu .

Google. (n.d.). Google Cloud Print. Retrieved 2011 27-April from Google.com: http://code.google.

com/apis/cloudprint/docs/overview.html

Hoover's Company Records. (201115-April). Mimeo. Mimeo.com, Inc. Hoover's Company Records. (2011 26-April). Shutterfly, Inc. Retrieved 2011 26-April HP Debuts HP ePrint Service App for iPhone. (2011 24-April). Health & Beauty Close-Up .

Indvik, L. (2010 14-09). Mashable. Retrieved 2011 06-10 from 1 in 4 U.S. Adults Now Use Mobile

Apps: http://mashable.com/2010/09/14/mobile-apps-pew-survey/

Mimeo.com. (2011). About Us. Retrieved 2011 26-April from Mimeo.com: http://www.mimeo.com/

aboutus/

MobiThinking. (2011 07). Global mobile statistics 2011. Retrieved 2011 6-10 from Mobithinking.com:

http://mobithinking.com/mobile-marketing-tools/latest-mobile-stats

Riofrio, M. (2011). 24 hours with ePrint. Macworld (60).

Wire Feed. (2011 22-March). Major Advance in Mobile Printing. Wire Feed .

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taga 2012

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jacksonville ---------------------------------california polytechnic state university san luis obispo

vol. 3 -----------Mobile web design and usability -----------by caitlin watt

vol. 3 -----------Mobile web design and usability -----------by caitlin watt

taga 2012

---------------------------------

jacksonville --------------------------------california polytechnic state university san luis obispo

Copyright Š 2012 by California Polytechnic State University, San Luis Obispo Technical Association of the Graphic Arts, Student Chapter All rights reserved. All material in this book has been compiled with the knowledge and prior consent of those concerned, but is published without responsibility for errors or omissions. Nothing in this publication shall be reproduced without the express written consent of the authors and editors. Every effort has been made to ensure that credits accurately comply with information supplied. We apologize for any inaccuracies that may have occured.

First published in the United States of America by: Cal Poly TAGA Student Chapter One Grand Avenue San Luis Obispo, CA 93407 Printed at California Polytechnic State University, San Luis Obispo

the printing press is either the greatest blessing or the greatest curse of modern times, sometimes one forgets which it is ------------E. f. schumacher

vol. 3

mobile web design and usability -----------by caitlin watt

introduction By 2012, it was predicted that more mobile devices would be manufactured than Personal Computers (PCs), and that PC usage would drop by 20%, while mobile device usage picks up the slack. The mobile industry is growing fast, driven by the advances in mobile device technology as better browsers are implemented and screen resolution increases. As the mobile technology advances, the mobile user experience evolves due to the increased usage of smartphones and tablets. Because of the jump in mobile device usage, there is an increase in mobile web activity as more people are accessing the Internet through a mobile device.

This opens up a new market for businesses, as their websites are being accessed everyday by customers on mobile devices rather than from customers using a desktop computer, such as a PC, that provides at least 13� of viewing space. Mobile devices have small screens with only an inch or two of viewing space, revealing the increasing need for businesses to have mobile friendly websites to cater to the growing mobile market. The term “Mobile Friendly� is commonly used to describe websites that have adapted to the small screens of mobile devices. This study asks: What are the current trends for designing and improving usability on a mobile device, and to what extent are businesses successfully creating a mobile friendly companion website to cater to mobile user needs?

Websites viewed on a smart phone need to include certain aspects to ensure the best functionality. Most importantly the audience has to be kept in mind, for they will be viewing the site when a desktop computer is not available. The user will be viewing the site on the go, so the information needs to be presented in a clear and legible way. Type should be readable and set in an appropriate size so that it can be effortlessly read despite the small size of the screen. Only essential information should be available on the first page with a simple navigation so the user can be easily directed with no difficulty. The user also needs their information immediately so pages must be optimized so they load. Images should be in the appropriate resolution and size in order to provide a positive user experience for the mobile viewer.

The physical aspects of the mobile device need to be considered as well. The two most used smart phones to date are the iPhone and the Android phones which have a touch screen. Touch screens change the browsing experience completely because your finger becomes the mouse, and hovering options are not available.

It becomes extremely important to know how to change a design so the user can easily ‘tap’ instead of ‘click’. Also, phones such as the iPhone and Android phones have the capability of switching between portrait and landscape viewing, adding completely new dimensions for the design. Every mobile device is different in size and shape making it essential for a design to be able to resize accordingly.

Mobile devices are an increasingly important way to access the Internet. Many businesses are discovering that mobile web is vital to their business and websites designed for a desktop computer do not transfer well to a small screen. Companies are adopting strategies to make mobile companion sites and some are proving to be more successful than others.

The purpose of this study is to improve mobile browsing experience and to learn the steps to optimize design for small handheld devices. Mobile web has proven to be a necessity and is the most growing market for the Internet. Discovering how people browse on their mobile device will help provide insight for designing a visibly pleasing page, while also catering to the needs of the user. A detailed analysis on how businesses are able to create a mobile friendly website and a comparison of a desktop version and a mobile version is performed in this study that will help determine the best practices for designing for mobile web.

literature review Over 63 million people in United States accessed the Internet through a mobile device in the year 2010. By 2013, it is predicted that there will be over 1.7 billion using the Mobile web worldwide (Chapman). According to Morgan Stanley, by 2020, desktop Internet will be over taken by mobile Internet as “more people will caitlin watt

use their mobile devices to access the Internet than their desktop or laptop computers.” JiWire’s public Wi-FI study has found that 56 percent of connections are from mobile devices such as Android smart phones and the iPhone (Axon). Mobile Internet has proven to be a main player in Internet usage today, but some design factors are holding back successes and affect the future of mobile web design.

It was not until 2000 that the wireless world really started to take off with the launch of Internet on mobile phones and it was not received well by the public. At the time only a few mobile phones had built-in Web browsers which were expensive, and it was nearly impossible to find websites that worked on mobile phones (Camp).

According to Graham Camp, “customers didn’t like it, content companies didn’t like it, and wireless carriers didn’t like it. It was a good recipe for a failure, as we all know now.” The idea was well known and frequently talked about, but not in the best regard. Many doubts and skepticism held back the development of the mobile web. Most innovative technologies take time to prosper, which is why desktop web design must be addressed before moving into mobile web design.

In 2000, the desktop Internet was still in its beginning stages and at this point users were predominantly using dialup Internet. Browsers were primarily textbased with no graphics or any thought of design (Sauter). First impressions count especially in the way the Internet is used today, where people browse quickly and “form opinions about the look of your website in 1/20th of a second” (Bradley).

As a result of this, the design of a website is an important factor in the success of an organization.

Steven Bradley, a Web Designer and Developer, feels that the best web designs are ones that are simple.

Great web designs keep out of your way and don’t draw attention to the design itself. Some of the best designs are those you’ll never notice because the design has allowed you to move right into the process of interacting with the site, finding what mobile web design and usability

you want as quickly as possible and moving on to the rest of your life. (Bradley) Although Bradley’s statement is describing desktop web design, it has direct correlations to designing for mobile devices but to a greater extent. Mobile devices are meant entirely to be used on the go, when a computer is not available. Bradley’s statement about finding information quickly needs to be emphasized and brought to the next level when designing for a phone.

Today, accessing websites via phones and mobile devices are dominating the way users browse the Internet. Because of this, designers have the growing need to become educated in mobile design to accommodate this booming audience. The most important concept that all designs will depend on is functionality.1 It cannot be stressed enough how important functionality plays into design. The designer must know their product before they can even attempt to start the creative process (Camp).

Steven Snell from Smashing Magazine knows how to strategically deal with the unique situations and challenges that play in the mobile layout. Key aspects that will improve functionality are simplicity, white space, lack of images, and prioritized content. Simple options for scaled-down screens are essential, especially when Internet connections are often slower, stressing the importance of users accessing the most crucial parts (Axon). The simplicity is received as refreshing in the “age of crowded pages.” Cameron Chapman a designer for Noupe website, agrees that “your mobile site, in most cases, should be simpler than your standard site” and that this might mean “redoing your menus, eliminating images, breaking up text over multiple pages, or otherwise re-working your site’s layout and functionality.”

White space also plays into the simplicity aspect. Snell believes it is an important part of any design but to actually implement it into a mobile web design proves to be a challenge as the typical screen size is so much smaller. All web designers have to work with varying screen sizes, but mobile screen sizes are more of a challenge then desktop screens. Screen sizes are always changing with the trends, while older sizes are still in use. The most commonly used resolution is 960x640 caitlin watt

pixels for the iPhone 4, and they are improving each year with sharper resolution and larger screens.

Images can “often do more harm than good.” High-speed connections are common for home computing in the recent years, but mobile devices still lag with excessive image use that hinder the users ability to access information fast. Because of this it is “very common to see minimal use of images in mobile Web design.” Logos and icons are fine as long as it does not interfere with optimization or loading time. Last of all, “simplicity of these pages and the general lack of many options, the content displayed is highly prioritized.” All websites need to be user-focused resulting in the fact that many mobile websites are ad-free, even though advertisements have become widely accepted on the Internet. Many mobile websites have a search bar or a store locator field as the first thing that comes up on a page, knowing that the user is probably trying to search for something specific or trying to find a location while on the go. Functionality, for Chapman, includes limiting scrolling to one direction. Chapman that it is really annoying to have to scroll in multiple directions especially on a touchscreen mobile device, as it is easy to accidentally scroll in the wrong direction. Chapman also advises avoiding pop-ups or links that open new windows on mobile websites. They interrupt the browsing experience so only use them when imperative, and if used, make sure to alert mobile visitors before their appearance.

Understanding how users interact both physically and visually with a mobile device has helped with the design aspects of browsing, but another equally important factor are the most popular browsers used. Opera, a popular web browser, collects data every month in their State of the Mobile Web report with a list of the top ten visited sites on a mobile device in various countries. As of January 2011 in the United States, a few of the top ten are as following: google.com, facebook.com, wikipedia.org, twitter.com, yahoo.com, and accuweather.com. A majority of theses sites are search engines and social media sites. People like to stay connected with friends and family and the easiest way is through their phone. Search engines are mobile web design and usability

on the top of the commonly accessed sites for obvious reasons: finding answers to everyday questions.

Other important markets working their way to the top ten are shopping pages.

According to Adobe’s Mobile Shopper Insights for 2011, 73 percent of users shop online for an hour a week on average. It is becoming common for shoppers to research a product at the point of decision “transforming the way consumers shop and interact with brands, and retailers that are not investing in this channel may risk getting left behind� (Adobe). One main insight that Adobe focused on is how users are more likely to type in their search directly into the search bar rather than downloading applications. This tremendously helps with how to design a mobile website that accommodate the preferences of the user. It also helps predict where the future of mobile device usage will lead.

Mobile devices are proving to have a major role in how users access the Internet today. They are predicted to become the primary device used to browse the Internet.

Not only are they changing the way users access information, but how websites are designed. Mobile devices are offering more opportunities for business to reach their target markets, through new mediums such as the mobile web. It is important for businesses to utilize mobile web design to expand markets and improve business success. However, understanding how to conceptualize mobile web design, and how users experience browsing websits from a mobile phone, is key for businesses to successfully utilize the benefits that a mobile device offers.

Methodology To determine how to improve mobile browsing usability and to what extent businesses are successfully creating a mobile friendly companion website, this study employed interviews, surveys, and Content Analysis. Deciding how to design in the mobile web field is a very subjective task. Because of this, the research process will not be the same as researching a scientific study. Different methods of research can caitlin watt

be used to find solutions for creating a functional mobile web page that is ascetically pleasing. One method in determining what processes work for mobile web is to ask industry professionals in Elite and Specialized interviews. Asking experts in the web design industry who have seen the transition to mobile web and know the increasing importance of this field of design will bring great insight on how it is done. Analyzing what experts are saying about mobile web, and determining what factors are the most important, will lead to surveying a variety of people for their opinions in mobile web usage for Descriptive Research. The last method is Content Analysis, turning data into predictions, which will aid in determining answers for this subjective topic. Using Content Analysis will bring together all surveys, interviews, and Descriptive Research into a solid, quantitative data that will support a solution for designing functional mobile websites, complementing their desktop counterparts, leading to the increase in business. (Levenson) Talking to experts in the mobile design business is a valuable way to determine what aspects of design produce a successful website. The professional’s opinions and experience in the industry will improve this study and improve the previously collected research. Talking to professionals, specifically from Fertile Minds and LEVEL studios, two web design firms that work with smartphone development is essential for a complete research. The interviews will be conducted based off conversation, as that is how Dexter defines the method of using Elite and Specialized interviews. The open general questions that will start the interview will be: What are the first steps in the process of designing and creating a layout for a small screen size? How do you decide what goes on the mobile version? What do you suggest to the client are the most important aspects that should be presented on a mobile friendly site? How has mobile web impacted your business in the last few years with the increase in mobile device popularity?

Another type of research that is essential for gathering information about the trends of mobile design is Descriptive Research. Questionnaires and surveys complete what cannot be gathered from interviewing experts. A study will take a group of mobile web design and usability

individuals and allow them browse mobile friendly websites on a mobile device and compare the experience with browsing on a desktop.

For the study, a group of 26 Graphic Communication students have been tested on browsing websites on a desktop computer and a mobile device. These students are from a senior level class, with different levels of experience in browsing on mobile devices. In a controlled lab, they were told to browse two specified sites, one mobile friendly one not. They were first told to browse the two websites, webdesigndepot.com and thedieline.com, on a iMac 27 inch desktop screen and answer a few questions based on their experience. Then they browsed the same two websites, on either an iPhone or an Android mobile device and answered a few questions based on their experience. After experiencing both modes of browsing, the students were able to share their opinions on how well they felt the desktop version of the website was translated into the mobile version. The survey questions asked from the desktop version for both websites are as follows:

DESKTOP 1) How many levels of navigation did you find on the main (home) page?

2) Do you find the site easy to navigate?

(Rate on a scale of 1-5. 5 being the easiest)

1

2

3

4

5

Comments: 3) Do you find it easy to search for content on the website?

(Rate on a scale of 1-5. 5 being the easiest)

Comments:

caitlin watt

1

2

3

4

5

4) Do you find the content (headings, captions, body text) easy to read?

(Rate on a scale of 1-5)

1

2

3

4

5

Comments: The survey questions asked from the mobile version for both websites are as follows:

MOBILE (please stay in portrait mode for questions 1-4)

__ iPhone

__ Android

1) How many levels of navigation did you find on the main (home) page?

2) Do you find the site easy to navigate?

(Rate on a scale of 1-5. 5 being the easiest)

1

2

3

4

5

Comments: 3) Do you find it easy to search for content on the website?

(Rate on a scale of 1-5. 5 being the easiest)

1

2

3

4

5

Comments: 4) Do you find the content (headings, captions, body text) easy to read?

(Rate on a scale of 1-5)

1

2

3

4

5

Comments:

mobile web design and usability

5) Switch to landscape mode. Do the elements scale to fit the screen?

Circle one. Yes No 6) Are there any elements that you saw on the desktop version that you wish were incorporated into the mobile version? (ex. Option to post comments) Comments: 7) On a scale of 1-5 (5 being the best) how did this site’s mobile version compare to the desktop version in relation to design and functionality?

Comments:

1

2

3

4

5

Additional Comments:

After all of the research is gathered, a Content Analysis will be completed on the gathered research. A rating scale was used to show the preferences collected in the surveys making it easy to present information in a numerical way. The findings from the study are generalized and described in the results section along with the answers to the interview questions from Fertile Minds and LEVEL Studios. With all the data collected, it will give a further understanding of the process of creating and converting a desktop website to a mobile website.

development of study This study found answers to questions about mobile browsing usability and what aspects of desktop websites transfer well to a mobile version. This section of the study presents the results in two parts: Elite and Specialized Interviews, and a survey. Elite and Specialized Interviews were carried out with industry professionals who have useful information in regards to mobile web development. The caitlin watt

survey shows the opinions of mobile users, which are helpful in determining what aspects of mobile web are preferred, and how well desktop versions of a website are transferable to a mobile version.

Interviews To further understand users preferences when using a mobile device to browse the Internet, an insight in the process and decisions made to create a mobile version of a website is imperative. To receive this viewpoint, this study interviewed Dusty Davis. Davis is a graphic designer and founder of Fertile Minds Media, a web design and development company. Because Fertile Minds Media is a small company, his job requires him to work in all aspects of the web design industry, such as working with clients, designing, coding, and marketing. Davis is a part of every aspect in their web design, projects, and therefore a valid candidate to further understand how mobile has made an impact on the user experience.

When working with a new client, the first step is to analyze the demographic. If the demographic is in 50 plus range, then the budget will not be spent on creating a mobile version of the website. It also depends on what type of site you are dealing with. One of Fertile Minds Media’s clients is promoting an event for a marathon, where it becomes imperative for customers to have access to last minute information from their mobile devices. All the work and design that has been perfected on the full site goes out the window, and you are left with just a small window containing only vital information. In this instance, customers would use the mobile version to look up locations and maps for the marathon. Davis states that a mobile version is not just a scaled down version of a website, but rather a companion site, that takes advantage of the limited screen real estate, that is redesigned to cater to customer’s mobile needs.

Normally a website is approached with the intention of having a mobile version from the start. It is not often that you go back on an existing design and create a mobile version. As Fertile Minds Media begins building a site, a desktop version mobile web design and usability

and a simple mobile version are made simultaneously. When working on a mobile version, narrowing it down to the absolute most important message is key. The main information is typically displayed as the first thing the user sees, with the navigation at the bottom of the mobile version, rather than the top like the desktop version. There is not a set layout for a mobile version, and it may not mimic the desktop version in terms of layout. When it comes down to what goes on a mobile website, the client ultimately makes the decision. Some clients are really sophisticated and come to web designers just for technical assistance, while others are completely dependent on the web designer to take control of the project and lead the client in the right direction.

With a small firm, such as Fertile Minds Media, there are no formal testing methods or analysis done on a finished mobile website to check user experience. Instinct and knowledge of the workspace from experience becomes imperative to testing what will work on a mobile device.

Data connections are improving constantly, but load times may cause frustration, especially on mobile devices. To improve loading times on a mobile website, limit everything and minimize files as much as possible, by getting rid of blank spaces in HTML coding. Flash should be left out completely, but javascript still translates well on a mobile device, as long as it is not a complicated long file. Mobile devices have browsers that are fully capable of handling the desktop version of a website, especially some of the Android phones that have a typically larger screen then an iPhone. Some companies go straight to the full site for a mobile device if it detects a large screen size.

There is an increase in demand for mobile companion sites that will increase in the next few years. The growing concern around mobile web design proves that it is becoming a requirement as opposed to an option when it comes to web design.

All clients now expect to have a mobile version made to complement the desktop version, and pixel-perfect layouts for mobile versions are made simultaneously with caitlin watt

desktop versions. Versions for tablet sizes are also in demand. Data connectivity is improving and hopefully will help loading times for mobile devices.

This study also interviewed Rob Patti, a technology manager at LEVEL Studios.

He focuses on the development aspects of building websites and understands the technological side. LEVEL Studios works with clients such as Apple and RIMM, where they have a design team and a marketing team. Patti works directly in the development side of web design and has insight and experience in the process of building a website.

When approached with a project, it is clear what the client will want in terms of mobile. Most clients want a mobile version designed to accompany the desktop version. There are some cases when the client as an existing site and they want to optimize a website for mobile. Clients usually have a plan in mind for what information they would like on the mobile version. A solution is generally recommended to the client, which includes removing aspects that are nor necessary from a mobile standpoint. Sidebar content with related articles are elements that are usually transferred over to the mobile version, but may be kept on smaller versions such as a tablet size.

Due to cost involved very few studies or focus groups have been done to test user experience from a mobile perspective. Mobile web is still relatively new and is constantly growing, making it more difficult to test in the same respect as a desktop.

At LEVEL Studios, there is a user experience group, which follows best practice, but typically they just get in the mind set of a mobile user, and relate the experience to how they would browse or use their mobile device. LEVEL also focuses on understanding what the target market for each project or client would prefer.

LEVEL Studio develops mobile versions with different processes. One way is to create a sub-domain, such as m.thedieline.com, that automatically redirects the user according to the screen size of the device that is accessing the web content. mobile web design and usability

The trend now is to use HTML5, which does not redirect the user to a sub-domain, but rather just has the content resize to fit the size of your screen, no matter the device that is accessing the information. It is best to avoid using device detecting content, but rather us HTML5 which provides seamless transitions from one screen size to the next. Flash is avoided, but javascript works well. Mobile devices support the vast majority of javascript and CSS, buts some elements do not transfer well. Resolution has not been an issue, except in exporting images for higher resolution devices.

It is important to take into account other screen sizes, which has proved to be a main source of frustration for Patti, when asked about his browsing experience on a mobile device. It is easy to design on a computer that has a 24� monitor, but size considerations is a problem. Some major issues most commonly seen in mobile browsing are small fonts, inconsistent colors, and bad designs. According to Patti, it is important to fully optimize a mobile version of a website, and if not it is better to leave a website as is, because users are already used to zooming in and exploring a full-sized site.

HTML5 is going to push the envelope for mobile web. Creating a separate mobile website, such as using a sub-domain site, will become obsolete and not worth the time and money. Having to support two sources of content, or two sources of code bases is impractical. You will want to build a site that is optimized to support mobile devices. Mobile should be considered with every new project. Even if a client does not specifically ask for a mobile version, the web developer can at least educate their client and propose solutions.

Survey For this study, a survey was given after comparing the desktop version of a website and a mobile version. The survey helped determine how users experience and interact with the content displayed in the two very different ways. This survey was meant to get a better understanding of how well some websites translate to caitlin watt

a mobile device.

The testers were asked to view two websites on a desktop and then view the same two websites again, but on a mobile device (iPhone or Android). The purpose was to see the content of the website in both versions was perceived by the user. The results of this user experience survey revealed the strengths and weaknesses of both websites and showed how well each website compared directly to its companion site. The first website tested was webdesignerdepot.com, which has a very prominent design, and many levels of navigation.1 The mobile version had a lot of the design stripped out but still had a great look. The second website tested was thedieline. com which has a beautiful and simple design, but the mobile version proved to be lacking in optimization.

The first category testers were asked to compare was the levels of navigation and to rank the ease of use on a scale of 1-5 (1=Very hard to use, 2=Somewhat hard to use, 3=Neither hard nor easy to use, 4=Easy to use, 5=Very easy to use). Desktop versions typically have a least three levels of navigation and often there are additional sidebars and related information. Webdesignerdepot.com particularity has a design heavy desktop version, but was able to narrow down its navigation to only three levels on the mobile version. On average the navigation for the desktop version, tested as 3.24, meaning that the users felt that the navigation was neither hard nor easy to use.² The mobile version tested as 4.44, ranking it as easy to use.

Thedieline.com had three essential levels of navigation, but on the mobile version only one level of navigation was available for the user. The desktop version tested navigation as 4.36, ranking it as easy to use, while the mobile version was tested as 2.6, low on the ranking scale at somewhat hard to use.

¹ see Appendix B ² see Appendix C ³ see Appendix D

mobile web design and usability

The second category the testers were asked to rank was the searchability of content on the website. Webdesignerdepot.com has an easy to see search bar right at the top of the page and tested as 4.0 for the desktop version. The mobile version also has a search bar at the top of the page, so it was not surprising when the users tested it as 4.44, easy to use. According to comments on this category, it was clear that the users liked having the search bar in a prominent position in both versions, improving the browsing experience.続 For thedieline.com, the desktop tested as 3.6, neither hard nor easy to use, even though the search bar is located at the bottom of the page. The mobile version proved to be much harder to use as it tested as 1.92.

The users commented on how hard it was to search because there was no search bar on the main page at all.

The testers were also asked to rank the readability of the content, such as headings, captions, and body text. Having the content presented in a clear and easy to read fashion is very important to retaining a users attention. Webdesignerdepot.com tested on average as 4.28, easy to use. The developers of webdesignerdepot.com did well at presenting the articles with big headers and having body text with wide margins.

The mobile version tested as 4.64, somewhat easy to use. Thedieline.com tested as 4.84, on the high end of easy to use, while the mobile version tested as 4.44, also easy to use. The testers expressed in the comments that the lack of margins made the body text more difficult to read.

The testers were also asked to switch to landscape mode on the mobile device to rank how the website rescaled to fit the different dimensions. Both websites did scale to fit landscape mode, but thedieline.com only had the body text rescale. The images stayed the same size and did not reposition. Testers expressed in the comments that they would have preferred a better layout for the landscape mode, as it is a popular way to view a website on a mobile device.

The most important question at the end of the study was to ask the users how well the mobile version compared to the desktop version in relation to design and caitlin watt

functionality. Overall, testers preferred the mobile version of webdesignerdepot.com, and it was even expressed, in most cases, that the mobile version was even better than the desktop version; testing at 4.56, easy to use. The users felt that the mobile version incorporated all the important aspects from the desktop version and no aspects were clearly missed that were only on the desktop version. Thedieline.com did not fair well as the website’s average ranking tested as 2.56, somewhat hard to use. The users were disappointed in the mobile version, which they felt was very lacking in design and functionality.

Overall, the interview results provided insight on how to incorporate mobile web to accompany desktop websites. It is important to address the designs of a mobile version of a website early in the web development process. Mobile versions are not just scaled down versions of a website, but rather a companion site to accompany a desktop website. Also, the study on mobile web usability provided insight for improving mobile web design and revealed which design trends prove to be successful.

conclusion This study set out to determine how to improve mobile browsing experience and to learn the steps to optimize design for small handheld devices. The result is a clear plan on the process of designing a mobile companion site to work along side its desktop counterpart, and the best practices to use to offer the greatest browsing experience for users.

The importance of catering to mobile users has proven to be a high priority for web developers. Developers are no longer just designing a desktop website, but they are now involved in developing different versions to accommodate for the variety of device screen sizes. Internet browsing from a mobile device is common, increasing the demand for mobile website compatibility. From this study it was determined that the most common practice of developing a mobile website is to mobile web design and usability

design a companion site at the beginning of all web development. Mobile design had originally been incorporated as an after thought to the desktop versions, but with the popularity of smart phones it has become a vital piece for web development that is taken into consideration from the start. Fertile Minds Media and LEVEL Studios both stressed the importance of this concept of developing all layout designs for all sizes from the beginning. This will increase consistency and ensure the transferability of each aspect across all platforms.

As all forms of a website are being developed simultaneously, it becomes clear what elements should be incorporated to optimize a mobile version. Simplicity is clear, especially on a mobile device when loading times are slow and visibility is not guaranteed in every situation. Mobile users take more time browsing and do not click as freely as on desktop versions, where speed and connectivity are more consistent. Simplicity and basic layouts are key as was proven in the results from the study, especially in relation to navigating through a website.

Two levels of navigation for a mobile device was preferred according to the testers.

The mobile version of webdesignerdepot.com had only two levels and ranked as very easy to use, while thedieline.com had one level and ranked as hard to use. The testers commented on how webdesignerdepot.com had the perfect number of navigation levels; one at the top and one at the bottom where it is easy to redirect once scrolling to the bottom of the page. This seems to be the best practice according to the study to improve usability. In addition to navigation, the ability to search content on a web page was also tested in the study. On a mobile device, where it is imperative to get information quick, a search bar should be present. The testers preferred the search bar to be located at the top of the page rather than the bottom, where it is more likely to be missed. Readability proved to be adequate for both websites in both versions. It is concluded that margins should be included around all bodies of text and images to improve appearance.

According to the comments from the study, many testers expressed frustrations caitlin watt

with loading times. Experts from the interviews revealed that these issues could be improved easily in the HTML markup. Web developers should keep files organized and not have any extra lines of code that are not being use, which are the most common reasons for slow loading times. Concise techniques are key to improving the browsing experience.

All the aspects discussed in this study should improve the mobile web browsing experience. The results gave clear answers to what users experience mobile websites when comparing them to a desktop version. All mobile websites should have minimal levels of navigation, and include search bars to improve users’ browsing experience. Simplicity is key for mobile layouts. Busy designs distract users from the content of the website. Businesses incorporating mobile versions for websites shoudl follow these simple tips to ensure mobile website success and improve browsing for their customers.

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References Cited ADAPP T . “History of Mobile Web Browsing: Mobile Website Development.” Mobile Website Development & Design: Cincinnati, OH. 2010. Web. 02 Feb. 2011. <http://iadappt.com/home/history.html>.

Adobe M obile Commerce Survey. “Mobile Shopper Insights for 2011.” 23 Feb. 2011. Web. Feb 2011. <www.adobe.com> Axon, Sa muel. “Half of Public Wi-Fi Connections Aren’t From Laptops [STATS].” Social Media News and Web Tips and The Social Media Guide. 24 Feb. 2010. Web. 03 Feb. 2011. <http://mashable.com/2010/02/24/jiwire-wi-fi-stats/>.

Bradley, Steven. “The Importance of Web Design.” Van SEO Design. 17 Feb. 2006. Web. 03 Feb. 2011. <http://www.vanseodesign.com/web-design/the-importance-ofweb-design/>.

Camp, G raham. “A History Of The Mobile Internet.” Aug. 2008. Web. 03 Feb. 2011. <http:// e-articles.info/e/a/title/A-history-of-the-mobile-Internet/>.

Chapma n, Cameron. “Mobile Web Design: Tips and Best Practices.” Noupe Design Blog.

09 Feb. 2010. Web. 03 Feb. 2011. <http://www.noupe.com/how-tos/mobile-webdesign-tips-and-best-practices.html>.

Sauter, M artin. “Why The Mobile Web Had Such A Terrible Start.” WirelessMoves. 07 Dec. 2007. Web. 04 Feb. 2011. <http://mobilesociety.typepad.com/mobile_ life/2007/12/why-the-mobile.html>.

Snell, St even. “Mobile Web Design Trends For 2009.” Smashing Magazine. 13 Jan. 2009.

Web. 03 Feb. 2011. <http://www.smashingmagazine.com/2009/01/13/mobileweb-design-trends-2009/>.

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Appendix a Example of a well designed website and its mobile companion site: Bankofamerica.com

desktop

Mobile

mobile web design and usability

Appendix b Desktop and mobile versions of the websites used in study: Webdesignerdepot.com

desktop

Mobile

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appendix b (continued) thedieline.com

desktop

mobile

mobile web design and usability

appendix c Graphs of study results:

Webdesignerdepot.com DESKTOP

MOBILE DEVICE

5 4 3 2 1

NAVIGATION

SEARCHABILITY

READABILITY

DESIGN & FUNCTIONALITY

Thedieline.com DESKTOP

MOBILE DEVICE

5 4 3 2 1

NAVIGATION

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SEARCHABILITY

READABILITY

DESIGN & FUNCTIONALITY

appendix d Written comments from study: Webdesignerdepot.com

DESKTOP 1) Do you find the site easy to navigate?

“Too many web banner ads on right sidebar...then the navigation is easy to read” “Navigation is far away from the top and gets lost” “Navigation not visible; have to scroll to find navigation” 2) Do you find it easy to search for content on the website?

“Big search box” “Prominent search bar” 3) Do you find the content (headings, captions, body text) easy to read?

“Nice contrast” “Too busy!”

“Easy to distinguish between headings, body text but still not easy on the eyes”

MOBILE 1) Do you find the site easy to navigate?

“So much easier to find and see navigation compared to desktop” “I love the categories at the top and it is easy to see multiple stories at once” 2) Do you find it easy to search for content on the website?

“This site is in good order & also has a search bar” 3) Do you find the content (headings, captions, body text) easy to

mobile web design and usability

read?

“Clean and simple” “Good contrast and clean typeface” 4) How did this site’s mobile version compare to the desktop version in relation to design and functionality?

“The mobile website is almost easier to deal with because it’s not over crowded with other elements” “I like the mobile version better”

Thedieline.com

DESKTOP 1) Do you find the site easy to navigate?

“A lot going on but can easily get through” “It was a little cluttered-my eye didn’t know where to land” 2) Do you find it easy to search for content on the website?

“They have a search bar and also have good categories within navigation” “Directory page is great, no search tool though” 3) Do you find the content (headings, captions, body text) easy to read?

“Lots of contrast, simple font” “All the fonts are really clean”

MOBILE 1) Do you find the site easy to navigate?

“You just scroll down- nothing to really navigate” “Navigation at bottom of page; have to scroll through multiple articles before reaching it” caitlin watt

2) Do you find it easy to search for content on the website?

“No search bar!”

3) Do you find the content (headings, captions, body text) easy to read?

“Not as beautiful as the desktop version” “Readable, but lack of side margins is weird”

appendix d (continued)

4) How did this site’s mobile version compare to the desktop version in relation to design and functionality?

“Lots of issues with repeating divs which means I missed out on a lot of content” “Mobile version is definitely limited”

mobile web design and usability

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mobile web design and usability

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mobile web design and usability

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jacksonville ---------------------------------california polytechnic state university san luis obispo

vol. 4 -----------using optical character recognition to identify legibility of non-western languages -----------by jennifer owen

vol. 4 -----------using optical character recognition to identify legibility of non-western languages -----------by jennifer owen

taga 2012

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jacksonville --------------------------------california polytechnic state university san luis obispo

Copyright Š 2012 by California Polytechnic State University, San Luis Obispo Technical Association of the Graphic Arts, Student Chapter All rights reserved. All material in this book has been compiled with the knowledge and prior consent of those concerned, but is published without responsibility for errors or omissions. Nothing in this publication shall be reproduced without the express written consent of the authors and editors. Every effort has been made to ensure that credits accurately comply with information supplied. We apologize for any inaccuracies that may have occured.

First published in the United States of America by: Cal Poly TAGA Student Chapter One Grand Avenue San Luis Obispo, CA 93407 Printed at California Polytechnic State University, San Luis Obispo

before printing was discovered, a century was equal to a thousand years ------------henry david thoreau

vol. 4

using optical character recognition to identify legibility of non-western languages -----------by jennifer owen

Introduction Many printers in the United States are printing products that are used overseas.

When printing a language that is not understood by anyone at a facility, it becomes difficult to determine the legibility of those characters. A representative from one such company that prints packaging for hospital sterilizers in 11 different languages mentioned that they have the most difficulty printing Kanji on plastic substrates using flexography. This study will show that it is best to use optical character recognition software to identify print defects in non-western languages.

Kanji is a form of Japanese writing that originates from Chinese characters and typically contains pictograms. There is currently no specification regarding tolerances of readability for printing Kanji, which leaves the printers guessing whether or not the characters are readable. The problem with this system is that a print defect has the potential of changing one Kanji character into another. Many pharmaceutical companies that run into this problem use on-press cameras to make comparisons between the running product and previously accepted product. This process is known as halftone comparison or dot-to-dot comparison and results in a large amount of waste because the product it is rejected without question if it is not exactly the same.

Optical character recognition (OCR) software reads scanned images and turns them into editable documents. OCR can be used to read printed Kanji samples and find acceptable variations in print defective products. The purpose of this study is to see if it is viable to use OCR to determine legibility of non-western languages.

Using Kanji as the basis for research, the results will show that OCR can be used to inspect defects in order to waste fewer products.

Literature Review Written Japanese incorporates three different alphabets: Hiragana, Katana, and Kanji. Hiragana and Katana are often combined and referred to as Kana. Kanji originates from Chinese characters and typically contains pictograms that are

more complicated than Kana. The characters represent ideas or words, instead of syllables or letters, and have different meanings when combined with other Kanji characters. Many Kanji characters can also be read and pronounced differently based on context (The Kanji Site). Over 50,000 Kanji characters exist; however, in 1981 the Japanese government introduced a list “which includes 1,945 regular characters, plus 166 special characters used only for people’s names. Government documents, newspapers, textbooks and other publications for non-specialists use only these Kanji characters” (Ager).

When printing Kanji in the United States, it can be difficult to determine how print defects compromise legibility. One stray dot or smear has the potential to change the Kanji character. Typical flexography defects result from the pressure between the plate cylinder and the impression cylinder being either too low or too high.

When the pressure is too low, the entire image is not transferred; and when the pressure is too high, there can be dot gain and halos.

These defects are especially an issue in the pharmaceutical industry where the effects of many products could mean life or death. Although the human mind is brilliant and capable of deciphering text that is distorted to a certain degree, pharmaceutical companies cannot take the risk associated with someone not being able to read instructions or dosages. To avoid risk and ensure quality, many pharmaceutical companies use cameras on the production line to make comparisons with previously accepted and rejected products. “Systems for high-speed production line inspection enable insights into processes that are running too fast for the human eye to follow” (Vaczek). However, “the advantages that automated inspection offers in higher accuracy and labor cost savings must be balanced with the potential for lost productivity deriving from high false reject rates. ‘An enemy of acceptance of machine vision technology is the impact on productivity, from rejected product that should have passed as good product,’ says Michael Soborski, director of inspection solutions, central engineering group, Systech International” (Vaczek). In other words, too much product is labeled as unacceptable because it is not a dot-for-dot match to previously accepted product, even though it is still

adequate. Variations are acceptable “from a human-readable standpoint, but if you have a font recognition engine that is not tolerant of those variations, you will get false rejects” (Vaczek).

To avoid wasting product, some pharmaceutical companies have added advanced self-monitoring to their quality checks. Cameras are still used to pull out rejected product, but an operator then checks those products for legibility. For example, Symetix, a capsule and soft gel integrity company, uses a self-monitoring system for inspection of soft gel capsules. Although this process is done for the capsule itself and not the printing, the imaging concept is the same. The system looks for variations in size, shape, color, etc. “When a rogue capsule or defective product is identified, the system automatically removes the problem from the product stream. Pictures of all rouge-classified product are presented to the operator and stored in a batch file” (Vaczek). The operator then checks the product for humanreadability and accepts or rejects the product. An additional feature of separate checking is the operator’s ability “to save an image of a failed product, and flag and post images of subsequent similar failures, for continuous identifying of what has failed and why” (Vaczek).

Although it is possible to hire a Kanji reader, that method is subjective. Companies must have a quantifiable system to identify defects. To avoid hiring a linguistics expert, companies can add optical character recognition (OCR) software to quality checks. For example, Systech International “has released next-generation software for optical character recognition that the company says is more responsive to normal acceptable manufacturing variances” (Vaczek). To accommodate for normal variations and defects, “the company streamlined the font-training process, which develops character libraries used to score inspected images” (Vaczek). The system takes common print variations and “predicatively puts those variations into the font library, which makes the font training faster and more user-friendly” and helps to avoid false rejects (Vaczek).

OCR is a “method for the machine-reading of typeset, typed, and, in some cases,

hand-printed letters, numbers, and symbols using optical sensing and a computer” (“Optical Character Recognition”). When a document is scanned, the light reflected by the text is “recorded as patterns of light and dark areas…” (“Optical Character Recognition”). “The OCR software then processes these scans to differentiate between images and text and determine what letters are represented in the light and dark areas” (Lals). The term ‘optical’ is actually “a bit misleading, as modern OCR software does not use optical character recognition, but actually uses digital character recognition” (McGuigan). The reason for the confusion is that as technology advanced, the two fields merged, adopting the more commonly known name of optical character recognition.

When OCR software first emerged, it “required training the program on a specific font before it could be accurately input” (McGuigan). Each font had to be entered in and stored for the software to recognize it. Scanning, a document that used a font that was not stored would result in a high level of errors, as the software would use the closest match that it could find. Newer OCR software adds “multiple algorithms of neural network technology to analyze the stroke edge, the line of discontinuity between the text characters, and the background” (Lals). Taking into account irregularities of ink and paper, “each algorithm averages the light and dark along the side of a stroke, matches it to known characters and makes a best guess as to which character it is. The OCR software then averages or polls the results from all the algorithms to obtain a single reading” (Lals). These “more intelligent systems are now the norm. The methods used are now relatively static, with only a little bit of research going into developing entirely new methods, and most research going into refining existing procedures to make them ever more accurate” (McGuigan).

Research Methods and Procedures The purpose of this study was to establish if it is viable to use optical character recognition (OCR) software to determine legibility of non-western languages.

More specifically, OCR was tested for recognition of pharmaceutical printing.

The current process of determining legibility with image comparison results in a large amount of waste. To show that OCR is a better tool for testing legibility, the scientific method was used.

As defined in Dr. Harvey Levensonâ&#x20AC;&#x2122;s book titled Some Ideas about Doing Research in Graphic Communication, the scientific method involves five steps. These steps are: identify and define the problem; formulate a hypothesis; collect, organize and analyze data; formulate conclusion; and repeat, verify, and modify the research.

The first step, identify and define the problem, has already been completed. The problem is the amount of waste that is created using the current method of determining legibility. For step two, formulate a hypothesis, my hypothesis is that OCR is more accurate and will reduce waste.

For step three, organize and analyze data, samples were printed, scanned, and run through an OCR software program. The original artwork was from a company that prints pharmaceutical packaging using Flexography. The artwork was edited down to two paragraphs of text containing a warning about product use and storage. One paragraph was in English and the other in Kanji. The samples were printed on a Mark Andy 2200. Four different types of samples were printed.

The first had perfect impression. These samples would have passed a dot-for-dot image comparison. The second had too low impression. The impression during the press run was turned down until the image became lighter and, in some cases, disappeared completely. The third had too high impression. The impression on the press was turned up until halos began to appear. The fourth had the impression turned up as high as possible. One hundred samples of perfect impression, high impression, and maximum impression were collected, while ninety-six samples of low impression were collected. The difference in sample size occurred because less low impression samples being printed. After printing, the samples were separated by language. To ensure accuracy, both the English and Kanji samples were run through the same scanner and OCR software. The scanner used was a Fujitsu Scan Snap S510M and the OCR used was Adobe Acrobat Professional. To easily track samples, each one was split up by its sample group and language, and then

labeled with its own sequence number, one to one hundred.

For step four, formulate conclusion, the OCR results were checked to confirm accurate character recognition. To repeat and verify, step five of the scientific method, individuals read the samples and confirmed legibility. Conclusions were made based on three different result scenarios: 1) Samples were legible based on image comparison and confirmed humanly readable, but not recognized by OCR. 2) Samples were not legible based on image comparison, but recognized

by OCR and confirmed humanly readable.

3) Samples were considered not legible by all three checks.

Results The purpose of this study is to see if it is viable to use OCR software to determine legibility of non-western languages. Kanji was used as the basis for research due to its unique and complicated characters. Both English and Kanji samples were printed on a Mark Andy 2200 press, scanned on a Fujitsu Scan Snap S510M, and run through Adobe Acrobat Professional. Four different groups of samples were collected: perfect impression, decreased impression, increased impression, and maximum impression. These four settings were used to represent common press behavior. To verify the findings, individuals unaware of the OCR results then looked at the samples and determined legibility. The results of each test were then compared and a conclusion was made based on what percentage of waste could have been saved by OCR. Perfect impression was considered to be the optimum printing level. All text was visible and contained no halos or smearing. These samples would have passed a halftone dot comparison with complete accuracy. The results of the perfect impression samples are shown in the following table:

On each table, an â&#x20AC;&#x153;xâ&#x20AC;? indicates a sample that was determined legible. This table shows that out of one hundred English samples, a reader determined that one hundred were legible, and OCR determined that eighty-two were legible. Out of one hundred Kanji samples, a reader determined that one hundred were legible, and OCR determined that eleven were legible.

For samples with decreased impression, the impression was reduced until the text became light. On some samples, parts of the text disappeared completely. These samples would not have passed a halftone comparison test. The results of the decreased impression samples are shown in the following table: This table shows that out of ninety-six English samples, a reader determined that seventy-six were legible, and OCR determined that that thirty-two were legible.

Out of ninety-six Kanji samples, a reader determined that thirty-nine were legible, and OCR determined that three were legible.

The third test group contained samples that had the impression increased until halos began to appear. Had these samples been run through a halftone comparison, they would not have been exact matches and would have been wasted. The results of the increased impression samples are shown in the following table: This table shows that out of one hundred English samples, a reader determined that one hundred were legible, and OCR determined that eighty-four were legible.

Out of one hundred Kanji samples, a reader determined that one hundred were legible, and OCR determined that fourteen were legible.

The final group of samples had the impression set as high as possible. These samples would not have passed a halftone comparison and would have been wasted. The results of the maximum impression samples are shown in the following table: This table shows that out of one hundred English samples, a reader determined that seventy-eight were legible, and OCR determined that nine were legible. Out

of one hundred Kanji samples, a reader determined that twenty-one were legible and OCR determined that zero were legible.

The results of each test were then examined and a percentage of waste saved was established based on the number of samples determined legible. The results of the Kanji samples and their representative percentages are shown in the following table: Although the perfect impression samples would pass a halftone comparison and not need to be run through OCR, the chart shows that with OCR alone, 89% percent of the samples would have been wasted. Meanwhile, 3.13% of the low impression samples would have been saved and 14% of the high impression samples would have been saved, but none of the maximum impression samples would have been saved.

The results of the English samples and their representative percentages are shown in the following table: Were OCR to be used alone, the chart shows that 18% of perfect impression samples would have been lost, 33.33% of the low impression samples would have been saved, 84% of the high impression samples would have been saved, and 9% of the maximum impression samples would have been saved.

Conclusion The result of the tests done on both language samples show that the amount of waste created was greater than the amount of waste saved. Therefore, OCR by itself is not a viable tool for checking legibility of non-western languages. Using OCR alone would only increase the amount of waste the Pharmaceutical printing companies have.

The OCR software used in this test was a simple version with few settings and

basic functions. For practical use, more advanced OCR software is needed. Since there is “no such thing as perfect OCR… choosing a program to buy comes down to extra features: multi-lingual support, one-touch scan and conversion integration, automatic PDF conversion, and whole-word recognition across specialized disciplines like legal and medical fields” (McGuigan). In this instance, having a software package with broader language availability or specialized recognition should increase OCR results.

One example of broader language availability comes from IRIS, a company that creates solutions for document and information management. IRIS has its own OCR program called Readiris, which has an Asian language version. This package contains additional forms of Japanese, Chinese, Korean, and even Hebrew that are not available in most programs (I.R.I.S.). Another example comes from Nuance, a company that provides speech, document, and imaging solutions. Nuance’s product, Omnipage, claims an accuracy rate 50% greater than most programs.

Omnipage also includes “recognition dictionaries for financial, legal, and medical specialties [to] ensure the most accurate conversion of important industry-specific terms” (Nuance).

Another issue when choosing OCR is price. The cost of OCR has a broad range and generally increases with features and accuracy. Readiris Pro 12 Asian costs $249.00 and Readiris Corporate 12 Asian costs $589.00 (I.R.I.S.). Omnipage 17 for at home use costs $149.99. Omnipage Professional 17 costs $499.99 (Nuance).

Although OCR alone was not successful in reading non-western languages, OCR in combination with other on-press imaging systems may save a more significant amount of waste. More advanced OCR is recommended and further testing is needed to confirm the best combination of on-press imaging and OCR.

Works Cited Ager, Simon. “Japanese Kanji.” Omniglot. 2010. Web. 21 October 2010. http://www. omniglot.com/writing/japanese_kanji.htm I.R.I.S . 2009. Web. 1 March 2011. http://www.iriscorporate.com/c2-1-17/I-R-I-S---OCR-Software--Document-Management-Solutions-and-Complex-IT-Infrastructure. aspx Lals, Sami. “QuickStudy: Optical Character Recognition.” Computerworld. 29 July 2002. Web. 21 October 2010. http://www.computerworld.com/s/article/73023/ Optical_Character_Recognition Leven son, Harvey. Some Ideas about Doing Research in Graphic Communication. 2001. p19-21 McG uigan, Brendan. “How do I Choose the Best OCR Software?” WiseGeek. 08 September 2010. Web. 21 October 2010. http://www.wisegeek.com/how-do-i-choose-the-bestocr-software.htm Nuance. 2011. Web. 2 March 2011. http://www.nuance.com/ “Opti cal Character Recognition.” Columbia Electronic Encyclopedia, 6th Edition (2009).

Academic Search Elite. EBSCO. 21 October 2010. http://web.ebscohost.com/ehost/ detail?vid=1&hid=14&sid=9984f025-9da9-4847-8996-89c108e9dece%40sessionm gr4&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=afh&AN=39025742 The Kanji Site. 2001. 20 October 2010. Web. http://www.kanjisite.com/index.htm Vacze k, David. “INSPECTION SYSTEMS: Looking Closer at Inspection.” Pharmaceutical & Medical Packaging News. 29 May 2008. Web. http://www.pmpnews.com/article/ inspection-systems-looking-closer-inspection

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Comparing Components of Flexography Printing for the Application of Oxygen Barrier Inks on Films

Graphic Communication Department California Polytechnic State University, San Luis Obispo

by Kasey Renee Reed June 2011

Š 2011 Kasey Reed

Table of Contents Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Chapter One Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Purpose of Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Chapter Two Introduction Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Chapter Three Purpose of Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Research Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Materials and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Chapter Four Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Table 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Chapter Five Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2

Abstract The purpose of this study is to appraise typical components used in flexographic printing of functional inks on filmic substrates when printing packaged products inline.

An oxygen barrier coating was applied using different plate-screening technologies and anilox rolls. Comparing two plate-screening technologies and three different anilox rolls using oxygen permeability tests helped to conclude the optimum plate and anilox roll solution that best apply the ink for proper functionality of the coating, with minimal ink application as to reduce waste.

Further knowledge of printing oxygen barrier coatings inline will yield results that benefit in both production and cost areas. Selection of the right combination of plate technology and anilox roll which achieves similar results of barrier properties available in pretreated films will allow companies to cost-effectively achieve maximum barrier assets in their packaging.

The first print run comparing the different plate screening technologies revealed that the capped plate technology provided higher barrier properites than the cell patterned technology. With the capped plate technology used in the second print run comparing the anilox rolls, optimum results attainted disclose the combination of these two flexographic components for achieving maximum functionality of barrier inks. Using the 360 CPI, 6.53 BCM anilox roll with the capped plate technology, the barrier properties created are competitve with pretreated filmsâ&#x20AC;&#x2122; properties. Benefits of inline printing versus pretreated films are found in both cost and production areas.

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Chapter One - Introduction Today, a majority of packaging is printed with flexography and a fair amount of flexography is printed on filmic substrates. Filmic substrates include plastic films that often come as a large roll, for web printing. Functional barrier properties are the characteristics found among certain inks and coatings that serves to prevent one or more gasses or liquids from permeating the package.

Smart packaging technologies include inks with barrier, sensor, and scavenging properties. These available techniques may control oxygen, carbon dioxide, ethylene, moisture, or odor which help to improve shelf life or product quality. While plastic films with precoated protective barrier properties can be purchased, having a tractable way of printing these functional inks inline may prove to be more cost effective. When printing with functional inks it is critical that the application of ink meet the specified requirements to ensure the purpose of the â&#x20AC;&#x153;smartâ&#x20AC;? and specific function.

In flexographic printing, the anilox cell volume and the printing plate, used as the image-carrier, are the primary controlling factors in ink transfer. Since there are several technologies used to enhance the ink transfer on printing plates, comparing these technologies will indicate the optimal plate technology for printing functional coatings onto films. Two plate-screening options for flexography printing were tested: plate cell patterning and capped plate technologies.

Background Three popular forms of intelligent packaging include sensors, scavengers and barriers.

With a focus on barrier coatings, comparing different screening technologies reveals the best plate technology to optimize the functionality of these materials. The anilox roll selected for the print run is dependent on the printed productâ&#x20AC;&#x2122;s characteristics

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and needs. Primary characteristics that need to be considered when deciding which anilox roll to use for a flexographic print run include: the angle of the cells, the carrying capacity of the cell (cell volume), and the number of cells per linear inch (line screen) (Hamrick). In the case of printing functional inks with specific barrier properties, anilox roll selection becomes even more important because of the requirement of specific densities to ensure proper functionality of the ink. This study asks: What is the best combination of anilox roll characteristics and plate technology to ensure the optimum application of functional inks, such as an oxygen barrier coating? While a high volume, anilox roll will provide a thick application of the coating, a combination of the capped plate technology and a medium volume anilox will apply the full functionality of the ink without excess material use.

Purpose of Study The purpose of this study is to evaluate different components found in flexographic printing to provide more knowledge on the use of printing functional inks on filmic substrates in packaged food products when printing inline. The application of the oxygen barrier coating using different plate-screening technologies and anilox rolls using oxygen permeability tests is compared to determine the plate and anilox roll that best apply the ink for proper functionality of the coating. Further knowledge of printing with oxygen barrier coatings inline will provide results that benefit in both cost and production efficiency. Choosing the right combination of plate technology and anilox roll can achieve similar results of these barrier properties that are available in pretreated films, but can be applied in a more cost effective manner. From this research, further understanding will be gained on achieving similar results with cost and production efficient methods of barrier coating application.

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Chapter Two - Literature Review There are several components of flexographic printing that are controlled before or during a pressrun. When it comes to printing specialty inks, it is important that these specifications be met in order for the inks to properly function. Two of these controlled components include the printing plate and the anilox roll. The plate serves as the image carrier for the ink lay-down between the ink metering system and substrate, and the anilox roll is designed to supply a uniform volume of ink onto the plate. Having an understanding of plate and anilox roll variables will help in choosing what plate or roller will maximize the functionality of specialty inks.

Intelligent packaging has come a long way to ensure customer satisfaction. With ways of controlling oxygen, carbon dioxide, ethylene, moisture, odor and temperature, smart packaging can address numerous packaging problems. While intelligent packaging devices are narrowed down to the capability of sensing and providing information about the properties of the packaged food, active packaging includes components of packaging systems that have been deliberately included in or on the packaging material to enhance the performance of the package system (Kerry). Other current intelligent packaging options, aside from oxygen barrier ink, also exist. These include sensors and scavengers.

A sensor is a device that detects or measures a physical property and records, indicates or otherwise responds to it (Kerry). An example of using sensors in smart packaging is the AgeLess Eye by Mitsubishi Gas Company. The AgeLess Eye is a colorimetrix redox dye-based indicator, in tablet form, placed inside a package to indicate the presence of oxygen in one glance (Mitsubishi). When exposed to oxygen, it turns blue, returning to its original pink appearance as soon as the oxygen is eliminated.

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A scavenger, in chemistry, is a substance added to a mixture in order to react with, or otherwise interact and remove impurities or unwanted reaction products (ChemiCool).

An example of this absorber in packaging is an oxygen scavenger in the form of a sachet. The mixture of chemicals found in the sachet, mainly salt and iron, react with the water and oxygen for elimination. Therefore the contents of the bag can sift through the oxygen in the packaging and moisture from the food to chemically create rust inside the bag; hence removing the oxygen from the package (Kaufman). Another example of a scavenger comes in the form of a film. For an ethylene film, the ethylene absorption agent is bound to films through polymer processing and then placed inside the packaging, as a liner or sheet. This liner/sheet then absorbs the ethylene gas as it is emitted inside the package (Research Gate).

The focus of this study is the barrier functional component of smart packaging. Barrier works as a limit or boundary to restrain or keep out anything unwanted, designed to be impervious to gas migration (Sargeant). An example of this is a film that resists oxygen permeation. The film is usually multi-layer with the outer top layer being a strong plastic, the inner layer being a thin layer of gas barrier material, and the inside or bottom layer is almost always a soft, low-density polyethylene (Sargeant). An alternative of using a composite material is to coat a plastic with a barrier coating.

Printing plates are a main component in controlling the print quality in flexographic printing. There are many ways of altering a flexographic printing plate to change the ink acceptance properties. One technique is to add a screening technology to the plate.

In plate cell patterning, screening engines place cells in the solid areas of the plate by imaging them on an imagesetter or directly onto the plate unit (Nexus). The cells found in the solid areas serve a similar function to the cells found in anilox rolls, providing a

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more uniform ink film. The results include lower ink consumption, less pressure required during the printing process, improved solids, and finer positive images (Nexus).

Capped plates are another plate technology. Capped plates have a micro-rough cap layer covering the entire plate which helps produce excellent ink transfer for both solid coverage and fine dot reproduction (MacDermid). When printing specialty inks, it is advantageous to use a plate technology method to increase ink lay-down in order to achieve the ink thickness required with minimum waste.

Comparing a control plate with two different printing plates reveals which plate technology attains maximum functionality and conservation. This is possible by measuring the oxygen transmission rate (OTR). An OTR test reveals the amount of oxygen that passes through the coated film, revealing its permeability. Permeability is how easily an element transfers through a solid substrate. A low value reveals a large resistance to the unwanted component, while a high value reveals a low resistance. The OTR inspection assesses the polypropylene film that is printed with the oxygen barrier coating, providing a quantitative measure of oxygen passing through the film in a cm3/ m2/24hrs format. The smaller the number, the less oxygen that passes through the film.

Anilox rolls are the metering roll designed to consistently supply a uniform volume of ink onto the plate, or image carrier (Kenny). There are three main characteristics that make up the discreet differences between anilox rolls. Two of these components have a more prominent effect when printing with specialty inks. These characteristics are key to matching specifications that differ among inks. The three characteristics include the engraving angle of the cells, the cell volume and line-count.

In the case of printing with oxygen barrier ink and the large solid area coverage, having

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control of the engraved cell angle and the cell volume assist in the functionality of the ink. The engraving angle determines the shape of the cells and usually is provided in three angles: 30 degrees, 45 degrees and 60 degrees (Lanska, January). While the 45 degree cut provides a diamond-shaped cell, the 30 and 60-degree angle yield hexagonal cells. The shape of these cells is critical because the hexagonal shape produces 15 percent more cells per square inch of surface area than the diamond shape (Lanska, January). While the cell count is more critical in higher resolution printing or finer-line reproduction, it does come affect the oxygen barrier coating in terms of waste. When applying an oxygen barrier coating, the functionality of the ink will be increased as the ink film is increased. However, once a critical thickness has been achieved, getting a thicker ink application is wasteful. While large cells have low numbered cell counts for more volume, balancing cell size ensures a more beneficial use of the ink by only applying the thickness required for its functionality.

The cell volume is the second and more critical component in having control of ink application in flexographic printing. The cell volume, which refers to the ink capacity of the cells, tells how much ink each cell can hold (Shawn). The common unit of measurement is billion cubic microns per square inch (BCM). Cell volume is essential to the process because it gives the best inclination of the amount of ink that will actually be delivered to the plate, and then to the film. The amount of ink that is transferred to the plate from the anilox roll is often referred to as the delivered volume. While the cell volume tells us how much ink the cells are capable of holding, the delivered volume tells us how much ink actually transfers out of the cells. Since printing with specialty inks requires a precise thickness of ink application, it is crucial that the cell volume is delivering the correct amount of ink. With various factors impacting the delivered volume, such as the viscosity of the ink, doctoring method system used, and surface tension of the plate and substrate, it is vital that the delivered volume is predictable

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(Lanska, January).

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Chapter Three - Methodology Purpose of Study The purpose of this study is to evaluate two different variables found in flexographic printing. There are several variables considered in the process of applying an oxygen barrier coating inline; components including anilox roll specification, plate characteristics and doctor blade condition. They can be adjusted or replaced in order to accommodate certain printing requirements, such as attaining a specific ink film thickness during the printing process. While it is important to reach a specific ink thickness in order for the proper functionality of the coating, applying more ink than necessary is wasteful.

Comparing the application of the oxygen barrier coating through the use of different printing plate technologies and anilox rolls results in the best combination of roll and plate that can achieve comparable results to a pretreated, barrier film. Further knowledge of printing with an oxygen barrier coating inline produces results that benefit in the realm of cost and production.

Through a series of print runs testing different anilox rolls and plate technologies on a Mark Andy 2200 flexographic press, an oxygen barrier coating is applied to the film and then tested to compare how much oxygen can pass through the film.

Materials and Methods Materials and equipment used for the flexographic print run included a flexographic printing press, printing plates, oxygen barrier ink, anilox rolls, and a filmic substrate.

The printing press used for the press run was Cal Polyâ&#x20AC;&#x2122;s Mark Andy 2200 Flexographic Press. The first printing plate tested was a DuPont Cyrel DFQ plate. This plate acted as the control plate since there was no screening technology added. The second plate

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tested was a MacDermid Epic capped plate provided by MacDermid. The third plate was a DuPont Cyrel DFQ plate that was screened with cell-patterned technology using EskoArtworkâ&#x20AC;&#x2122;s plate cell patterning technology.

The specialty ink that was tested was SunBar 1.1 from SunChemical, one of the largest ink corporations nationwide. This two-part oxygen barrier coating prevents the penetration of certain gases that jeopardize the shelf life of a packaged product.

Three different anilox rolls were tested as the second variable introduced. The first was a 360 CPI, 6.53 BCM anilox roll. The second a 440 CPI, 3.33 BCM and the third anilox roll a 600 CPI 2.05 BCM. The filmic substrate evaluated was a 2 mil oriented Clear Polypropylene 5000 from Multi-Plastics Inc. It is critical that the film tested was non-heat sealable because that indicates the film is not pretreated with any coating. Other machinery that was used included an Oxygen Transmission Rate (OTR) Analyzer Model 8001 (Illinois Instruments).

The film was printed using the first anilox roll of 360 CPI, 6.53 BCM, to print the three plate technologies with the same specialty ink per run. A second print run was then performed to compare three different anilox rolls printing the same ink, using the capped plate. Once the film was treated with the barrier coating, it was separated into seven rolls and each roll then cut into two two-inch squares (4 inches 2). These squares were then placed in the OTR machine to see how much oxygen passed through the film.

Each film was measured at a sampling rate of 30 minutes.

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Chapter Four Results There were two print runs conducted on a Mark Andy 2200 Flexographic printing press. The first print run was comparing the effect of different plate technologies by printing with one conventional plate method and two plate-treatment technologies. One screening technology consisted of plate-cell patterning, while the second technology utilized the capped plate method.

A second print run was performed using the capped plate comparing the effect of different anilox rolls by printing with three rolls. The first roll had a cell count of 360 with a cell volume of 6.53 BCM and was the anilox roll used for the first print runs comparing the different plate technologies. The second anilox roll had a cell count of 440, and a volume of 3.33 BCM. The third roll used had the highest cell count of 600, with the lowest cell volume of 2.05 BCM. Using anilox rolls that increased in cell count and decreased in the cell volume allowed the comparison at lower ink coverages. Once the samples were printed, they were tested in an oxygen transmission rate machine to see which film had the lowest oxygen permeability. The film was separated into seven trolls: film with no treatment, film with control treatment (conventional plate), film with treatment 1 (plate cell patterned plate), film with treatment 2 (capped plate), film with anilox 1 (360 CPI, 6.53 BCM), film with anilox 2 (440 CPI, 3.33 BCM), and film with anilox 3 (600 CPI, 2.05 BCM). Each film was cut into two, 2-inch squares (4 inches2) to be placed in the Oxygen Transmission Rate (OTR) Analyzer Model 8001 (Illinois Instruments). The OTR was measured for each 2-inch square, per film, until it reached a final result and automatically stopped at 1% convergence with a bypass time of 30 minutes, and a sampling rate of 30 minutes. The temperature was 23째 C with RH at 0.0%. The results of the permeability for both tests run is found in Table 1 and Table 2.

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Oxygen Permeability

Plate

Mean

Oxygen Permeability

Test 1 (cm³/m²/24hrs) Test 2 (cm³/m²/24hrs)

(cm³/m²/24hrs)

Control (untreated)

896

938

917

Conventional

202

131

166.5

Plate Cell patterened

142

190

166

Capped

111

83.7

97.35

Table 1. Shows the average Oxygen Transmission Rate for each test of plate technology method used with anilox roll 360 CPI, 6.53 BCM.

Anilox Roll

Oxygen Permeability

Oxygen Permeability

Test 1 (cm³/m²/24hrs) Test 2 (cm³/m²/24hrs)

Mean

(cm³/m²/24hrs)

Film : Anilox 1 360 CPI 6.53 BCM

111

83.7

97.35

Film : Anilox 2 440 CPI 3.33 BCM

252

285

268.5

Film : Anilox 3 600 CPI 2.05BCM

333

370

351.5

Table 2. Shows the average Oxygen Transmission Rate for each test of anilox roll used with the capped plate technology.

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The results in Table 3 compare the averages of each film tested, to the oxygen permeability of the Mobile treated film already deposited with an oxygen barrier coating (pretreated film). This table shows a direct comparison of the different anilox rolls and screening technology to the pretreated film. These results reveal a significant difference between the untreated film and treated films, while the variation between the treated films and pretreated films varies greatly.

Mean

Plate

(cm³/m²/24hrs)

Control

917

Conventional Anilox 1

166.5

Plate Cell pattern Anilox 1

166

Capped Anilox 1

97.35

Anilox 1 360 CPI 6.53 BCM

97.35

Anilox 2 440 CPI 3.33 BCM

268.5

Anilox 3 600 CPI 2.05 BCM

351.5

Mobile (pretreated)

70

Table 3. Average oxygen transmission rate for each film compared to the pretreated film.

Anilox 1 represents the 360 CPI 6.53 BCM, and the Capped plate was used for the anilox tests.

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Chapter Five Conclusion The results concluded from this experiment provided beneficial information in terms of both cost and production efficiencies of specialty packaging and printing. As the data in Table 3 shows, coating the film with the barrier ink in general substantially lowered the oxygen transmission rate with a decrease from 917 OTR for the untreated film to 166.5 OTR for the conventional plate technology and anilox 1. The lack of increased barrier property for treatment 1 may be a result of how the plate cell treatment coating impacts ink uniformity. Further investigation is needed to determine why little substantial benefit occurred from the plate-cell patterned plate.

When compared, the results between the plate cell pattern and capped plates show another large reduction in oxygen permeability. While the plate cell patterned plate had an average OTR of 166, only 0.5 below the conventional plate, the capped plate had an OTR of 97.35. Both samples of the 2-inch squares from the capped plate had a much lower OTR than either of the squares tested from the plate cell pattern. When compared with the specifications of the permeability of the pretreated film, a 2.1 mil oriented polypropylene film with excellent oxygen barrier properties, the capped plate offers a competitive option with its average OTR slightly higher.

When the results from the use of different anilox rolls are compared, the permeability of the film decreases as the cell volume increases, resulting in greater ink-film thickness.

The first anilox roll used had the lowest cell count by almost half of what the third roll used, with a cell volume at over three times as high as the third roll used, resulting in an oxygen permeability almost four times lower. As the first anilox roll was also used to print the different screening technologies, it is highly likely that the screening technology

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results would have been higher had they been printed using either of the other anilox rolls tested.

Printing an oxygen barrier coating inline offers some unique benefits. The substrate cost is lower and similar results can be achieved using a more cost-effective coating method.

However, it is noted that it may be difficult to get the exact oxygen transmission rates achieved by other coating and extruding methods.

This study confirmed that with the right plate technology and anilox roll, similar oxygen barrier properties may be achieved in a more cost effective manner than purchasing pretreated films.

The results of the study concluded the best combination of plate technology and anilox roll to achieve optimum functionality of the barrier coating. The capped plate provided better barrier properties than the cell patterned plate with each anilox roll. The anilox roll that provided the best barrier property was the first anilox roll, 360 CPI, 6.53 BCM. As the cell count increased, and the cell volume decreased, the permeability of the coating increased dramatically between each anilox roll. In the case of printing with an oxygen barrier coating, the most functional combination of flexographic components includes capped plate technology with a 360 CPI, 6.53 BCM. In comparison to the pretreated film, this combination provides a competitive alternative that gives packaging companies the option of printing with barrier properties inline using a more cost and production efficient method.

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