TASTY WATER
Harry Brailey-Partridge DP 361 Product Development
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Con tent s 2-3. 4-5. 6-9. 10-13. 14-17. 18-19. 20-23. 24-25. 26-27 28-29 30-31 32-33 36-39 40-43 44-47 48-49 50 51 52-55 56-59 60-61 62-63 66-67 68 69 70-73 74-77 78-81 82
Contents Product Poster Project Planning Product Design Specification (PDS) Fruit Taste Test Concept Sketches Silicone Prototyping 3D Printed Mould Design Zcorp Moulding Failure Mode Effect Analysis (FMEA) Silicone Hardness Testing Sharing Knowledge Bubble Bottle Prototype Mechanism Development Split Prototype Human Factors Task Analysis Persona User Testing: Crushing User Testing: Drinking Function Use Desire Laser Scanning Design for Manufacture Design for Assembly Costing Product Schematic Technical Drawings Evaluation Vs PDS References
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TASTY WATER
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Project Planning Project Plan Task
Duration
Start
Finsh
Product Development
46.9 Days
20/01/14
25/03/14
Mechanism Concepts
6.5 Days
20/01/14
28/01/14
Research Infuser Mechanisms
1 Day
20/01/14
20/01/14
Buy + Hack Existing Products into Models
3 Days
21/01/14
23/01/14
Test Hacked Mechanisms
2 Days
24/01/14
27/01/14
Evaluate Mechanism
0.5 Days
28/01/14
28/01/14
Mechanism Development
7.5 Days
28/01/14
06/02/14
Select Mechanism
0.5 Days
28/01/14
28/01/14
Design Mechanism
2 Days
29/01/14
30/01/14
Test Mechanism
2 Days
31/01/14
03/02/14
Evaluate Mechanism Fix Issues with Mechanism
0.5 Days 3 Days
04/02/14 04/02/14
04/02/14 06/02/14
9 Days
07/02/14
19/02/14
3 Days 2 Days
07/02/14 12/02/14
11/02/14 13/02/14
2 Days
14/02/14
17/02/14
2 Days
18/02/14
19/02/14
21.5 Days
29/01/14
27/02/14
Research Bottle Design Buy + Hack Existing Products into Bottles
2 Days 3 Days
29/01/14 20/02/14
30/01/14 24/02/14
Test Hack Prototypes
2 Days
25/02/14
26/02/14
Evaluate Hack Mechanisms
0.5 Days
27/02/14
27/02/14
Bottle Development
8.5 Days
27/02/14
11/03/14
Select Bottle Design
0.5 Days 3 Days
27/02/14 28/02/14
27/02/14 04/03/14
2 Days
05/03/14
06/03/14
0.5 Days 3 Days
07/03/14 07/03/14
07/03/14 11/03/14
Mechanism Development 2 Develop Mechanism Test Mechanism Evaluate Mechanism Design Fix Issues with Mechanism
Bottle Concepts
Design Bottle Test bottle Evaluate Bottle Fix issues with bottle
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...20th January
y
Sheet 1 February
March
7
Project Planning Project Plan Task
Duration
Start
Finsh
Bottle Development 2
8 Days
12/03/14
21/03/04
Develop Bottle
2 Days
12/03/14
13/03/14
Test Bottle Design
2 Days
14/03/14
17/03/14
Evaulate Bottle Design
2 Days
18/03/14
19/03/14
Fix Issues with Bottle Design
2 Days
20/03/14
21/03/14
...12th M
...20th Ja 46.9 Days
20/01/14
25/03/14
PDS
0.5 Days
20/01/14
20/01/14
2D Part Drawing 2D Assembly Exploded + Collapsed Assemblies Validation & Varification
0.4 Days 0.2 Days 0.3 Days
24/03/14 24/03/14 24/03/14
24/03/14 24/03/14 24/03/14
1 Day
24/03/14
25/03/14
Specific Tasks
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Sheet 2
th March
th January
February
March
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PDS Performance Requirements 1. Function a. The product must contain ≤ 1 Litre of water b. The product must crush fruit internally, taking no longer than 30 seconds for any small indehiscent fruits (i.e Strawberry, Raspberry, Blackcurrant, and Cherry) c. The product must provide 1 portion of fruit to the user over the period of one use. (80g Dry weight of fruit = 1 portion) d. The Product must filter all contaminants greater than 1 mm out of the solution once the fruit has been macerated. (Size of small seeds) 2. Appearance a. The product must suit current trends in the kitchen gadget and homeware sector. It should appear: 1. Simple to use 2. Fun 3. Novel / Interesting b. The product must be appealing to 18-24 years olds. (Appearance will be assessed using a focus group and Likert scale with ratings from 1-5) 3. Reliability a. The product must be drip and spill proof to BS EN 1779:1999 (Non – Destructive leak testing) using BS EN 1593:1999 Non-Destructive Testing. Leak testing. Bubble Emission Techniques. b. The product must be chemical and UV resistant to BS 2782- 0:2011 Methods of testing plastic, BS ISO 4665:2006 Rubber, Vulcanized or Thermoplastic. Resistance to weathering. c. Product must withstand compression force of 800N (adult human male) 4. Environment a. The product must be UV resistant to BS EN ISO 4892-1 Plastics – Methods of exposure to laboratory light sources. b. Product must be resistant to cleaning methods and solutions (BS ISO 29664:2010 Plastics. Artificial weathering including acidic deposition.) c. Product must be resistant to moisture and damp (BS EN ISO 4611:2010 Plastics. Determination of the effects of exposure to damp heat, water spray and salt mist) d. Product must be able to operate between -20oc and +60oc 5. Production Cost a. Bottle Cost: The silicone part of the bottle will cost no more than £2 to produce b. Mechanism Cost: All parts of the mechanism will have a combined cost of >£3 c. Packaging Cost; The cost of packaging materials will be no more then £3 d. Complete Product Cost: The combined cost of the bottle will be no more then £8 6. Ergonomics a. Product mechanism must be comfortable to use b. Drinking motion should be comfortable c. Product should have a high friction coefficient when wet to enable better grip. (Ergonomics will be assessed using a focus group and Likert scale with ratings from 1-5) 7. Quality a. The product must be dishwasher safe to BS EN 12875-1:2005, product should last for at least 3 test cycles to BS EN 12875. (150+2x250) Mechanical dishwashing resistance of utensils. b. Product must not fail through regular use (5 Uses a week) within 2 years (480 uses) 8. Weight a. Bottle weight ≤300g b. Mechanism weight ≤200g 10
Manufacture Requirements 1. Process a. All components to be of metric form and comply with BS 3734-1:1997 and ISO 3302-1:1996 Rubber - Tolerances for products 2. Materials a. Materials used in contact with fruit/water must be food safe to EC 1935/2004 Food Contact Materials and BS EN 1186-1:2002 Materials and articles in contact with foodstuffs. b. Surfaces in contact with foodstuffs must not contain BPA/phthalates as per FSA Policy and Advice (http://www.food.gov.uk/policy-advice/#.UydtSPl_uuI) c. Plastics used in the product will be marked in accordance with BS EN ISO 11469:2000 Plastics. Generic Identification and marking of plastic products. 3. Assembly a. Assembly of mechanism should take no more than 20 seconds by a semi-skilled worker. b. Assembly of all components should take no longer than 40 seconds. c. Products will use standardised fitting where possible. d. Product will be assembled by hand. 4. Packing a. Packaging should weigh no more than half the weight of the completed product (250g) b. Product must use recycled packing materials that conform to 94/62/EC Packaging and packaging waste. c. Product should tessellate to fit in high volume on a standardised shipping pallet in a Series 1 Freight Container to BS ISO 668:2013 standards. 5. Quality a. All materials will be tested to quality assurance standards for plastics, metals and/ or, composites. BS ISO 34-1:2010 Rubber, Vulcanized or thermoplastic – determination of tear strength and BS ISO 5893:2002 Rubber and plastics test equipment - tensile, flexural and compression types. b. All processes used in the manufacture of the product will be assessed to BS EN ISO 9000:2005 Quality Management Systems (ISO 9001 pending revision in 2015) c. 10% of products will be tested to ensure quality is maintained d. All tests will be conducted by a laboratory certified to BS EN ISO/IEC 17025:2005 General requirements for the competence of testing and calibration laboratories. 6. Delivery Date a. The product will be developed in order for a concept to be pitched to potential investors at a design exhibition on the 26th May 2014.
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PDS Operation Requirements 1. Installation a. The product will come packaged will all devices needed to meet PDA point 1i) Function 2. Use
a. User unscrews the product’s lid b. User places 80g of fresh fruit inside the product c. User fills the bottle to a quarter full with the desired liquid d. User expels air from the product and screws the lid down e. User crushes the fruit using the textured surface on the inside of the bottle (roll/squeeze/etc) f. User opens bottle and fills it with the required amount of the desired liquid g. User opens the bottle and drinks until it is empty h. To clean the device, the user opens the bottle and pushes the base through the neck, reversing the product. i. The user then wipes down the interior with warm water and soap. j. Product is rinsed and left to dry k. Once the product is dry the user pushes the base back through the neck, returning it to its original shape. 3. Maintenance a. The product should take no longer than 2 minutes to clean b. All parts on the product should be detailed in the instruction manual as well as how to disassemble and clean them. c. The product must dry thoroughly to prevent mould and damp causing damage to the product. d. All blades and consumables will be removable and replaceable. e. Replacement parts will be available from the company so that in the event of any of them becoming damaged, they can be replaced. 4. Safety a. The product must not, in its intended use cause harm to the user b. Cleaning and maintenance must not cause hard to the user c. The product must have no sharp edges d. Product must not have any parts that may become detached and could cause harm to the user.
Acceptance Standards 1. Inspection a. The product will be inspected after each part is produced in order to ensure all parts progressing to assembly are of sufficient quality and reliability. b. 10% of product will be tested after assembly c. 10-20% of products will be tested after packaging d. All inspections will be carried out by trained individuals to BS EN ISO 9000:2005 Quality Management Systems 2. Testing a. Test will where possible revert to using BSi standards for each type of test i.e Puncture/leak test to BS EN 1593:1999 Non-Destructive Testing. Leak testing. Bubble Emission Techniques. b. Compression/flexion to BS ISO 5893:2002 Rubber and plastics test equipment - tensile, flexural and compression types. 3. Patents a. The product must not infringe on any other’s intellectual property b. The product will where necessary licence technologies from other patent holders in the event of using their components in the product 12
c. Any new materials/technologies/processes developed during the creation of this product will be patented should they occur. i) Competitors’ Patents The following patents should be taken into account when designing and making the product to ensure that no intellectual property rights are breached:
1. 2. 3. 4. 5. 6.
Beverage flavouring applicator US 8522968 B2 Drink mix apparatus for making personal quantities of beverage US 6372270 B1 Multi-Chambered drink bottle US 20060021996 A1 Silicone Resin Container US 20130256310 A1 Collapsible containers with exchangeable liners US 20060182372 A1 Receptacle with deformable flexible wall, of the bottle, pouch or tube type US 5484083 A
Disposal Requirements 1. Standards a. Product should be disposed of and recycled to Eu standard 94/62/EC Packaging and packaging waste. 2. Legislation a. Product will be disposed of by user in accordance to laws in their country of residence. b. Product/waste materials from production will be disposed of by manufacturer or industrial partner in accordance with laws in which the product is produced/assembled/sold. 3. Company Policy a. The product should use <75% recycled material in its packaging b. The product must in its intended production/use/disposal not cause damage to the environment. c. Materials will be marked to BS/Eu standards for recycling of plastic products. Directive 2008/98/EC Waste Framework Directive and Council Directive 99/31/EC for the Landfill of Waste 4. Hazards a. Product should not decompose to form dangerous chemicals/compounds
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Fruit Taste Testing The first taste tests were carried out to determine the best kinds of fruit for use in the bottle and the most effective ways to disperse the juice within the water. This round of testing used strawberries, raspberries, cherries, blueberries and blackberries as these fruits are small in size so are easy to place within the container whilst also having high amounts of vitamin C and pleasant taste. The three methods of dispersion used in this experiment were: Method 1: Cutting the Fruit in Half and placing into beaker Method 2: Dicing the pieces into 4mm2 pieces placing into beaker Method 3: Mashing fruit in the beaker
In each instance of the test the same amount of fruit and volume of water were used to ensure that the only variable effecting the taste of the drink was the dispersion method used. The prepared solutions where then given to a participant who was asked to rank the flavours in order of best to worst taste. The test proved method 3 to be the most effective way to imparting flavour into the water. This is because the structure of the fruit is more broken up by mashing than when cut with a knife. The mashing motion also helps to stir the solution to ensure the flavour fully circulates in the drink. After completing and analysing the experiment it was clear that the product should use a press or mashing type motion as its method of dispersing juice within the water. 14
Design Consideration Out of the 5 types of fruit used, only strawberry, raspberry and blackberry produced an effective flavour. Therefore further testing should be carried out into sour and citrus fruits as they are usually similar in structure to berries.
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The second fruit taste test was carried out to evaluate the flavour produced by using a wider range of fruit. In this experiment only two conditions where used, finely diced or cubed. As strawberry had created a good flavour in the first experiment it was chosen again for as a control flavour to judge the strength of others against, In this experiment the fruits which produced effective flavours were the lemon, lime and orange. Kiwi and Mango failed to create effective flavours potentially due to the high water content in the flesh of the fruit diluting the taste.
However these experiments were conducted using one type of fruit from one source. This makes it hard to generalise the results to taste that other user will create. Design consideration: Although citrus fruits produce a strong flavour they have a far longer, more involved preparation process in order to create the same strength of taste as berries. Therefore in order to create an efficient and satisfying product berries should be the main type of fruit the product is intended to be used with.
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Silicone Prototyping 21
First Silicone Casts After researching the strength of flavour, best dispersal methods and some similar pre-existing products the next stage was to decide how the bottle would mash the fruit. It quickly became clear that the product would have to have moving parts in order to mash the fruit however moving mechanisms can be hard to clean and would likely become clogged. To eliminate the use of a mechanism, Massa has a textured silicone rubber for the body of the bottle, this allows the bottle to be reversed for when it is cleaned.
To test if silicone could effectively mash fruit, samples of textured wall sections large enough to place a piece of fruit in were created. These enabled the investigation of how texture effected the quality of mashed fruit and demonstrated that silicone could crush fruit. However the excessive height of the textures created a new series of issues for product use and cleaning.
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Design Consideration: There is no reason to have high textures, they are cumbersome and cost more to manufacture due to the extra material required. A smaller texture using a deformed surface rather than a patterned feature would provide enough friction to grab and grind fruit but be smooth enough to allow the product to be flexible for easier grinding and inversion. Changing from a patterned feature on a surface to a deformed surface can reduce the total volume of silicone needed to produce the part by 35-40% depending on the size of the features and the depth of the surface deform. 23
3D Printed Mould Design After making the decision to use a deformed surface to create the texture in the model it became apparent that the only way to create a mould precisely and accurately enough would be to 3D print it. The first casting attempt was a proof of concept model created to learn if and how silicone could be moulded from a powder based 3D printer. The inner core of this initial design was destroyed when removing from the printer due to an overestimation of the powder’s strength and poor placement of drainage holes to remove powder from the inside of the printed part.
The second design for the inner core of the mould was improved in 4 different ways. Firstly it uses a 2mm thicker wall then the original design. Secondly ribs have been added to increase the structural integrity of the mould core and to create a more robust part to prevent breakages from parts being handle. The third improvement in the design is the 12mm metal studding used to secure the part inside the mould, this increases the stability of the inner core and chances of creating a correctly aligned cast. The final improvement in the design is to print it in two halves. This enables the part to be undercut when being excavated to ensure that the part always comes out without breaking.
Fault 1
Fault 2
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Zcorp Molding The silicone that was chosen for use in the first prototype was SORTA-Clear 18A, an addition cure silicone with high tensile strength (425 PSI to ASTM D-412) and a very low mixed viscosity. This ensures that the silicone will flow correctly and fully coat both surfaces of the mould. The mould was sprayed with a coat of Mann ease release 200 and the silicone was degassed in order to reduce the chance of a failed moulding.
After allowing time for the silicone to cure, the part extraction process began. A chisel was inserted into the split line between the two mould boxes to try to pry them apart. However this only caused damage to the surface of the mould by crumbling away the layers of 3D printed powder that were not fully saturated with resin. After trying for some time to carefully pry the mould apart, the decision was made to break down the outer mould box in order to retrieve the silicone part and the inner core of the mould. 26
Design Consideration: The resined powder creates a high quality surface that is relatively easy to work with so is exceptionally useful when working with silicone. However experimentation on a range of mould release agents should be carried out before next casting to ensure part can be more easily extracted from the mould. 27
FMEA Failure Mode Effect Analysis (FMEA) is used as a method of trying to discover faults with a product in order for them to be removed in the next design iteration.
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Silicone Hardness Testing A wide range of silicone parts have been produced to act as surface samples throughout the earlier stages of the project. These samples could be measured to help choose the specific grade of silicone for use in the final prototype as there was a huge variation in the hardness of the parts. These differences would have been caused by errors in the production of the silicone have proven useful for demonstrating the differences that hardness and texture have on the feel of a part. In this experiment each material sample is measured in 3 different places and an average for the silicone hardness is created. All measurements were carried out using a calibrated Shore A scale Durometer.
Material Sample 3mm Flat Sheet 3mm Flat sheet circle extrudes 3mm Flat sheet square extrudes 3mm Flat sheet rectangle extrude 6mm Flat sheet Textured Silicone Heat Mat First bottle prototype Green Accordian (Softer) bottle PET Drinks Bottle
Result 1 19 19 11 17 15 41 9 60 73
Result 2 15.5 16 9 14 11 44 6 65 82
Result 3 18 18 6.5 7 12 38 13 90 68
Average 17.5 17.6 8.83 12.6 12.6 41 9.33 71.6 74.3
Type of Silicone SORTA Clear 18A SORTA Clear 18A SORTA Clear 18A SORTA Clear 18A SORTA Clear 18A Brought in Product SORTA Clear 18A Brought in Product Brought in Product
The results of the testing show that the average silicone hardness is Shore 13A, 5 Shore grades lower then what the silicone should have been if mixed correctly. This was due to human error in mixing the silicone and a calibration error in the scales used to measure the different components of the silicone. After researching different grades of silicone the type i will be using in my final prototype will have a Shore hardness of 40 as this gives enough flex to allow the material to be manipulated but should still provide enough structure for the bottle to be able to stand on its base. 30
Sharing Knowledge At the start of the project very little was known about silicone moulding within the university and no-one had ever tried 3D printing a silicone mould. This meant that thought out the course of the project many of the methodologies and techniques used in the making of the parts had to be invented. In order to ensure that this knowledge was not wasted it was recorded via film and photo and used in the creation of a 3D printing and Model making blog. The blog covered a range of topics from the basics of 3D printing and silicone casting to video guides detailing part removal from specific machines. A blog format was chosen for this set of guides as they are easy to navigate, familiar to the intended audience and provide impetus to regularly visit in order to check for updates and news related to the subject. http://hbrailey.wix.com/100microns
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Bubble Bottle Prototype After conducting the experiments required to prove the concept behind my product, the next stage of the project was the creation of full scale prototypes with which to conduct user testing. The goal of the first full scale prototype were to discover more about the creation of multi core 3D printed moulds. The two key things that needed to be understood where, can a textured surface be successful when applied to the inner core of a mould and what is the best way to align an inner core to ensure that the part remains properly centred during the casting process.
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The first full scale prototype had two casting defects. Firstly trapped pockets of air within the mould caused bubbles in the part and secondly the mould was not filled completely, this lead to a weaker top section which broke during the demolding process and had to be removed.
Design Considerations: During the process of pouring the mould a large amount of air can become trapped inside the silicone. In order to reduce the amount of air introduced to the silicone it should be de-gassed in the two outer mould pieces. Degassing inside the mould reduces the amount of air that will be in the final cast part as it removes the need to pour the silicone once it has been processed. 39
Mechanism Development After creating the first successful prototype for the product the next task was to ensure that it could be securely closed in a way that would still allow the product to be completely disassembled for cleaning and recycling. In order to create a usable product the mechanism would have to be simple to remove from the product, taking no longer than 20 seconds to separate the silicone body of the bottle from all other components. Creating a metric for disassembly focuses the designer on the efficiency of the product and further increases the desirability of the completed design. The second criteria that the mechanism must meet relates to user satisfaction. There are many drinks products on the market that juice fruit and a high proportion of these offer versions with and without pulp based on user preference. To ensure that the product is desirable to the greatest number of potential users it should allow the user to make their own decision on the content of their drink.
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The first type of closing mechanism develope was based on garden hose connector as they are incredibly easy to understand and simple to remove. However in order to have a filter mounted in this type of mechanism the design would need to have requires the use of multiple small parts. Not only are smaller parts hard to use they are also easy to loose or break and may if incorrectly fastened be a choking hazard. Design Consideration Screw threads add bulk to a design and can negitivly impact the aesthetics of the product if placed in highly visable locations as would be the case in this design. In order to produce a more desirable product the design must use a different method of fastening.
Development sketching for first mechanism concept.
3 Part closing mechanism based on hose connector.
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Mechanism Development The second iteration of the mechanism uses another kind of hose fastening. The jubilee clip provides a much stronger join then the original design with a greatly reduced visual profile however the metal edges of the clip may cause damage to the silicone over time with frequent use. The greatest flaw with this type of locking mechanism is the need for a tool in order to open and close the device.
Design Consideration: The jubilee clip creates a much more secure fastening mechanism then the hose connector device but the need for a tool eliminates this mechanism from consideration as a solution. The perfect type of fastening mechanism would allow the user the same strength of connection as the jubalee clip but provide a tool free solution. 42
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Split Prototype After creating the first prototype the mould was refined in order to reduce the number of bubbles and ensure a more reliable cast.
The second refinement was a more secure way of fastening the inner cores to the outer cores of the mould, this reduced the likelihood of the mould core being incorrectly placed and causing potential failure in the cast.
The first refinement to the mould was a new method of clamping the two outer mould cores together, this reduced the amount of material seeping that spilled out of the mould and ensured a more even force was applied across the whole surface of the mould.
Using lessons learned in the creation the first prototype the second silicone body was then cast.
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Split Prototype After 18 hours curing in the mould the part was ready to be removed. However as this part was produced without defects and better filled the mould, the neck of the bottle was far narrower then the first prototype. This made the part harder to extract from the mould and caused it to rupture from the neck down the left side of the bottle. The bottle was then repaired with a silicone sealant using the mould as a former to ensure the correct shape. Design Considerations: In order to remove the part from the mould the silicone has to be able to expand without rupturing.
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The elongation at break of the silione used was 400% (ISO 37/ASTM D-412) however this test will be conducted using a perfect Shore A 40 grade silicone which will be different to the silicone mixed for the bottle due to the errors described in the silicone testing section. As it will be difficult to ensure a perfect mix, the material properties listed on the data sheet should be used as a guide and the ratio of the size of the bottle at the neck to the size of the bottle at the base should be no more then 1:3. This will ensure the part can be removed from the mould after casting.
Human Factors Once a working prototype has been created the prototype must be thoroughly tested to validate is usability. Based on the results of prior testing and questions commonly asked about the product two clear usability concerns have been raised. -How much effort is required to create the fruit infused drink and will this dissuade potential consumers? - How will users drink from a soft bottle and how might this type of bottle impact the drinking experience?
The context in which a product is used can dramatically alter the ease of operating the product. Therefore it important to understand as much as possible about how the product will be used. Primary User: Health conscious young adults 18-24 years old. Tasks: Crushing fruit, drinking from the bottle. Equipment: The bottle, water, fruit. Physical Environment: The product is small enough to fit in almost any bag, especially when shrunk so will be used indoors and out. Churching will more than likely take place in the user’s home prior to leaving the house. Social Environment: Western cultures place high value on the possessions a person owns and the product demonstrates the user’s commitment to a healthier lifestyle.
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Task Analysis 1. User unscrews the product’s lid
7. User opens the bottle and drinks until it is empty
2. User places 80g of fresh fruit inside the product
8. To clean the device, the user opens the bottle and pushes the base through the neck, reversing the product.
3. User fills the bottle to a quarter full with the desired liquid
9. The user then wipes down the interior with warm water and soap.
4. User expels air from the product and screws the lid down 5. User crushes the fruit using the textured surface on the inside of the bottle (roll/squeeze/etc) 6. User opens bottle and fills it with the required amount of the desired liquid
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10. Product is rinsed and left to dry 11. Once the product is dry the user pushes the base back through the neck, returning it to its original shape.
Persona James Thompson James is a 19 year old chemistry student at York University. He has just finished school and is now experiencing living life for the first time without his parents to help with day to day tasks. He has cooked some basic meals whilst at home but most of his food has been prepared by Sarah, his mother. James shares his house at university with his 3 male housemates and the kitchen is often unkempt and dirty. A typical meal for James is an oven pizza and chips as it is relatively cheap; quick to cook, easy to portion and there is very little waste to deal with. James realises he doesn’t each enough fruit and vegetables and because of this, often buys them in the supermarket. However he often opts for quicker options at mealtimes and most weeks around half of his fresh fruit and vegetables spoil. He wishes he could have some way to remind himself to eat more of his fruit and veg before it goes bad.
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User Testing: Crushing Participants: 6 Students (3 Male, 3 Female) aged between 19 and 23 Task: Crush one portion (80g) of berries using the product Scenario: You are just about to leave the house to go to an early morning lecture, you decide to take your new water bottle with you. Use the product to crush a portion of fruit to make your drink with. Metrics: Effectiveness - Size of pieces of fruit created. Efficiency - Time taken to crush fruit. Satisfaction - How did using the product make you feel? 53
User Testing: Crushing In order to understand the results of user testing the three measures used to assess usability are considered.
Efficiency - The average time take for each participant to crush the fruit using the bottle was 43 seconds. The time taken to crush the fruit depended on the crushing method used, with the participants who rolled the product on the table taking the least time and those choosing to use the product without a surface taking the longest.
Effectiveness- Size of crushed strawberries ranged from a fine pulp to larger 30mm pieces, demonstrating that the produce can crush fruit. The size of the largest pieces of fruit depended on the user, with males tending to exhaustively grind the fruit and females using a more delicate approach.
Satisfaction - The main concern raised in this part of user testing was the width of the bottle as this caused issues for holding and manipulating the bottle in participants with smaller hand sizes.
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Evaluation
Efficiency - Participants who used a surface to aid in crushing the fruit took far less time than those who held the product whilst they crushed the fruit. However the miniscule time difference between the fastest and slowest times remove this from concern.
Effectiveness - The fruit samples with larger individual strawberries tended to be the ones left uncrushed at the end of the experiment. In this experiment this was due to the temperature of the fruit as this can affect the ease of which it can be crushed. Larger chilled or even semi frozen pieces removed from a fridge will reduce the effectiveness of the product and should be stressed to the user in product literature.
Satisfaction - The key piece of information gained through this stage of testing. The width and depth of the product stopped users from being able to properly grasp the product when filling it with fruit. The next redesign must account for this by either reducing in size or being more suited to freestanding on the table. 55
User Testing: Drinking Participants: 6 Students (3 Male, 3 Female) aged between 19 and 23 Task: Drink from the bottle. Scenario: You have now arrived at your lecture and decide to sit down and take a drink. Metrics: Effectiveness - Number of errors incurred whilst drinking from bottle. Efficiency - How did you decide how to drink from the bottle? Satisfaction - How did drinking from bottle make you feel? 56
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Human Factors:Drinking The second human factors test focussed on the motion of drinking from the bottle as this concern has been raised before, including during testing of product samples.
Evaluation Effectiveness - 4 out of 6 participants failed to drink correctly from the bottle first time. This was most likely due to the flat lip which acts as a prompt to the users and informs them to drink as they would from any other container. The final design should make use of affordance to ensure that users instinctively know which direction to drink from.
Effectiveness - 2 out of 6 participants drank correctly from the bottle the first time and 1 participant failed to drink correctly at all. The remaining 3 scored an average of 1 error each.
Efficiency - Participants may have taken the product placement on the desk at the start of the test as a que for which direction to drink from the bottle. In future tests of drinking motion the product will be laid flat on the table or even placed in its disassembled state in order to encourage users to make their own decisions on how to use the product.
Efficiency - Most participants reported they “just picked it up (from the table)” and drank from it in whichever direction it was facing. However of the 3 who scored errors 2 participants reported that drinking incorrectly felt wrong and stated this as the reason for their change in drinking position Satisfaction - 3 of the 6 participants reported enjoying drinking from the bottle. Of the remaining 3 participants, 2 stated the shape of the bottle made it harder to drink and the last commented that drinking from the bottle made them feel self-conscious due to the size and drinking position.
Satisfaction - Of the 2 users who drank without error the first time, only one reported enjoying drinking from the bottle. The other stated that due to the shape of the bottle the angle at which water would come out of the bottle caused (pain) overextension of the neck and all of the water to suddenly come out rapidly. This concept could be used in my bottle as a method of ensuring that the user drinks in the intended way. This would be achieved by placing the cap at an angle to the base of the product, this would increase the extension of the neck needed to drink the bottle to the point where the user would simply rotate the bottle.
Incorrect drinking motion casues water to sink to lowest point in bottle
Correct drinking motion requires almost no extension of the neck as water it not retained in the product
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Function Use Desire Jordan, 2000 states that in order for a product to be successful in mass market it must be 3 things: Functional The product has been designed to complete a specific task or purpose Useable Features of the product must be designed so the user can achieve their specific goals with effectiveness, efficiency and satisfaction Desirable The product connects with users on an emotional level 60
To ensure the product has mass market appeal Jordan’s 3 factors have been included within the product. Functional The product has been designed to crush fruit in order to make a drink. Useable The product has been designed with crushing and washing as key goal throughout the project. The locking mechanism will take less than 20 seconds to completely remove from the product and the bottle has been designed to reduce the need for excessive overextension of wrist or neck. Desirable The product is novel and innovative, this allows the user to be the first person in their social group to own the new product. Due to the low cost of the silicone body of the bottle (£2.16) and the ease of colouring silicone the user will have their choice of a vast range of a different, customized products with which the user can show their self-image and personal values. 61
Final Prototype Carving With new design considerations from user testing the final prototype started to take shape.
Consideration 1: Size of the bottle Many of the people who have held the previous prototype mentioned that it was too large for their hands. This concern was also mentioned during the user testing conducted on crushing and drinking using the bottle.
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Consideration 2: Angle of cap By increasing the angle the cap sits on the neck of the bottle the product increases the chance of the user drinking the product in the correct way.
Consideration 3: Ratio of neck to base In order to ensure that the silicone part can be removed from the mould the ratio of bottle neck to base should be less than 3:1.
The first step in the process was to sketch the design onto a block of foam from which to carve the final prototype. This method was chosen as it allows the designer to have greatest possible level of control over the form of the model The model was initally roughed out with a coping saw and knife. Once the rough shape of the bottle had taken shape sandpaper was used to slowly remove material intill the desired shape was completed. 63
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Laser Scanning After creating the foam prototype it was necessary to digitize it using the 3D scanner as this would take far less time and be to a greater level of accuracy then measuring and CAD modelling the shape from scratch. The scanned bottle was then taken into Solidworks, and analysed with the curvature tool to check the quality of the part. Once the scanned model is there for reference then it is simply a case of adding in the sketch planes and creating the part using either surface or solid modelling tools. Finally once the designer is happy with the part they have built the scan can be supressed, hidden or deleted and the rest of the CAD model can be finished. 65
Design for Manufacture In order to calculate if a product is market viable, all potential costs must be identified and reduced to create the cheepest possible product and generate the greatest profit. Here the general design considerations for the product, followed by the specific injection moulding considerations for the silicone body of the product.
General Considerations Reduce Part Count Any Reduction in part count would create over moulded parts which cannot be recycled at the product’s end of life.
Surface Finish Selection Matt Smooth outside. Surface displacement 0.5 baseline -1mm on inside of part.
Modularise Multiple Parts
Lead Time
There are no duplicate parts in this design.
20 Days to 4 depending on geometry.
weeks part
Use Standardised Parts Yes, Filter disc as part can already be cheaply purchased. Access to Fastenings All parts of the design can be disasembled and removed, except for the locking pin mechanism as this part will be under higher forces (torque when tightening/loosening neck clamp).
Quantity of Moving Parts 6. Must Parts be Difference Materials? Yes, to allow for cleaning. Will Servicing be Effected? Yes, servicing will become infinitely easier.
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Injection Moulding Considerations Material Name:
Warping
Xiameter Brand LSR Shore 40A (FDA food regulation 21 CFR 177.2600 compliant).
Part allowed to cool at holding pressure to prevent expansion.
Mould Direction
Holding Pressure
Straight pull with 1 inner core.
Required to stop expansion of silicone rather than shrinkage (as in thermoplastics) 50-200 bar.
Mould Size Type of Gate
One product per mould cycle.
Sub Gate Mould Materials (DIN Steel Specifications) Retainer Plate DIN C45 W
Cure at Gate
Moulding Plate DIN 40 CrMnMoS 8 6
1-4 Seconds until silicone is cured at gate and cannot flow back.
Moulding Platens DIN X38 CrMoV 5 1
Parting Lines
Injection Pressure
Dependent on cost and expertise of tool design.
Dependent on the geometry of the runner >400 bar.
Runner System
Required Heat Energy
Cold.
50W/kg.
Shrinkage
Fill Amount
2.5-3% after de-moulding and cooling processes.
Precisely 98-99% of total cavity to allow for part expansion during heating.
De-moulding System Filling Time
Air Eject, however parts at the beginning of production run may stick to tool. Ease of de-moulding increases after some cycles.
0.5-3 Seconds.
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Design for Assembly Design for Assembly Checklist Parts are inserted from the top of the assembly: Yes Parts are self-aligning: Yes Parts do not need to be oriented: No, 2/6 require alignment Parts require only one hand for assembly: All parts require two hands Parts require no tools: No parts require tools Parts is assembled in a single, linear motion: Yes Parts is secured immediately upon insertion: Yes Consider customer assembly: The product has been designed in order to be easy to assemble and disasemble for the user to clean. There are no steps in the assembly of the product that a layperson couldn’t understand.
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Costings Mould and Material Cost Once the product has been audited using DFM guidelines enough information is known to work out the cost of each of the different processes required to make the product. Compontent Bottle Body Bottle Cap Mounting Tube Locking Assembly Filter Housing Filter Total
Material Xiameter LSR PET PET Stainless Steel PET Titanum
Quantity 10,000 10,000 10,000 10,000 10,000 10,000 N/A
Process Injection Moulded Injection Moulded Injection Moulded Die Cut Injection Moulded Brought in Component
Unit Cost £2.16 £0.26 £0.53 £0.09 £0.14 £0.01 £3.19
Mould Cost £25,932.78 £10,358.72 £9,581.8 £2,502.4 £9,056.51 Brought in Component £57,432.21
Assembly Cost After calculating the cost of the tools to make the product and the material cost the last stage is to work out the cost of product assembly. All parts of the product assembly by hand with no tools required Compontent
Material
Quantity
Bottle Body Bottle Cap Mounting Tube Locking Assembly Filter Housing Filter Total
Xiameter LSR PET PET Stainless Steel PET Titanum
1 1 1 1 1 1
Handling time
Insertion time
Total Time
Cost
(s) 2.55 1.25 1 2 1.75 3
(s) 6 3 2 4 3 4
(s) 8.55 4.25 3 6 4.75 7 33.55
(£) 0.0095 0.0047 0.0033 0.0066 0.0052 0.0077 £0.037
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Product Schematic Imbue Key Features: Textured Inner surface for crushing fruit Reversible for cleaning Choice of filter depending on user preference Low Production cost £3.21 Massive customisability and chance for add on products, such as a carbon filter attachment instead of the filter for purified water. BPA Free Phthalate Free
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Surface Analysis These two images below show the qualities of the surfaces that have been used in the model. The Curvature analysis shows the main body of the bottle is well modelled and has reasonable curvature. The red lines around the top cap show the curvature here is very steep, this is because the part is built as a solid and corners are filleted rather then split. The zebra stipe shows how the surfaces connect to each other in a more visual way.
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Product Schematic
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The Mechanism In order to open the bottle the user has to unlock the pin by sliding it upwards over the cap until its free of obstruction. The locking pin is then twisted, loosening the clamp on the top of the bottle until. The pin is then removed and the bottle cap twists off, this allows the mounting tube to be removed from the neck of the bottle. Next the filter is removed by unhooking the clips on the base of the filter housing. The filter housing can then be removed by twisting it off of the mounting tube. Finally the user is left with the silicone bottle body which can then be cleaned or filled depending on product use. 73
A
B
DRAWING NUMBER 4.3
C
D
2.45
1
90
2 3
82
42
4 5
39
3
175
212
6 7 8 A
None
COPY MODIFICATION
20/05/2014
DATE
H.B
DR'N
A.G 23/05/2014 GENERAL DIMENSIONAL TO
CH'D
AP'D
THIRD ANGLE PROJECTION UNIVERSITY OF BRIGHTON SCHOOL OF COMPUTING ENGINEERING & MATHEMATICS
MACHINED LINEAR TOL. UNMACHINED LINEAR TOL. OTHER TOLERANCES STATED MACHINING SHOWN THUS REMOVE SEAM LINES SEE DRAWING NUMBER
E
H
G
F
1 2 3 10
4 5
205
6 7 DIMENSIONS, CURVATURE AND TEXTURE AS PER CAD MODEL SUPPLIED 212MM/82MM/90MM HxWxD
TOLS .
OL. ATED US
0.25 0.00 0.25
MATERIAL TYPE Shore 40A Silicone
MATERIAL FORM INJECTION MOULDED
IMBUE BOTTLE BODY FINISH
SHEET
MATT
A4 1:3
SCALE
DRAWING NUMBER 4.3 SHEET 1 OF 2 SHEETS
8
B
DRAWING NUMBER 1.2
1
ITEM NO.
2 3 4
D
C
PART NAME
1
BOTTLE BODY
2 3
BOTTLE CAP LOCKING COLLAR
4
LOCKING PIN
5 6 7
MOUNTING TUBE FILTER HOUSING FILTER MESH
MATERIAL SHORE 40A SILICONE PET STAINLESS STEEL STAINLESS STEEL PET PET TITANIUM
QTY.
A
1
4. L
1 1 1 1 1 1
3. LOCKING COLLA
5
DOUBLE START SCREW THREAD M27(ISO 724:1993)
6
7. FILTER MESH
7
1. BOTTLE BO
8 A
NONE
COPY MODIFICATION
20/05/2014
DATE
H.B DR'N
A.G CH'D
23/05/2014 GENERAL DIMENSIONAL TO
AP'D
THIRD ANGLE PROJECTION UNIVERSITY OF BRIGHTON SCHOOL OF COMPUTING ENGINEERING & MATHEMATICS
MACHINED LINEAR TOL. UNMACHINED LINEAR TOL. OTHER TOLERANCES STATE MACHINING SHOWN THUS
REMOVE ALL BURRS & SHA SEE DRAWING NUMBER
E
H
G
F
1
4. LOCKING PIN
2. BOTTLE CAP
2 5. MOUNTING TUBE
3 6. FILTER HOUSING
4
LLAR
5 6 7
BODY
8
L TOLS.
0.25
. OL. ATED HUS
0.15 0.25
HARP EDGES
MATERIAL TYPE
MATERIAL FORM
AS PER ANNOTATION
Injection Moulded
IMBUE ASSEMBLY DRAWING FINISH MATT, PANTONE 360C
SHEET
SCALE
A4 1:3
DRAWING NUMBER 1.2 SHEET 2 OF 2 SHEETS
Evaluation Vs PDS Performance Requirements Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula Function 3/4 eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient Appearance 2/2 montes, nascetur ridiculus mus. Donec Reliability 2/3 quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat Environment 4/4 massa quis ac, enim. Aliquam lorem ante, Production dapibus in, Cost 4/4 viverra quis, feugiat a, tellus. Phasellus viverra nulla ut metus varinec Ergonomics 3/3 odio et ante tincidunt nibh. Donec sodales Quality 2/2 sagitnec, pellentesque eu, pretionec quam felis, ultricies nec, pellentes nec, Weight 2/2 pellentesque. Donec vitae sapien uturis sit amet nibh. Donec sodales sagitnec, pellentesque eu, to pretionec quam1.a, felis, The product fails meet criteria however ultricies pellentesque eu, pretionec this is duenec, to human factors testing, which found quam felis, ultricies pellentesque eu, and the product to be nec, too large for females males with smaller hands. The new metric for PDS point 1.a) will be the product must contain ≤ 700ml of water, this will have the effect of making the bottle smaller and increasing the flavour of the drink as there is less water for the fruit juice to diffuse into. The product also fails to meet PDS point 3.c) 800N is too great a force for the bottle to withstand. Although it in the same market sector as PET plastic bottles, making it possible to remove all of the parts has decreased the structural integrity of the bottle. The bottle will still be able to withstand day to day use but users will have to choose if they value strength or juicing when they purchase their bottle.
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Manufacture Requirements Process 1/1 Materials 3/3 Assembly 4/4 Packaging 3/3 Quality 5/5 Delivery Date 1/1 Manufacture requirements are difficult to assess at this stage in the design process because the product is still in the development stage. If Imbue processes to manufacture then it will strive to meet all BS/ISO/EN quality standards mentioned in the PDS
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Evaluation Vs PDS Desire
Operation Requirements
Disposal Requirements
Installation 1/1
Use 11/11 Maintenance 5/5 Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula Safety 4/4 eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient Human factors has mus. provided some inmontes, nasceturtesting ridiculus Donec sight felis, into how far the will meet quam ultricies nec,product pellentesque eu, these requirements. Further and testing pretium quis, sem. Nulladevelopment consequat massa is required fully evaluate thedapibus maintainance quis ac, enim.toAliquam lorem ante, requirements these in, viverra quis, as feugiat a, tests tellus.require a finished product. Phasellus viverra nulla ut metus varinec odio et ante tincidunt nibh. Donec sodales sagitnec, pellentesque eu, pretionec quam Acceptance Standards felis, ultricies nec, pellentesque nibh. Donec tae sapien uturis sit amet nibh. Donec sodales sagitnec, pellentesque eu, pretionec quam felis, ultricies nec, pellenInspection 4/4 tesque eu, pretionec quam felis, ultricies Testing 2/2 nec, pellentesque eu, Patents 2/3 The product does not infringe on any patents or IP however it has failed to meet point 3c. the textured surface in the bottle could have been patented, however the funds to do so were not available at the time. The judgement to exhibit was made in order to promote the designer rather than to sell the product.
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Standards 1/1 Legislation 2/2 Company Policy 3/3 Hazards
1/1
Disposal requirements are a goal to try and achieve when the product is fully developed. At this stage packaging has not been considered. However the use of recycled material in packaging is a matter of cost and due to the relatively low cost of the product (£3.21 per unit) more money could be spent to have recycled packaging. This is a decision to make with investors when the product goes to market.
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References References Boothroyd, G., Dewhurst, P. and Knight, W. (1994). Product design for manufacture and assembly. 1st ed. New York: M. Dekker. Dobbs, S. and Hayward, D. (2014). The Ultimate Guide to 3D Printing. 1st ed. London: Dennis Publishing Ltd, p.All. Dumas, J. and Redish, J. (1999). A practical guide to usability testing. 1st ed. Exeter, England: Intellect Books. Engineeringtoolbox.com, (2014). Threads - Metric ISO 724. [online] Available at: http://www. engineeringtoolbox.com/metric-threads-d_777.html [Accessed 1 Jun. 2014]. Injection Molding of XIAMETER Liquid Silicone Rubber. (n.d.). 1st ed. [ebook] p.All. Available at: http://www.dowcorning.com/content/publishedlit/95-716.pdf [Accessed 8 May. 2014]. Lefteri, C. (2006). Plastics 2. 1st ed. Hove: RotoVision,. Lidwell, W., Holden, K., Butler, J. and Elam, K. (2010). Universal principles of design. 1st ed. Beverly, Mass.: Rockport Publishers. Ulrich, K. and Eppinger, S. (1995). Product design and development. 1st ed. New York: McGraw-Hill.
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