VOLUME 2, ISSUE 4
APRIL 2009
REGISTRATION IS NOW OPEN!
6TH ANNUAL SOUTHERN METAL FINISHING CONFERENCE & EXPOSITION IN CHARLESTON, SC SEPT. 13-15, 2009
CONTENTS INDUSTRY EVENTS
2
NEWS & NOTES
3
FROM THE FORUMS
6
FINISHING SPOTLIGHT
9
THE LAST WORD
15
Inside This Issue:
T
he International Surface Finishing Academy (ISFA) has announced that registration for the 2009 Southern Metal Finishing Conference is now open. The highly anticipated annual metal finishing exposition will be held Sunday September 13th through Tuesday September 15th in historic Charleston, SC at the Francis Marion Hotel. Celebrating its 6th year, the 2009 Southern
(page 6) “Rising Sulfate Levels”
Metal Finishing conference lineup includes four intensive 2-day training workshops on Hardcoat Anodizing, Powder Coating, Industrial Parts Cleaning and the internationally recognized Kushner Electroplating Course. In addition to well known workshops, the conference will also feature a second 2 day tract of specialized technical
Finishing Spotlight: NASF Washington Forum April 28-30
From the Forums
(page 9)
sessions covering industry hot topics such as the lead free directives of WEEE and RoHS mixed in with various other helpful presenta ti ons like “Sales and Marketing for the Job shop”. Conference attendees will all have the opportunity to discuss specific issues, and learn about new technologies from leading industry vendors in the two day exposition of exhibits, through several organized luncheons, and during the popular opening night Reception. Continued on page 4
(page 15) The Great Face Book Experiment!
“Face Book and the Metal Finishing Industry”
Page 2
FINISHING TALK
INDUSTRY EVENTS 2009 April 7-8, 2009 SFA Powder Coating Course San Jose , CA www.surfacefinishingacademy.com
May 19 - 20, 2009 National Industrial Fastener Show-East Columbus, OH www.fastenershows.com
Jul 15 - 16, 2009 Latin American Coatings Show 2009 Mexico City, Mexico www.coatings-group.com
April 18-20, 2009 2009 MEP National Conference Orlando, FL www.mep.nist.gov
June 7 - 11, 2009 AeroMat 2009 Dayton, OH www.asminternational.org
August 16-20, 2009 American Chemical Society Fall Expo Washington, DC www.acs.org
April 20-22, 2009 Aluminum Assn. 2009 Spring Meeting San Antonio, TX www.aluminum.org
June 15 - 17, 2009 Sur-Fin 2009 Louisville, KY www.nasf.org
September 13-15, 2009 Southern Metal Finishing Conference Charleston, SC www.surfacefinishingacademy.com
April 28-29, 2009 NASF Washington Forum Washington, DC www.nasf.org
Jun 21 - 24, 2009 ASTM Mtg on Paint & Related Coatings Norfolk, VA www.astm.org
September 14-17, 2009 The ASM Heat Treat Society Expo Indianapolis, IN www.asminternational.org
May 4-7, 2009 Porcelain Enamel Inst. Tech Forum Norcross, GA www.porcelainenamel.com
Jun 23 -25, 2009 SFA/MFN Shot Peening and Blasting Houston, TX www.surfacefinishingacademy.com
September 22-23, 2009 Wood Coatings and Composites Expo Charlotte, NC www.coatingstech.org
May 18 - 20, 2009 COATEXPO China 2009 Guangzhou Int'l Convention Center www.coatexpo.cn/en
July 14-15, 2009 SFA Powder Coating Course Jupiter, FL www.surfacefinishingacademy.com
For more calendar events please visit our website: www.finishingtalk.com/events
Page 3
V O L U M E 21 , I S S U E 48
NEWS & NOTES Rutherfordton, NC The International Surface Finishing Academy has launched four new courses that will tour the US during 2009. New course offerings include the MFN Shot Peening Workshop Series, Introduction to Anodizing, an intermediate level Hard Coat Anodizing Course by the Light Metals Institute, and the Internationally recognized Kushner Electroplating School taught by Technic. You can find more information about all of the courses and workshops offered by the Surface Finishing Academy as well as online registration is available on their website at www.surfacefinishingacademy.com Mexico City, Mexico Mexican tariffs that take effect this month for the US. It is estimated that the tariffs will impact $2.4 billion in annual trade through 89 U.S. products, ranging from fruit and wine to washing machines, according to the Mexican government. Some say that Mexican officials appear to have targeted products from states represented by lawmakers who are influential in Congress or have some kind of voice on trade issues. The US had previously agreed to grant Mexican trucks full access to its highways by January 2000 under the North American Free Trade Agreement. Teamsters unions, US consumer groups, and independent insurers have warned that Mexican trucks are unsafe and lobbied Congress to keep them out. Cordoba, Argentina Argentine President Cristina Kirchner submitted a bill this month to renationalize a Lockheed Martin Corp. aircraft maintenance and modification center in Cordoba. It provides depot-level maintenance for the Argentine Air Force, and other military and commercial customers. Argentina privatized Fabrica Militar de Aviones in 1995 in a deal with Lockheed Martin, which used the factory to upgrade IA63 Pampa jet trainer aircraft. The renationalization of the facility is portrayed as a bid to make industrial development the leading edge of the Argentine economy. Leesburg, VA SkillsUSA recently announced that they will offer industry-
driven knowledge and skill assessments in technical areas that correspond to many career cluster areas. These Skill Connect Assessments are part of the SkillsUSA Work Force Ready System. Skill Connect Assessments help students show they’ve got what it takes to begin rewarding careers while helping instructors prove the benefits of career and technical education programs. Local employers can have more confidence in the competency of a skilled work force. This spring, eight of the 46 technical assessments will be available online with simulations and features that deliver a reliable assessment for CTE students. As more assessments are developed, they will be housed in an online system that provides technical assistance, student progress tracking and the opportunity for instructor feedback on the assessments. For more information on CTE please see www.workforcereadysystem.org Atlanta, GA Suniva, the Southeast’s first solar cell manufacturer has announced that it had commenced manufacturing high-efficiency, low-cost solar cells at their new facility. The company expects to create 100 green jobs in 2009, with the potential for more as it scales to full production capacity by 2010. The output of Suniva’s new production facility will grow in stages. The first 32 megawatt (MW) manufacturing line is already producing cells that are being shipped to customers around the world. The company plans additional production lines to bring the facility’s capacity to 175 MW by early 2010, potentially adding more jobs to its work force. Saltillo, Mexico Daimler Trucks North America has opened a new manufacturing plant in Saltillo, located in northern Mexico. The new facility cost Diamler Trucks over $300 million and is expected to create over 1,400 jobs. The plant covers 1.3 million square feet and includes a production facility, a logistics center, administration building, and a training center. The plant will produce Freightliner's new Class-8 truck. The Saltillo plant is the second Daimler Trucks North America manufacturing facility to be located in Mexico. The other is the Santiago Tianguistenco plant, which produces Freight-
liner-branded heavy and medium-duty trucks for export to Latin America, the US, and Canada. Faridabad, India Mahindra Defence Systems (MDS), one of India’s leading providers of special light military vehicles, today inaugurated the Mahindra Special Military Vehicles (MSMV) facility at Prithla in Faridabad, NCR. Spread across six acres, this modern plant has facilities for specific military manufacturing applications. Aside from manufacturing, the plant also has an advanced facility for R&D, product development, design and prototyping of special vehicles to meet specific customer requirements. Wayne, PA The Triumph Group Inc, which designs, engineers, manufactures, repairs and overhauls aircraft components and accessories, stated recently that it will establish a new manufacturing facility in Zacatecas to complement Triumph's existing manufacturing sites. The initial investment is expected to be $20 million over two years. The facility is predicted to employ up to 400 people and it will be accretive to earnings towards the end of fiscal year 2011. Pune, India Mercedes-Benz India formally inaugurated its new manufacturing plant in Chakan, Pune. The new facility was completed within 13 months from the start of construction - among the fastest green-field projects ever created. With an area of 100 acres of land and independent assembly facilities for passenger cars and commercial vehicles, the infrastructure was created to address future expansion needs, underscoring the long-term growth plans of the company in India. Waltham, MA Raytheon Co. won a $27 million contract to provide radar systems for The Boeing Co.’s Ground Based Midcourse Defense program. The six-month contract calls for the Waltham, Mass. defense company to continue development of its weapons system radars aboard vessels developed by Boeing and at various military installations in the United States and the United Kingdom.
~FT
Page 4
FINISHING TALK
CONTINUED FROM PAGE 1...
The Southern Metal Finishing Conference is an event dedicated to metal finishing professionals from all over the US, Europe, other countries abroad who choose to attend for the value of the workshops and technical sessions, to increase their technical skills, and to net-
work with fellow metal finishing professionals, in a historic setting. Hosted annually by the ISFA, the event is rapidly being seen around the globe as a rare and unique opportunity for maximizing educational and networking requirements in a changing international industry.
The three day conference, known for combining entertaining social networking with educational opportunities, has the following events lined up for 2009: Finishing Market Swamp Fox Scramble, PF Online Fishing Tournament, Annual Scavenger Hunt, Rickshaw Races, and even a Live Taping of the hit industry IPTV show “Finishing Talk Live”.
Southern Metal Finishing welcomes and encourages event sponsorships by providing discounted packages to select vendors and OEM’s, each with unique and exclusive access to the heartbeat of the Metal Finishing Industry, through an easy to use online purchase process hosted on the official ISFA website. Space is always limited for this event, and early registration is highly encouraged by experienced attendees. For more information about the Conference please contact the International Surface Finishing Academy office at (828) 2453482, or for online registration visit the ISFA website at www.surfacefinishingacadmey.com/ conference
Page 5
VOLUME 2, ISSUE 4
JAR TEST PROCEDURES
FOR PRECIPITANTS, COAGULANTS AND FLOCCULANTS
P
recipitation is the chemical conversion of soluble substances (including metals) into insoluble particles. Coagulation and flocculation cause a chemical reaction that promotes the formation, agglomeration or clumping of such particles to facilitate their removal from solution. The amount or dosage of a precipitant, coagulant and/or flocculant required to precipitate and remove metals in wastewater solutions is not only dependent on the concentration of such metals in solution, but also on several other factors. To optimize the dosage, the following parameters must be considered:
and complexing agents present in solution. -The amount of residual oxidizers present in solution. -The coagulants and flocculants used. -The sequence in which chemicals are added. JAR TEST PROCEDURE As stated, untreated process wastewaters may contain chemicals other that dissolved metals that will affect the treatment methodology. Therefore, the procedure which follows provides a starting point and adjustments may be required to achieve the desired results.
-The different types (and concentrations) of metals present in solution. -The amount and types of chelants
3. 300 ml - 1000 ml Beakers, clear plastic or glass. 4. Magnetic Stirrer or equivalent. 5. Syringes for adding chemical reagents. 6. Laboratory Type Filter. 7. Metals Test Kit or AA Spectrophotometer, etc. CHEMICAL REAGENTS: 1. Sodium-Hydroxide (Caustic-Soda) solution. 2. Sulfuric-Acid solution. 3. Precipitant(s). 4. Coagulant solution(s) – see product bulletin for suggested dilution ratio.
-The solution pH. -The chemical used to adjust the pH (i.e. NaOH, lime, Mg(OH)2, Na2CO3).
BY: GORDON DJANI
RECOMMENDED EQUIPMENT: 1. pH meter with electrode to monitor pH. 2. ORP meter with electrode to monitor the reduction reaction.
5. Flocculant solution(s) – see product bulletin for suggested dilution ratio. Continued on page 10
Continued on page 8...
Page 6
FINISHING TALK
FROM THE FORUM: RISING SULFATE LEVELS
T
was being dragged into the chrome. We fixed this his month we’re taking a look at an issue with ris-
by creating a chrome pre-dip bath before the
ing sulfate levels that Finishing Talk Member “Jason”
chrome bath.
is trying to understand and get a handle on. Veteran
~4opg of chromic acid and a maintained level of
members Ira Donovan, and Dustin Gebhardt,
sulfate that was 1/2 of the concentration in the
have had an interesting discussion with Jason about hard chrome plating baths in general, but there are
This was a stagnant bath with
actual chrome bath.
The level of the sulfate
still an few unanswered questions on this one. Please
would rise over time, and once it reached the
feel free to add your thoughts to this posting in our
same concentration of the chrome bath, the pre-
online
at
dip was dumped and remade. On a side note, we
www.finishingtalk.com/community, and choos-
also electrified this bath, which greatly helped with
forum.
You
can
find
it
ing the Powder Coating Forum. For more “From the Forum” discussions, check out our internet IPTV television show, Finishing Talk Live, where hosts Paul Fisher and Paul Skelton
maintaining an active surface before chrome plating.
This greatly reduced the amount of false
burn we produced.
bring our bulletin boards to life. Watch us today on the only IPTV Channel dedicated to the Metal Finishing Industry.
www.finishingtalklive.com
Ira Donovan The most common sources are incoming water (city or DI) and drag-in. Depending on your location, the city water provided at the tap may have
JASON Hello. My sulfate levels in two of my three baths are getting high. We try to maintain an approx 2.5 gram per liter to a 250 gram per liter between the chrome and sulfuric. Our sulfuric levels keep going up slowly month by month. I guess what I am looking for is, what are some contributing factors of rising levels of sulfate?
levels of sulfates that will build over time in your tank.
DI water should be clean, however there
are those cases where people regenerate their resins with sulfuric acid. Due to insufficient backwashing, there can be an initial slug of dilute sulfuric in the make-up water. Finally, drag-in is commonly due to poor rinsing after a sulfuric acid pickle.
Another potential
source could be entrapped pickle solution in blind DustinGebhardt You must be dragging in the sulfate from somewhere.
Take a sample of the bath before the
chrome and test it for sulfate. I've seen this problem before when the rinses between nickel plating and chrome plating were insufficient and sulfate
holes or recesses that is not being effectively rinsed. Along the same lines, if your racks or fixtures have peeling plastisol or other coatings, pickle solution can become entrapped in those locations as well. I hope this helps.
Page 7
VOLUME 2, ISSUE 4
first place, I would check your rinsing practices.
JASON Thanks for the reply Dustin. We only do hard chrome, no nickel. I was told that the only way to increase your sulfate levels was to add sulfuric
Poor rinsing, especially with blind parts or parts that can trap solution, is a major contributor to contamination.
acid. We have not added any for months. I will be changing my bath in the New Year due the high levels of other contaminants. Can high evils of iron, copper and trivalent be the culprit? I am currently adding barium carbonate to try and neutralize the sulfate. I am open to any suggestions. We also do a lot of inside dia. plating in the two problem tanks. The most logical explanation for the rise is, tap water. We use our local water to rinse parts and replenish lost solution levels. We have
JASON We do not use porous pot. What is the typical bath life if using porous pot? We are mostly a recon shop, so small defects are usually not a concern due to over plating and finish grinding to a certain size. A typical bath life for use is 6 to 7 years. It seems that if we keep our ratio in check, we do o.k. This is now the problem.
our own lab and I will get them to test the sulfate levels in our tap water.
www.finishingtalklive.com
Ira Donovan Jason, The incoming city water is a definite concern for you. The incoming levels will concentrate as you continue to add back water for evaporation. As for your contaminants, I do not think those will contribute to any sulfate issues. Are you using a porous pot or dummy cell to control your contaminants and trivalent chrome? This is common practice for most hard chrome operations to extend bath life.
DustinGebhardt I second the recommendation for the porous pot. When run correctly, they greatly extend the life of a chrome bath by filtering out contaminants and converting tri-chrome back to hex-chrome.
As far
as reducing the buildup of the contaminants in the
Page 8
FINISHING TALK
Page 9
VOLUME 2, ISSUE 4 FINISHING SPOTLIGHT: NASF’s WASHINGTON FORUM 2009
T
he NASF Washington Forum is scheduled this year for April 28-30, 2009 at the L’Enfant Plaza Hotel in Washington, D.C. The 2009 Forum will include presentations on critical regulatory, technical, policy and legislative issues impacting the surface finishing industry. Nationally acclaimed Washington pundit, Fred Barnes, will make a keynote address on the 2008 elections. By participating in the Washington Forum, attendees stand to gain new insights on Washington and global policy developments that impact surface finishing. This Forum brings together industry’s top analysts and national decision makers for two days to discuss fundamental issues facing the industry. Key briefings will be presented on both emerging threats, as well as opportunities for finishers. Sessions will cover a range of topics, including: • The U.S. Economy and Small Manufacturing Competitiveness • The Changing Regulatory Picture on Chemicals for Finishers and Suppliers • Energy Policy, Climate Change Legislation and Your Operation • The Labor Agenda and What It Means in 2009 and the Future • A "Post-Chromium World" in the New Administration? After the briefings, attendees will have the opportunity to meet with lawmak-
APRIL 28-30, 2009
ers on Capitol Hill to discuss surface finishing needs. The value of a good relationship with your Congressional representatives can't be overstated, and through this Forum attendees have the opportunity to give their elected representatives some real up to date insight into the finishing industry and the challenges that we're currently facing. Register for the Washington Forum today by visiting the NASF website at www.nasf.org and reserve a room online at the L'Enfant Plaza. You may
also contact The Policy Group’s Christian Richter (202) 257-0250 or Jeff Hannapel at (202) 257-3756 for assistance in registering. See this article in our On-line Forums to download the Washington Forum Agenda
2009 Washington Forum www.nasf.org
Page 10
FINISHING TALK
C O N T I N U E D F R O M P A G E 5 ‌ JAR TEST PROCEDURES BY: GORDON DJANI PROCEDURE:
flocculation reactions.
1. Pour a sample of untreated wastewater into a beaker (ex 1000 ml). While mixing, adjust the pH using caustic soda or sulfuric acid to the optimum pH for hydroxide precipitation of mixed metals, i.e. pH 8.5.
To project the dosage results from a jar test to full scale, the following information may be helpful:
2. While mixing the sample, use a syringe to add the precipitant until the ORP value drops rapidly by 150mV (typically to -250 mV). If an ORP meter with electrode is not available, use several beakers and add different amounts of precipitant to each beaker. Please note that, although the precipitating reactions appear to be instantaneous, a retention time of up to 15 minutes may be required to obtain a complete reaction. 3. Add 100 to 200 ppm (approx. 0.10.2ml to 1000ml) of coagulant solution. Mix at high speed for 1 to 3 minutes. Turn off mixer and observe the coagulation (agglomeration) of the precipitated particles. Monitor the pH, as certain coagulants are acidic in nature and will alter the pH. If the particles appear to be coagulating but need assistance to accelerate their settling, a flocculant may be added to the solution followed by a slow mixing to allow for floc building. If the settling action is too slow or incomplete, redo the test using more of the coagulant solution 4. After several minutes, a sample of clear supernate may be taken for metals test, or the entire contents of the beaker (s) may be filtered to remove solids, then the filtrate tested/analyzed. Note: When the supernate has a yellow or orange tint (similar to the color of the precipitant), that is an indication of overdosing the precipitant. If necessary, dilute the precipitant before adding it to the wastewater. Make note of the dilution ratio for determining the optimum full-scale dosage. Overdosing the precipitant can also cause a significant increase of colloidal particles and may interfere with the normal coagulation/
1 drop = 0.05 ml 1 drop per liter = 50 mg/l (ppm)
PRECIPITANT CONTROL SYSTEM Precipitant control systems utilize an electrode for accurate measurement (in millivolts) of the reduction reaction of precipitants in wastewater. The electrode signal is monitored by the controller that controls the metering pump for dosing the required amount of precipitant. Systems are also available for pH adjustment under electrode control.
pH The solubility of metallic particles is pH dependent. That is, dissolved heavy metal ions can be precipitated chemically by adjusting the pH of a wastewater stream. The pH is important because all metals have a pH at which their solubility is minimal. Although this pH differs for all metals, it generally lies between 7.5 and 11. Since most wastewaters contain a variety of metals, it is difficult choosing the optimum pH at which their solubility is minimal. See attached chart for optimum removal ranges. Precipitants will simultaneously precipitate a variety of metals at any given pH within the above range. These precipitants, with low solubility, can achieve very high removal efficiencies. When used as a "polishing" precipitant, the dosage of a precipitant can be lowered depending on the quantity of metals that are precipitated as hydroxides by pH adjustment. While a pH of 8.5 is normally recommended for the polishing effect -- the pH value will vary depending on the presence of chelating and/or complexing agents in the wastewater. A jar test procedure as described above can help to estab-
lish the optimum pH within the 7.5 to 11 range. For example, if nickel is the main metal of concern, adjust the final pH to 10 to fully optimize the effects of hydroxide precipitation. For adjusting pH, sodium hydroxide is recommended. However, other common chemicals can be used -- such as soda ash and lime. For some applications (nickel complexes) magnesium hydroxide is an effective reagent.
RESIDUAL OXIDIZERS When a precipitant is added to a wastewater stream containing residual oxidizers along with dissolved metals, dual reactions occur. These reactions are: 1) the reduction of the oxidizers and 2) the precipitation of the metals. This, of course, increases the amount of precipitant required for total metals precipitation. To optimize the usage of a precipitant, adding a reducer (i.e. sodium metabisulfite) before the precipitant addition will remove the oxidizers from the wastewater solution.
FLOCCULANT/COAGULANTS Characteristically the insoluble particles formed by adding a precipitating reagent to a wastewater solution are very small and suspended in the solution (colloidal). The suspended stability of such particles is due to both their small size and to the electrical charge (usually negative) on their surface causing them to repel their neighboring particles. To promote the removal of these suspended particles use chemical coagulation and/or flocculation. Adding coagulants to the wastewater creates a chemical reaction in which the repulsive electrical charges surrounding colloidal particles are neutralized, allowing the particles to stick together creating clumps or flocs (often called pinfloc). . When required, flocculants with an anionic charge are commonly used to faContinued on next page
Page 11
VOLUME 2, ISSUE 4 cilitate the agglomeration of the floc and their settling. The flocculants act like a net, bringing together a number of the now neutralized particles, allowing for separation. The aggregation of these particles into larger floc permits their separation from solution by sedimentation, flotation, filtration or straining. Some precipitants contain cationic polymers that neutralize the precipitated particles. The cations (positive charges) from the polymer reduce or reverse the negative charges of the
precipitate which, in turn, permits the coagulation and flocculation of the particles. COMPLEXING AND CHELATING AGENTS Some process wastewaters include complexing and chelating agents, which bond to the metal ions making precipitation difficult, if not impossible, for many precipitating reagents. There are a variety of different precipitants capable of breaking many of these bonding agents and thereby precipitating the metal ions without the addition
of other chemicals. In some instances a combination of pH adjustments and varying reaction times may be required along with a precipitant and flocculants.
ODOR CONTROL By oxidation, some precipitants have a characteristic sulfide odor. This odor may be eliminated or minimized by following simple control procedures: a. Assure that the waste stream or sludge contains no oxidizers. b. Dose the precipitant below the wastewater surface to prevent surface air oxidation. c. Use below surface mechanical agitation for mixing. Do not use air agitation. d. Do not overdose. The Reagent Control System mentioned above will prevent overdosing. e. Maintain a wastewater pH of 7.0 or above. f. Utilize mechanical exhaust ventilation. g. Use closed top reaction/mixing tanks when possible. h. After wastewater clarification, any sulfide odor or color is a positive sign of overdose. If
•
impractical to control dosing, excess may be easily removed with a minimal injection of peroxide or hypochlorite in the effluent.
Written By: Gordon Djani Water Specialists Technologies
www.waterspecialists.biz You can find graphs and charts with this article, and ask any questions you may have in our online forum: www.finishing talk.com/community
Page 12
FINISHING TALK
THE ORIGINS OF MASS FINISHING BY: PAUL RAWLINSON, RÖSLER US.
L
ast August I reached a personal career milestone of 30 years in the Mass Finishing industry. Whilst this may seem like a long time to some people, the Mass Finishing process goes back very many more years, so I thought it may be appropriate to take this opportunity to look back to the origins of the technique and how it all began.
The background to the process It might be said that the origins of the process can best be seen as nature’s way of smoothing and polishing a variety of materials. For example, you rarely see a pebble on the seashores that has not been smoothed and rounded by the tumbling action of the waves and the abrasive action of the sand granules. This action is perfectly reproduced in the early barreling machines and later in vibratory and centrifugal systems. The origins of the process in more recent times of man’s history may well have come from the fact that in roman times soldiers would carry their armour and harness fittings in bags of sand slung across their horses back. The abrasive action thus generated by the movement of the horse kept the parts clean and bright for ceremonial occasions.
The history of the process The earliest records of barrel finishing are to be found in patents taken out in the mid 19th century, about the year 1850. Early machines were quite simple. Wine casks or beer barrels were mounted on simple bearing systems and usually turned by hand. Into the barrels the components would be placed, usually without media. Mostly the process was used to remove molding sand and scale from sand castings prior to machining or other finishing processes. Later on they attempted to improve the process by adding crude forms of media. This usually comprised natural or easily obtained materials which included metal swarf, small cast star shapes, steel shot, coke, granite or limestone chippings and for polishing they used a mixture of old machine and emery with pieces of worn leather machine drive belts. Surprisingly quite good results were sometimes achieved by these rather crude methods but the process was hit and miss and was restricted to components of low value which could withstand the harsh treatment to which they were submitted. However, it was from such beginnings the modern processes and machines were evolved. Development in the field of mass finishing grew rapidly from these
simple beginnings, this was brought about by the equally rapid growth of technology in product manufacture in the engineering industry. The increase in the production of precision components made it necessary that more efficient and less labor intensive ways should be found to deal with the finishing of the parts. In 1935 a committee was set up in the USA to investigate means by which these problems might be solved. They quickly saw that the needs of the industry might well be served by a development of those crude barreling or as they were often known ‘rumbling’ processes. All the subsequent developments in the processes and the equipment have grown from these early beginnings. These early developments have played (and still do) a significant roll in the growth and status of the contemporary Mass Finishing Industry. Paul Rawlinson Tel: +44.151.482 0444 Fax: +44.151.482 4400 E-mail: prawlinson@rosler.us This article was reprinted from the March edition of MFN with permission of the author Paul Rawlinson, Contributing Editor for MFN and General Manager of Rösler US.
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VOLUME 2, ISSUE 4
RACKING, A SENSITIVE PART OF THE ANODIZING PROCESS FROM ANODIZINGWORLD.COM , A BLOG BY ANNE DEACON JUHL
When the parts arrive in the anodizing shop, even before starting to process the aluminum parts, they need to be unpacked and racked. It is important to have a clear agreement with the anodizer on how the parts are to be be racked. The areas where the rack and the part will touch will not be anodized. Racking, also called jigging, is one of the most important steps in the anodizing process. The basic functions of the racking is to hold the part tight during transfer between the different process tanks and to provide sufficient contact to the part, so that enough current can run, to form a uniform layer on the aluminum part. In addition to this it is important that the racks are designed so that no solution from the process tanks can be entrapped. Aluminum and titanium are the most common materials for racking before anodizing. There are advantages and disadvantages of both materials. Advantages in using aluminum rack: •
Low price
•
Easy to machine
•
High electrical conductivity
Disadvantages in using aluminum rack: •
Attacked chemical and electrochemical
•
Soft material
•
Advantage in using titanium rack:
•
High strength and durability
•
Chemical inert, except from fluorides
Disadvantage in using titanium rack: •
Expensive when purchased
•
Specialized needs for repairing
•
Less electrical than aluminum
conductivity
The electrical conductivity is a very important property when anodizing. The most efficient utilization of the energy is when all the current is sent to the parts. Titanium has an electrical conductivity of around 10% of aluminum. The conductivity of aluminum is highly dependent on the alloy used. The rule of thumb for design of aluminum racks is 1,000 amperes per square inch. The comparable value for solid titanium is 350 amperes per square inch. Titanium racks can be designed and used to give the most optimal anodizing result of the aluminum part. The reason for this is that titanium only forms a very thin oxide layer which is readily removed in the process of racking new parts. The only "but", is that titanium racks should not be used when the parts are electrolytical colored. Aluminum will anodize along with the work and if not carefully selected it will actually steal all the current from the parts to be anodized. So after anodizing, aluminum racks have to be stripped to remove the formed oxide layer. This issue reduces the life of the aluminum racks tremendously.
Two aluminum alloys which are considered as good racking materials are 6061 and 2024. The reason for this is that they anodize very slowly compared to a lot of other aluminum alloys. Instead of using racks, a lot of anodizers use plastic clamps for fast racking of extrusions. Using plastic clamps will give less aluminum in the waste treatment due to the fact that the plastic clamps should not be stripped after the anodizing process as the aluminum bolts and nuts. The plastic clamps can also be used together with bolts and nuts, as photo below show.
Courtesy of Burlingham International
If you have questions, or would like more information about this topic please contact:
blog@aluconsult.com
Page 14
FINISHING TALK
THE LAST WORD
THE GREAT FACE BOOK EXPERIMENT
Y
BY: PAUL FISHER
of online social networking that
searches for people with similar
ou may have thought the
Face Book is—they both foster
interests.
same things I did when first
and encourage sharing in many
this I typed “Metal Finishing” into
confronted with the whole Face
ways including community, col-
the search field not expecting
Book
You’re
laboration and business net-
much, but low and behold it re-
thinking you don’t have the
working. So I announced to the
trieved hundreds of hits!
time, or that it’s just plain stu-
office
pid, or maybe that it’s just for
around on Face Book at the of-
kids. We’ll I’ve got news for
fice, as long as they always tied
you…. you are right! Face book
it into something to do with Fin-
can absolutely be an enormous
ishing Talk and the Metal Finish-
time-sucking black hole, much
ing Industry.
Phenomenon.
like the internet in general. But
that
they
could
tool
The first time I tried
When this happened I quickly knew I was ready to finish this experiment, and finalize this article (and possibly move on with my life). So I changed my status (you’ll have to figure this one out
We’ll, as some of you may have
on your own, but it deals with
guessed (and others may have
the “broadcasting your life” part
heard), this little experiment
of Face Book) to “Writing an arti-
didn’t go down without unin-
cle on Face Book and Metal Fin-
tended consequences. Within a
ishing,” and started sending out
few weeks of the new “open
friend requests to everyone on
Let me explain. When I first de-
Face Book” policy going into ef-
the search results.
cided to go forward and suc-
fect, I quickly realized that oth-
many friend requests that day
cumb to the peer pressure to
ers around the office weren’t as
that I received a note from FB
sign up, I felt that I had to
dedicated to my little experi-
asking if I was breaking their
“justify” it in some way. I settled
ment as I was.
“Terms of Service” agreement.
on the justification being in this
spending more time surfing and
article. I decided to use this new
chatting with old high school
form of social networking to see
chums on FB, than they were on
how many metal finishing con-
our own company Web sites. It
nections I could make using
didn’t take long before I asked
Face Book as the medium.
my I.T. guy to block the FB ad-
I’ve recently proved that if its power is directed and focused toward a specific purpose, you can direct the time and energy into a rewarding experience.
To take it a step further (like I tend to do) I announced to my
They were
dress from all computers in the office except for mine.
I sent so
As this article is written, I now have 400 new friends who have an active interest in Metal Finishing and Industrial Manufacturing from all over the world. number
is
growing
That
everyday
now, and I do mean from all over the world. I actually had a
office shortly after this experi-
OK – so now for the good re-
conversation with an engineering
ment began, that I wanted
sults.
It took me a while to
student in Sri Lanka about metal
them to participate, too.
After
learn how to use the built-in
finishing a couple of Saturdays
all, Finishing Talk’s forum is
tools, but eventually I figured
ago.
based on the very same concept
out how to conduct targeted
signed up for a membership on
He turned around and
Page 15
VOLUME 2, ISSUE 4 Finishing Talk right after our
up a new “Finishing Talk Live”
boards after this article is pub-
discussion.
fan club through FB too. With a
lished so our Finishing Talk
knew
couple of clicks I was able cre-
members have a chance to
Plating,
ate an event and let all of my
weigh in on this one.
Meminger Metal Finishing, Com-
new friends and fans know
plete Metal Finishing, and Dana-
about the next filming date for
her.
And then I found others
our next show - Episode 8. This
that were completely new to me
episode should have a pretty
like Dragon Powder Coating,
interesting audience. So far we
Moore Metal Finishing, Acme
have fans from places like Af-
Metal Processing, and the Hol-
ghanistan, Paris, Germany, Aus-
zapfel Group in Germany.
I
tralia and Mexico who have indi-
even found a couple of shops
cated on our Face Book event
right in my backyard that I’d
page that they will be attending
never heard of before like Preci-
this live taping!
sion Metal Finishing, LLC in
what you’re thinking, but I’m
Abbeville, SC and Hot Box Pow-
thinking those are some dedi-
der Coating in Charlotte, NC.
cated fans!
You can also meet tons of peo-
The
ple with the common interest of
starting to work too. Just yester-
metal finishing and industrial
day there was a great question
manufacturing by joining the
about standardizing metal fin-
various groups formed on Face
ishing processes posted on my
Book. Ted Mooney (The God
page
Father of Metal Finishing) from
“Question:
Finishing.com has one called
standardizing a plating process
Metal Finishing that I belong to;
and training to the standard
there is one on Electroless Plat-
without
ing, Powder Coating, and there
knowledge?
is even one for… you guessed it!
asked the experts in our com-
Finishing Talk! When you get a
pany on how to Electroless Ni
chance, sign up for the group
plate. We would most likely re-
and I’ll introduce you to the
ceive very different ideas on the
hundreds of other metal finish-
sequence
ing and engineering profession-
chemistry used...each method
als who I’ve made friends with
may end up with a good plated
over the past few months.
part.” I’ll be moving this ques-
shops
that
about,
like
I found people at I
already
Pioneer
Of course I went ahead and set
I don’t know
collaboration
that
is
went
already
like
this.
Any insight into
losing
the
Example,
of
creative if
operation
we
and
tion over the Finishing Talk
Lastly, something else extremely interesting that I discovered was a number of younger generation metal finishing experts in training that we’ve all been looking so hard for. To date I’ve made friends with nearly a dozen kids with ages ranging from 18-21 who are currently working in the trenches and on the lines in various finishing shops around the world….. who knew!? I hope this experiment helped in some way. Lord knows I’ve invested more time into this article than anything I’ve ever written before—including when I was in college.
If you’re not
careful, Face Book can become just another time sucker like YouTube, but if you do some of the things that I’ve shared here, you can get some tremendous benefits from this new social media.
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April 2009 Paul Fisher, Editor Phone: (828)-245-2601 paul@finishingtalk.com
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