CVG FinishTEK Builds on Hydrographics Excellence 1 – For nearly 20 years, CVG FinishTEK has been perfecting the art of hydrographic finishing in Dalton, GA, providing sleek custom graphics to the powersports and automotive industries. 2 – Employees are actively encouraged to contribute their suggestions for upholding quality and lowering costs. 3 – FinishTEK utilizes hydrographic finishing to provide custom graphics for the powersports and automotive industries. A YouTube video of the hydrographics process is available at www.youtube.com/watch?v=qVROV-yH8QY. by Amy Bauer
For nearly 20 years, Daltek, now CVG FinishTEK, of Dalton, GA, has been perfecting the art of hydrographic finishing, providing sleek custom graphics to the powersports and automotive industries.
From popular wood grain, carbon fiber and brushed metal designs for automotive and trucking applications to well-known camouflage patterns for all-terrain and side-by-side vehicles to flashy brights for snowmobiles, the options in hydrographic films only are limited by a customers imagination. Custom patterns and graphics also can be designed with one of several film companies that supply FinishTEK.
Customers who want a conventional paint application also can take advantage of FinishTEKs automated dual 6-axis Fanuc robots, which can finish large and small parts.
The company, formerly Daltek, was acquired in December 2012 by Commercial Vehicle Group, Inc. (Nasdaq: CVGI) and today enhances the capabilities of this worldwide supplier of cab-related products and systems for commercial vehicles, including the heavy-duty (Class 8) truck market; the construction, military, bus and agriculture markets; and the specialty transportation market.
Hydrographics, also sometimes called immersion printing or water transfer imaging, offers 360-degree coverage of a printed design onto dimensional parts. FinishTEKs slogan is, “If it can be painted, it can be dipped.”
“It is not a decal,” explained Phil Raisin, co-founder and director of operations. “The printed pattern is transferred to the part, much like paint in that the carrier film is washed from the part and only the ink remains on the surface. The physical properties are enhanced by a top layer of an automotive clear coat.” Hydrographics meets the most demanding standards for hardness, UV- and chemical-resistance and adhesion to substrate, FinishTEK notes in its product literature.
The process at FinishTEK involves the following steps:
- A base coat of paint is applied to provide background color and a surface to which the film will adhere. The paint is cured by baking.
- Printed PVA (poly vinyl alcohol) is floated on warm water in a large tank. After the prescribed soak time, the film is activated with a mixture of solvents that re-wet the ink and turn the printed PVA into a gelatinous layer with wet ink on top.
- The part is inverted over the tank by a robot and pushed through the PVA layer into the water. The wet ink then transfers onto the part.
- The PVA is washed from the part in a four-stage washer. A final halo of water processed by reverse osmosis, which filters the majority of impurities from the water, sets the stage for the clear coat.
- The part goes to the oven to dry and then is inspected thoroughly.
- A final automotive clear coat is applied, and the clear coat then is cured by baking.
- Finally, the part is again inspected and then packaged for return to the original equipment manufacturer (OEM) for assembly.
“Pictures dont do FinishTEK any justice,” said John Haughian, vice president of operations. “You have to see videos. You have to see how the process goes. Its a marvelous transformation.”
FinishTEK processes a part about every minute, Raisin said. The entire process takes about an hour and a half. Smaller parts are racked, so more are completed with each dip. The company has two robotic hydrographics production lines, and each is bound only by the dimensions of the dip tanks. “We can process parts up to about seven feet long and four feet wide,” Raisin explained. “There are some tricks where we can go a little bit bigger by dipping the part twice.”
Challenges in dipping include controlling stretch, activator levels, film variance and basic process parameters, and FinishTEK controls these things by automating as much as possible, including a Fanuc Robotics Dip, a Servo Driven Activator System and other key controls.
The company originally applied hydrographics to small consumer electronics such as cell phone cases for Motorola and RIM (Blackberry), but as it progressed into larger parts and more complex geometries, robotics became key to maintaining the consistency and tight tolerances that are more difficult to achieve with manual, or hand, dips. “Since weve added robotics, weve gotten very consistent dip results,” Raisin said. “I think weve pushed the industry harder.”
Employees are actively encouraged to contribute their suggestions for upholding quality and lowering costs. Raisin said the company expects each employee to submit suggestions annually and sometimes offers incentives such as T-shirts or other goodies for those who contribute.
One salient suggestion by an employee involved changing dip angles to reduce the amount of tape masking required on a part, thereby reducing the labor time and cost involved in its production. “When youre running thousands of parts, its a pretty impactful change,” Raisin noted.
The vast majority of FinishTEKs hydrographic decorating is on injection-molded and vacuum-formed plastics, but the process also can be used on metal substrates, vinyl and even leather.
FinishTEKs process also is used with aluminum and stainless steel; for example, in side-by-side vehicle (SSV) back beds and some truck cab parts.
FinishTEKs top customers are Honda, John Deere, Yamaha, Bemis and Bombardier Recreational Products. Today, the bulk of FinishTEKs business is in the powersports industry, but the company is seeing growth in the automotive and heavy-duty trucking segments. The connection into the commercial vehicle segments has been facilitated through CVGs long-standing customer relationships.
During the busy powersports season that spans roughly July through the end of the year, FinishTEK runs the plant at much higher utilization and employment rates and then flexes down during the slower spring season. Turnover is low, and many of the employees have been doing this type of seasonal work for 10 to 15 years, Haughian said. The company also encourages cross-training throughout the operation to help facilitate the flexibility of its workforce. FinishTEK operates from a 50,000-square-foot production facility in Dalton and has a 45,000-square-foot warehouse several blocks away.
FinishTEK originally was founded in 1993, painting small injection-molded parts. It began offering hydrographics in 1995 and was one of the first companies in the United States to pioneer that process for decorating parts. FinishTEK automated the hydrographic process in 1997 and in 2004 implemented a robotic dip system.
FinishTEK joined a stable of top brands representing 25 manufacturing locations worldwide under CVGs umbrella, including National Seating, KAB Seating™, Bostrom Seating® and Moto Mirror®. In addition, CVG produces interior systems such as headliners, flooring, interior panels, door liners and various injection molded parts, as well as electrical components, wiper systems and harnesses for all of the various on- and off-road commercial vehicle markets.
“If you look at one of the big sleeper truck cabs you see on the highways today, we can supply almost everything that the driver touches inside the vehicle except the glass and electronics,” Haughian said.
“FinishTEK is a natural extension of the services and products CVG already supplies to the commercial vehicle market,” he said. “It expands our portfolio of products we can provide to our customers today all under the CVG name. We werent as active in the municipal vehicle platforms, which FinishTEK has brought to the table,” he explained. “Now we also have a stronger position in the ATV (all-terrain vehicle) market, the SSVs (side-by-side vehicles) and personal watercraft, such as Sea-Doos.”
CVG provides injection molding at its Cabarrus facility in Concord, N.C., supplying molded parts to FinishTEK to be decorated and sent back to the OEMs for assembly. CVG also injection molds and decorates door components with wood grain hydrographics that go into some of the high-end truck brands.
While hydrographics costs more than paint alone, the opportunity for customization and differentiation creates value for the customer, coupled with the ability to generate an upscale appearance without substantial investment, Haughian said. “You can take an existing platform and give it a whole new look that paint just cant do, and it will set your product apart from everybody else,” he said. “Not to mention, you can match exotic, expensive materials like wood grains and carbon fibers, and you can do it at a much lower cost than using the actual materials.”
Many customers also find that hydrographics are a great way to renew an existing product or program. “A lot of customers enter the market with just a painted version, which we robotically paint for them. Then six months into it they may want to refresh the program, and theyll introduce a carbon fiber or a camouflage or a brushed metal to bring more energy back into the program,” Haughian said.
The potential to expand FinishTEKs work in the trucking industry is vast. Haughian said many people who wouldnt normally come to CVG as customers approached the company at the Mid-America Trucking Show to assess its decorating alternatives. He described excitement about the possibility of applying brushed metal hydrographic prints to items that normally would be sent to be chromed, a more expensive process. “A lot of the interior components really do lend themselves well to the hydrographics application that FinishTEK brings to the table,” Haughian said.
Similarly, Haughian noted that the average lifespan of a large truck design is between five and seven years before the major manufacturers refresh their programs. The next major refresh is expected around 2016, and Haughian said a number of large truck manufacturers are considering FinishTEKs process to cut down on costs. “If youre going to refurbish a truck, youre talking about significant investment in new tooling to get new components made for that truck,” he described. “But CVG FinishTEK can take existing components, modify them by putting them through the hydrographics process and make them look very different.” Higher-end looks such as wood grain and carbon fiber also can command a higher price point for such deluxe finishes.
FinishTEK continues to stretch the boundaries with new hydrographics applications. It has developed a process for applying hydrographics to leather, which it unveiled at this years Mid-America Trucking Show to rave reviews. CVG showed off FinishTEKs decoration of a complete “Duck Commander”-themed truck seat in a RealTree Max-5 camouflage finish popularized by the “Duck Dynasty” reality show stars. While the PVA film is the same for all applications, Raisin said different base coats and clear coats are used for the different substrates, such as leather.
Investing in excellence
Since acquiring the company, Commercial Vehicle Group has been investing in FinishTEK, increasing its hydrographic capabilities and working to expand operations. FinishTEK is wrapping up an upgrade of its major hydrographics lines. Once the upgrades are complete, FinishTEKs automated lines will all operate in a Class 10,000 clean room environment, which is required for high-gloss finishing. “Weve run high-gloss ATV programs for just about all of the OEMs,” Raisin said. “We do a lot of it, and thats why were improving our performance and capacity in that capability.”
Other quality improvements have been implemented to hydrographics line washers, which Raisin said ensure a cleaner part right off the line and allow for better clear coating. FinishTEK also is targeting to achieve TS16949 and ISO 14001 quality certifications by the end of this year.
Future plans may include adding injection molding capabilities to FinishTEKs production facility. “A lot of the product that FinishTEK processes today is consigned materials, so it comes from injection molders other than CVG,” Haughian said. “We are reviewing investments to add injection molding directly into the FinishTEK facility so we can do the molding and decorating under one roof.”
Haughian said hed also like to see Class A painting capabilities within the next couple of years at FinishTEK, and CVG is researching that prospect. “If we see that as a viable business proposition, CVG will invest,” he said. “Our role is to expand on the synergies between CVG and FinishTEK and continue to watch FinishTEK flourish and grow over the next four to five years,” Haughian said. “Weve got high expectations for FinishTEKs future and a fantastic workforce down there to help us achieve those expectations.”
“Our goal is to make sure we continue to be a front-runner in this market for many years, and we intend to accomplish that through prudent investments in new technology and the development of our human capital,” Haughian explained.
Raisin concurred: “Success is 50 percent your people and 50 percent your equipment, and we are investing in both.”
————————- Advantages of Infrared Welding in Thermoplastics Manufacturing sidebar –
Depending on the product and application, the IR welding process is beneficial in that it allows for the following:
- No particles, e.g. for air- or oil-ducting components (more and more regulated by OEM norms and rules)
- The increased use of reinforced high-performance plastics, e.g. glass fiber
- Use of reinforced plastics for structural components and lightweight construction
- Higher yield strength in security-relevant areas
- Design freedom, with a view to complex 3D geometries
- Improved productivity, economic viability and energy efficiency
- Non-contact method
- Higher strengths
- Particle-free process
- 100-percent gas-tightness
by Dave Clothier, FRIMO, Inc.
For several years, the process of infrared (IR) welding has been gaining importance in the thermoplastics industry as a competitive alternative to classic joining techniques used in high-quality thermoplastic manufacturing processes, such as vibration and hot plate welding.
Method and benefits
IR welding is a non-contact joining method that, depending on the product and application, offers many advantages in the way of overall investment, process handling and quality results compared to traditional processes. It is equally well-suited for manufacturing both small and large components. Typical applications include automotive instrument panels, door trims and center consoles that have complex welding contours.
With the IR welding process, energy from the IR process is absorbed by the material and transformed into heat, resulting in the melting of the surface layer and allowing for plastic components to be joined by pressing them together. The heat is transferred without contact, and the heat input is fast, specific and energy-efficient.
Being contact-free, IR welding satisfies the ever-increasing demand for particle-free operation, especially when manufacturing components such as air and oil ducts, fluid containers, tank systems and filters or filter housings, as many original equipment manufacturers of such components are imposing progressively strict standards and regulations.
The IR welding process also allows for impressive design flexibility – even for complex 3D geometries – and is exceptionally well-suited for welding high-performance reinforced plastics, including glass fiber-reinforced plastics and polyamides, which are becoming increasingly commonplace in structural components such as those used in lightweight vehicle applications. In addition, the process offers extremely high degrees of strength and 100-percent gas tightness, which is of particular interest in the production of safety-related components.
Equipment and tooling
Along with the growing popularity of IR welding, there is an increased interest in high-speed process tools and equipment. The demand for IR welding machines that allow for high movement speed is on the rise, as high speeds are critical in terms of changeover times and are needed for energy-efficient and strong welding of high-performance plastics.
For this reason, certain leading-edge IR welding systems come equipped with linear motors, which are characterized by a high degree of accuracy, low maintenance and low-noise operation. These motors guarantee high precision through the retrieval of actual values from the route, allowing any slips of the drive train, e.g. the gear rack, to be completely eliminated.
In combination with this, IR emitters in the system only are switched on during the brief heating time cycle, allowing for lower consumption of resources and energy. This results in optimized parameter and control options that allow manufacturers to set the optimum movement and temperature values for the thermoplastic to be welded. This provides maximum strength of the welded joint, with a high degree of repeat accuracy.
Further, monitoring the temperatures that occur on the surface of joining partners when it comes to thermoplastic manufacturing is of high importance for quality assurance. Certain IR welding machines available today use thermal imaging for this task. Very small, light cameras, which are integrated into the machines, are used to guarantee complete process monitoring and documentation at all times. Data is transmitted to super ordinate systems so that it also can effectively be used for remote maintenance.
The control technology of such a system also can be perfected so that compensation of part tolerances within the IR welding process is possible. This is particularly advantageous in the case of welding gas- and liquid-ducting systems.
Dave Clothier is the technical sales manager for FRIMO, Inc. FRIMO is one of the leading developers and providers of system solutions for the manufacture of high-quality plastic components. FRIMOs portfolio for the plastics processing industries covers an extremely wide range of technologies, and the company offers its customers tailor-made tools, machinery and systems as separate or turnkey solutions from a single source. In order to meet the growing IR welding trend, FRIMO has installed its JoinLine IR Highspeed infrared welding machine at several technical center locations for its customers. The JoinLine is able to attain processing speeds – for both large and small components – that were previously unachievable in the market. For more information, visit www.frimo.com/en/.
————————- Q&A: IML-I vs. IML-T 1 – Despite showing growth in Europe, the use of thermoformed in-mold labeling is limited in the US, with only one molding company embracing the technology so far. Many believe IML-I and IML-T are competing for many of the same packaging applications. by Roman Artz, Inland Label
At the 2013 In-Mold Decorating Association (IMDA) Symposium, held in October in Chicago, IL, workshops were held in which discussions centered on the advantages of injection in-mold labeling (IML-I) and thermoformed in-mold labeling (IML-T). The premise was that containers made by IML-I and IML-T are competing for many of the same packaging applications. In this Q&A, discussion points from the symposium are addressed.
Question: Why is IML-T use limited in North America?
Answer: At the present time, only one molding company in the US has embraced the technology – Tech II, located in Springfield, OH. Yet, it is an IML technology that is showing growth in Europe. Why the disparity in North American adoption?
Many of the larger molders in North America have devoted resources to IML-I and have gone through the maturation process with that process. They may not want to take on the challenge of being first with a new – at least to North America – labeling technology. Similar to the development of IML-I in North America, the consensus during the discussion was that the smaller, more entrepreneurial molders would drive IML-T development to begin with and, as it developed, the larger molders would take it on.
Question: In what area does IML-T have an advantage over IML-I?
Answer: In the first session, the IMDA Symposium attendees were fortunate to have Michael Provini, sales manager from Illig LP, USA, provide some insight into the advantages and disadvantages between IML -I and IML-T from his perspective. According to Provini, IML-T is the more ideal technology for thin wall containers and has faster throughput over IML-I for thin wall applications.
Illig has three systems in North America, and each system can output 27,000 parts per hour. The equipment has good “adaptability” and easy change-out for different labels. Tools also can be easily changed. Container size is limited when compared to IML-I, with the largest size for IML-T being the Eurotub. The cost of an IML-T system can run from about $1.3MM to $1.4MM and up, not including the tool.
Question: What are the cycle time comparisons for IML-T vs. IML-I?
Answer: For short production runs, the belief is that IML-I is perhaps better suited than IML-T because set-up is “not as intensive” for IML-I. Like IML-I, IML-T cycle times vary depending upon production factors: i.e., size of part, number of cavities, wall thickness, etc. Incorporating labeling into thermoforming can double the cycle time for IML-T. Commonly, cycle times for injection molding do not increase to that degree when including the labeling process.
Part of the reason for the increase in cycle time for IML-T vs. IML-I comes from the fact that often there is at least one, if not two, additional steps in the transfer process from picking the label out of the label basket to placing the label in the mold for IML-T. This additional step in the transfer process for IML-T can result in a higher degree of variation in label placement. However, improvement in label placement for IML-T is being addressed.
Question: How are label substrates different for IML-T vs. IML-I?
Answer: Because IML-T involves both lower heat and less air pressure in the molding process than IML-I, label substrate requirements are different for the two molding methods.
In order for the label to bond to the part during thermoforming, label substrates for IML-T require a lower melt point. Therefore, issues can arise when the mold temperature is too low, resulting in poor label adhesion to the part, or when temperature is too high, resulting in the label melting.
The use of less air pressure in the thermoforming process than what is employed in injection molding also can present a challenge to the IML-T labeling process. Air often can be trapped between the label and the thermoform plastic sheet, requiring a way to evacuate the air in order to prevent air pockets or “blisters” trapped between the label and the formed part. Substrate suppliers and label converters are both employing different methods to address this issue.
Since label substrates do need to be engineered specifically for the unique requirements for IML-T, and since there is relatively low demand for IML-T labels at this time in North America as compared to label demand for IML-I, IML-T substrates are currently produced only in Europe. Treofan offers a 60micron cavitated PP material that is commercial in both Europe and North America. Taghleef offers a 65micron cavitated material that is commercial in Europe and soon will be commercialized in North America. Both Innovia and Yupo are in development with their IML-T substrate offerings.
Question: Is IML-I or IML-T more suitable for food packaging?
Answer: Discussions then moved to the development of oxygen barrier packaging and whether IML-I or IML-T may be the better solution to address the growing demands for this type of packaging. Label converters and some molders in the sessions voiced their concerns regarding the in-mold label being the functional barrier for barrier IML, since the label would need to maintain 100-percent seaming integrity to be compliant as the barrier. Could this be verified with vision systems? What would be considered a viable scrap rate for non-compliant seams; and who would be liable if non-conforming labeled containers did make it to the retail shelf? These were all brought up as hurdles for IML-I.
On the other hand, since functional barrier properties can be employed more uniformly in the thermoform plastic rolls, the label substrate would not need to be the functional barrier for IML-T. Consensus among the participants was that barrier IML-T may be a more cohesive solution for shelf-stable food packaging.
Thank you to Roman Artz, Inland Label, for reporting on these IMDA Symposium discussions. For over 65 years, Inland Label has been transforming the packaging industry for the beverage, food and consumer products markets. A family-owned company supplying innovative solutions to customers worldwide, Inland Label is a premier Cut and Stack label producer and a leading qualified supplier of the North American injection in-mold labels. The companys product offering also includes high-performance pressure-sensitive, blow mold and roll-fed shrink labels. For more information, call 608.788.5800 or visit www.inlandlabel.com.
The 2014 IMDA Symposium will take place Oct. 22-23 at the Doubletree Chicago North Shore Conference Center, Skokie, IL. For more information, visit www.imdassociation.com.
————————- Gas-Phase Surface Pretreatments for Plastics Adhesion 1 – Among pretreatments, “gas-phase surface oxidation” processes are proven highly effective, economical and environmentally safe, but the selection of which method is best for an application can be challenging. by Scott Sabreen, The Sabreen Group, Inc.
Surface pretreatments are used to promote adhesion between difficult-to-bond plastic substrates and adhesives, coatings and inks. Among pretreatments, “gas-phase surface oxidation” processes are proven highly effective, economical and environmentally safe. The selection of which method is best for any given application can be challenging, in part, due to misconceptions and confusing terminology. Lets examine unbiased facts and debunk common myths.
Why is pretreatment necessary?
Its important to understand why pretreatments are needed and the mechanisms through which they improve adhesion bond strength. The underlying reasons why many plastics are difficult to bond are because they are hydrophobic non-polar materials, chemically inert and possess poor surface wettability (i.e., low surface energy). While these performance properties are ideal for designers, they are the nemesis for manufacturers needing to bond these materials. As a general rule, acceptable adhesion is achieved when the surface energy of the plastic substrate is approximately 8-10 dynes/cm greater than the surface tension of the liquid adhesive, coating or ink. In this situation, the liquid is said to “wet out” or adhere to the surface. A method for measuring surface energy “wetting” is the use of calibrated dyne solutions in accordance with ASTM D2578.
Gas-phase pretreatment methods
Widely used “gas-phase surface oxidation” pretreatments include electrical corona discharge, electrical atmospheric plasma, electrical air plasma, flame plasma and low-pressure RF cold gas. These processes are characterized by their ability to generate “gas plasma,” an extremely reactive gas consisting of free electrons, positive ions and other species. Chemical surface functionalization also occurs. In the science of physics, the mechanisms in which these plasmas are generated are different, but their effects on surface wettability are similar.
Classical Electrical Corona Discharge is obtained using a generator and electrode(s) connected to a high-voltage source, a counter electrode at potential zero and a dielectric used as a barrier. That is, a high-frequency, high-voltage discharge (step up transformer) creating a potential difference between two points requiring earth ground 35+kV and 20-25kHz. Custom electrode configurations allow for treating many different surface geometries – flat, contoured, recessed, isolated, etc. One application example is a corona discharge treating system for electrical connectors in which a combination of pin and ball electrodes concomitantly treats 3D small diameter holes and flat exterior surfaces, US Patent US5051586 (1991). Ozone is produced in the plasma region as a result of the electrical discharge. Corona discharge has virtually no cleaning capabilities.
Myth: Atmospheric plasma is a low-cost replacement technology for corona discharge.
Fact: Corona discharge often is more effective for treating larger surface areas and greater depth.
Atmospheric Plasma or Electrical Blown Ion Plasma (also termed Focused Corona Plasma) utilizes a single narrow nozzle electrode, powered by an electrical generator and step-up transformer, and high pressurized air in which intense focused plasma is generated within the treatment head and streams outward. This pretreatment process can clean dirt, debris and some hydrocarbons from the substrate, but not most silicones and slip agents. New research indicates that fine etching of the surface can create new topographies for increased mechanical bonding. Ozone is not a byproduct, but nitrogen oxides (NOx) are produced, which may have deceivingly similar odor.
Myth: Atmospheric plasma is electrically potential-free.
Fact: Atmospheric plasma is better characterized as “low potential” unless definitively proven to be zero on any specific application. There are performance differences between equipment manufacturers.
Electrical “Air Plasma” is a corona discharge spot treatment (also termed blown air plasma/forced air corona/blown arc). This treatment head consists of two hook electrodes in close proximity to each other connected to a high-voltage transformer generating an electric arc of approximately 7-12 kV, lower frequency 50-60 cycles/sec (relative to electrical corona discharge). Then using forced air, a continuous electric arc produces a corona discharge, “plasma.” No positive ground is needed. This pretreatment process has virtually no cleaning capabilities. Ozone is produced.
Myth: Corona discharge spot treatment yields longer shelf life than flaming.
Fact: Documented scholarly studies show flame plasma on polyolefins produces longer post-treatment shelf life, due to its relatively shallower depth of treatment.
Flame Plasma Treatment uses the highly reactive species present in the combustion of air and hydrocarbon gas (to create the plasma). While flame treatment is exothermic, heat does not create the chemical functionality and improved surface wetting. Flaming will clean dirt, debris and some hydrocarbons from the substrate. Flaming will not remove silicones, mold releases and slip agents. Flame treatment can impart higher wetting, oxidation and shelf-life than electrical pretreatments due to its relative shallower depth of treatment from the surface, 5-10nm. Ozone is not produced. When procuring flame treatment burners, compare ribbon versus drilled port and the benefits of zero balanced regulators.
Myth: Flame treating is unsafe.
Fact: For decades, flame treating has been used as a safe and effective technique across many industries. Criticism arises from competitive equipment manufacturers.
Cold Gas Plasma, also termed “Low Pressure Cold Gas Plasma,” is conducted in an enclosed evacuated chamber, in comparison to atmospheric (air) surface pretreatment methods. Industrial-grade 100-percent Oxygen gas (O2) commonly is used. Gas is released into the chamber under a partial vacuum and subjected to an RF electrical field. It is the response of the highly reactive species generated with the polymers placed in the plasma field, on inner conductive electrode aluminum shelves or cage, breaking molecular bonds that result in cleaning and chemical/physical modifications (including an increase in surface roughness, which improves mechanical bonding). A significant benefit of cold gas plasma processes is the removal of hydrocarbons, thereby eliminating solvent cleaning. Atmospheric pretreatments do not remove/clean all poly-aromatic hydrocarbons, so solvent cleaning (prior to pretreatment) may be necessary.
Myth: Cold gas plasma batch processing is too slow compared to inline treatment methods.
Fact: Large volumes of parts often can be pretreated (batch) and fed into automated assembly operations; thereby, no additional processing is needed. Cold gas plasma-treated parts tend to demonstrate the highest quality treatment and longer shelf-life. Criticism arises from competitive equipment manufacturers.
Selecting a pretreatment method
Recognize that each method is application-specific and possesses unique advantages and potential limitations. Consider the following factors:
- Polymers react differently to oxidation processes. The type of polymeric substrate and its end use performance requirements are critical in determining the selection of pretreatment method.
- Is the substrate (product to be treated) conductive? For example, unassembled plastic electronic connector bodies – without metal contact pins – can be treated electrically; whereas, assembled connectors may experience electrical arcing problems.
- Part geometry – Flat surfaces easily are treated compared to deep recesses, extreme tapers and other irregularities. Wetting tests are difficult to conduct in small areas and on heavily textured surfaces.
- Material handling automation – Conductive belts and chains may cause electrical arcing with classical electrical corona discharge and spot treaters. Alternatively, consider using flame, cold gas plasma or low potential atmospheric plasma.
- Avoid overtreatment. Excessive plasma-oxidized surfaces may deleteriously affect downstream assembly processes such as poor heat sealing/welding.
- All pretreatment equipment is NOT created equal! Examine the quality of constructed systems in action. For electrical treatment processes, observe the uniformity of the plasma discharge; for flame treatment, consider the differences between ribbon versus drilled port burners and combustion system components; for cold gas plasma, examine the quality of the chamber construction, electrode shelves and particularly the manufacturer of the vacuum pump.
Plasma-treated surfaces age at different rates and to varying extents relative to factors with the surrounding environment. Variation in temperature and humidity can affect the quality and uniformity of treatment.
Scott R. Sabreen is founder and president of The Sabreen Group, Inc., an engineering company specializing in secondary plastics manufacturing processes – surface pretreatments, bonding, decorating and finishing, laser marking and product security. He has been developing new technologies and solving manufacturing problems for over 25 years. For more information, call 972.820.6777.
————————- Hot Stamping for Three-Dimensional Parts 1 – The 3DHS machine employs a vacuum process to pull the foil over the part before a heated die ensures adhesion. 2 – The 3DHS process allows a part to be coated with a metallic, patterned or pigmented foil. by Allan Quimby KURZ Transfer Products, L.P.
At K 2013, the triennial international trade fair for plastics and rubber, held in Dusseldorf, Germany, in October, the company Leonhard Kurz, represented in the US by KURZ Transfer Products, L.P., lauched its patented 3DHS finishing process. 3DHS is an abbreviation for three-dimensional (3D) hot stamping. Visitors to the KURZ booth were able to see a 3DHS machine in action as it was used to partially coat an automotive air vent panel with a chrome foil. The special characteristic of this specific decoration application was that the air vent had a pronounced 3D geometry that would not have been able to be coated in a conventional hot stamping process.
Optimal for decorating thin or moderately-sized parts, the 3DHS process utilizes three components that have been tailored to work together: a special hot stamping foil, a 3DHS die system and the 3DHS machine. The hot stamping foil is available as a true-chrome coating, as well as in a range of metallic tones, a variety of brushed designs and a large selection of pigmented colors.
Advantages to 3D hot stamping
In the past, plastic elements with a curved part geometry, such as the automotive air vent panel demonstrated at K 2013, typically have been decorated by means of galvanization, which requires two injection-molded parts: an undecorated base component and a ring galvanized with chrome that is mounted onto the air vent. The 3DHS process, however, allows a single-component panel to be partially coated with a metallic, patterned or pigmented foil. This finishing method eliminates the need for an injection mold, along with the associated molding operation and assembly step and, therefore, offers significant cost advantages.
The alternative decoration solutions used to achieve a metallic finish, such as galvanizing a single-piece component over the entire surface, also would be more expensive due to the larger coating area.
A further advantage of the 3DHS technology is that it is more environmentally friendly and versatile since design changeovers can be performed simply by exchanging the hot stamping foil. Color changes in chrome plating require a change and disposal of the plating bath, which typically consists of hazardous solutions – either a chromic acid solution or a less toxic solution based on trivalent chromium salts. The traditional metalizing process involves application guns and either combustible gasses or compressed air. The 3DHS is a dry and solvent-free process that makes a spraying tool and a spray procedure unnecessary, which again leads to cost savings.
The 3D hot stamping process
The 3DHS coating process requires three components that have been optimally tailored to one another: a special hot stamping foil, a 3DHS die system and the 3DHS machine. The hot stamping foil developed by KURZ has been specially formulated to meet the requirements of three-dimensional decoration. It has a high elasticity, which enables it to be thermally shaped to match the geometry of the plastic part in a work operation prior to the stamping process.
In a normal hot stamping process with heat and pressure, pressure is applied in a vertical motion to the foil and the substrate to make a transfer. In this application, a vacuum is pulled down over the foil and the foil is pre-heated to give it the elasticity it needs. Then the vacuum is pulled even tighter over the part, and a heated die is brought down to ensure adhesion and make the impression.
One of the main advantages of the process is the ability to avoid wrinkles. In the past, if a designer wanted to decorate the outer ring of a part, that normally only could be done if the part geometry was flat and consistent. In traditional hot stamping, wrinkles can become an issue if the part geometry has not been designed for a suitable hot stamp, but the vacuum and the flexibility of the foil in the 3DHS process eliminates that concern.
The cycle time for the 3DHS process is longer than traditional hot stamping because of the drawing of the vacuum, but the amount of extra time necessary is project- and size-dependent. Cycle time, however, as it relates to alternative decoration mediums, is very competitive. It often could be considered to be faster because of the modular design and ability to place the decoration inline in the manufacturing process.
Decorative options for 3D parts
This technology gives designers a little more freedom of design. They can think in three-dimensional shapes and still avoid some of the hazardous processes, such as chrome dipping and plating, by using a hot stamping solution. Studies from KURZ show that 3DHS could be a fraction of the cost of a traditional coating or plating process. This is, of course, part size- and volume-dependent. Applications could include automotive interior and exterior applications, household appliances, electronics, consumer goods, health and beauty aids and many others.
In addition, KURZ can support chrome foils that are 100-percent corrosion-resistant and are used on many outdoor and automotive applications. The wear resistance also is built into the construction of the foils, with robust topcoats to pass the most difficult wear and abrasion testing.
The key is that each stamping solution is specifically designed to the specific application requirements. An engineering study is performed to assist the customer in designing the part geometry, ensuring that it lends itself to this decorating process. The tooling and machine solution is then created to match the application and required results. The foils are specially designed to essentially stretch around the part, and the color or pattern is created to the customer specifications. With the 3DHS process, parts with a pronounced 3D geometry that would not have been able to be coated in a conventional hot stamping process now have a new decorating option.
Allan Quimby is the area sales and marketing manager – plastics for KURZ Transfer Products, L.P. KURZ is a major international supplier of hot and cold stamping technology. The company has more than 4,200 employees, as well as nine production facilities located throughout Europe, the United States and the Pacific region. KURZ hot stamping foils are utilized on a wide assortment of products. These include packaging, greeting cards, electronic devices, household appliances, automotive parts and numerous other items. In addition to foils, KURZ offers a wide range of other products such as stamping tools and machines. It also has the expertise and logistical support necessary to satisfy all the demands of effective, high-volume foil production. For more information, call 800.950.3645 or visit www.kurzusa.com.
————————- Cleanroom Considerations by Ron Kosmalski, Clean Air Technology, Inc.
The health care community is a significant consumer of plastic products and components. Products ranging from syringes and IV bags to medical grade tubing and implantable devices now rely on injection molders to meet demand.
Manufacturers hoping to enter that arena already may have mastered product quality and production efficiency targets, but frequently are challenged with another set of performance goals… meeting air cleanliness standards.
Understanding cleanroom classifications
By definition, a cleanroom is a pre-defined room or area where the volume of particulates as small as 0.5 microns in size is reduced through filtration and air exchanges. Instrumentation is used to sample volumes of air within the environment to qualify clean classifications as defined by global ISO standards. Control of temperature, humidity and pressure are additional environmental parameters frequently measured within cleanrooms.
The cleanliness classifications are well-documented and based on identification of six categories of sizes, ranging from sub-micron sized particles of 0.1 and up to 5 microns in size. A micron is one millionth of a meter. We are unable to see anything this small without the aid of microscopes, but if we could set particles that are one micron in size side-by-side, we would need 25,400 of them to span one inch. The cross section of a typical strand of hair is 35 to 40 microns in size, so when sub-micron-sized particles need to be controlled, High Efficiency Particulate Arrestance (HEPA) filters are required. There are plenty of other acronyms used, but the point is: this is a special, clean environment. These lightweight particles easily are suspended and influenced by air currents. Particle counters with laser light beams are used to qualify the ISO-clean manufacturing environment by identification of the quantity of particles present in a sampled volume of air. These are documented as the quantity found in a cubic meter of air within the environment.
Designing a cleanroom to meet an ISO-8 level means enough air needs to be delivered through enough filters to reduce the particle count to 832,000 one-micron-sized particles in a cubic meter of air (a sample equivalent to approximately 35 cubic feet).
Some plastic products can be terminally sterilized after manufacturing, but others are unable to withstand the sterilization methods effectively and must be produced in clean environments. Cleanrooms are not a substitute for sterilization, but they complement the process by reducing particulates that accumulate on the product or package surface.
If the product that warrants the ISO-classified environment can be produced in its entirety within a single line or similarly confined area, a cleanroom envelope can be built around that line. If this is not practical due to the multiple processing requirements of a product, the feasibility of upgrading the entire production environment may need to be evaluated.
Designing a cleanroom
Aside from the cost for the project, key considerations when planning a cleanroom are
- cleanliness and environmental goals,
- opportunities for effective air distribution and
- supporting infrastructure.
1. Environmental goals
Unless defined by the end user or final product packager, the actual cleanroom classification selected by the manufacturer may be determined by the nature of the product, the manufacturing process itself and the potential for effective sterilization. At the minimum, molding production facilities designed and built today will meet an ISO-9 air cleanliness classification.
Areas where specific molding operations take place frequently are designed to meet an ISO-8 or ISO-7 classification. If a particular material is adversely affected by sterilization procedures or if downstream assembly adds to the complexity, a more critical manufacturing environment meeting ISO-6 or ISO-5 cleanliness levels may be specified.
Temperature and humidity levels within the manufacturing environment should be identified as part of the cleanroom design. Medical grade component manufacturers should be able to obtain qualification data from the end user and, once identified, the air system can be designed to meet the specific temperature, humidity and filtration goals.
2. Effective air distribution
Cleanrooms are defined areas where increased air exchanges and high-efficiency filters combine to reduce airborne contamination within the designated space. Dedicated air handling systems and HEPA filtration components are used for this purpose.
The nature of molding operations combines electrical, pneumatic and mechanical functions that generate particulates and turbulence. The cleanroom or designated clean area should be designed to bathe the product and process in HEPA-filtered airflow and to reduce the opportunities for turbulence.
Effective removal of the particle-laden air steam is equally as important as directing the airflow onto the critical zone. This can be accomplished by utilizing low-wall air return ducts adjacent to the injection molding machine. Making provisions for the specially conditioned clean airflow to find a route away from the critical zone will help minimize the time these lightweight contaminants will be exposed to the product. This “conditioned” air can be returned to the cleanroom air handler for efficient operation. The physical dynamics of the recirculating air system need to be considered, along with the support utilities and material handling requirements of the process line.
An air return plenum is a key design element in building an effective recirculating airflow system. The plenum is a double-sided space that can be sealed to serve as a duct or airway within the room or space adjacent to the clean zone.
In existing facilities, adding/building plenums above and near the process line may be too complicated to achieve. Injection molding lines require numerous utility/service connections for electrical, chilled water supply/return, compressed air, etc. These frequently are routed through the facility and then dropped vertically to the molding machine. In addition, overhead cranes frequently traverse the manufacturing floor, compounding the issues in determining a layout for the ideal air distribution network. Depending on the logistics, it may be impractical to locate an air return plenum above, below or around this collection of service utilities and equipment, so dedicated low-wall air return ducts need to be routed throughout the space.
All of these factors need to be addressed when developing the floor plan for an injection molding facility.
3. Supporting infrastructure
New construction simplifies planning for the cleanroom. A reduced environmental envelope can be considered if planning a new facility, and a favorable location for the cleanroom can be chosen to take advantage of the proximity to the buildings mechanical and/or electrical rooms and platforms. Process equipment layout can be orientated to enable the use of portable cranes and hoists for die changes and other service requirements, and utility distribution can be routed to enable space for the air supply and return system ductwork.
The area for the clean operations should be away from material handling and high traffic aisles and also away from doors that frequently are opening to the outside. Cleanrooms should be located where a level, cured floor can receive a high-quality sealer and coating to ensure the surface cannot degrade and contribute particulates to the environment.
Existing facilities with molding operations rarely afford space for optimal air flow and distribution. Portable air projectors or scrubbers can be added to improve the air quality by reducing the particulate concentrations of the air near specific machines or operations, and emphasis must be placed on cleaning and turbulence. Machine surfaces near the platens should be cleaned, and utility lines with related fittings, gages and support members should be cleaned and maintained. Material handling equipment and personnel activities adjacent to the molding operation should be minimized or altered where possible to reduce disruptive air flow patterns nearby, and the floor should be effectively sealed.
Planning a cleanroom
Is extra cooling needed? Is humidity control a factor? How clean do we need to be? What level of gowning will be sufficient? How can we get from where we are to where we need to be?
The answers to those questions can help you proceed down the right path. Find the answers by doing your research, asking your customer and contacting industry experts for their insights and recommendations. You may be able to consider something as simple as a portable softwall cleanroom or air projector, or you may need something as complex as a dedicated multi-suite manufacturing environment with independent temperature, humidity and pressurization controls.
When in doubt, lay it out. Just like measuring furniture or appliances when renovating a room in our house, making a floor plan is the best start for any cleanroom project. The first priority always is safety. Ensure there are adequate paths or provisions for personnel egress if they need to make an emergency exit. Ensure there is adequate room for personnel to perform the loading, staging, retrieval and cartage of materials or other process-driven functions that require human interface.
Then, add the support services that make the production process possible. Determine the route for utilities, cranes or other lifting mechanisms, material carts, totes and relevant transfer components. Consider options that can enable a clear path for air supply and return requirements.
Include additional space adjacent to the cleanroom for the air handling system, and designate additional space for housekeeping supplies or potential gown-up/staging requirements.
Finally, enlist the services of a qualified and experienced cleanroom design/fabricator. Every sheet metal and air conditioning contractor will convince you that they can make this work, but due to the complexities involved, rely on the expertise of the companies that do this for a living. Work with a company that has fabrication capabilities to help make your investment a success from the start.