Cleanroom garment makers respond to global pressures and expanding markets by making steady improvements
by Chris Anderson
In the past five years, changes to cleanroom garments and the materials used to construct them have followed a simple formula: Make steady improvements on what's available.
Though manufacturers such as Burlington, DuPont, Stern and Precision Fabric Group grab much of this business, overseas competitors, especially in woven materials, have begun to pressure these stalwarts both in price and innovation.
“I definitely think we are going to see a globalization of the market,” says John Smith of Precision Fabric Group (PFG; Greensboro, NC). “All the major manufacturers of fabric sell into Europe and Asia, and there are also many new fabrics coming into this country from Asia.”
For end-users, the issues have changed little: They want fabrics that provide a better barrier with enhanced ESD properties and less particle generation. Not so long ago fabrics produced for use in different industries differed accordingly. But today's more sophisticated manufacturing environments means pharmaceutical and semiconductor workers may often be wearing garments made of the same material.
Your fabric, my fabric, everybody's fabric
A little more than 10 years ago, the major users of cleanroom garments, the semiconductor and pharmaceutical industries and hospitals, used garments constructed of fabrics that differed significantly.
Today, these three user groups all look for fabrics that provide an effective barrier between the product and the worker, are constructed of polyester for its low particle generation and effective ESD properties.
End users want garment fabrics that provide a better barrier with enhanced ESD properties and less particle generation. Photo taken at RF Micro Devices courtesy of PFG (Greensboro, NC)
“I would say that there has been a convergence of what different industries are looking for in their garments,” says Jonathan Harris, president of garment maker CleanWear Products Inc. (Toronto). “But there are also such coatings as Teflon to enhance certain characteristics for the fabrics depending on each application.”
ESD continues to be a major concern to all kinds of users. “That is probably the one area where we see most of the demands coming from end-users,” says Anderson Hostetler, vice president of the barrier products for Burlington Industries Inc. (Greensboro, NC), producer of the C3, C4 and C5 lines of fabrics. “They are just demanding higher ESD properties.”
ESD has long been important in the electronics industry. In a hospital setting, this property helps produce a more comfortable garment by reducing the static cling. In pharmaceutical manufacturing, it has gained importance simply as another means of preventing unwanted particles from contaminating products. “It's important for people to understand that cleanrooms are designed to control the particles,” says Brad Whitsel, a project management consultant based in Chambersburg, PA. “We don't want them to fly about, and we don't want them to snap onto the surface of a garment carrying a charge.”
Some newer woven fabrics have a small pore size to keep fewer and smaller particles from getting into a clean environment. Photo taken at RF Micro Devices courtesy of PFG (Greensboro, NC)
Today's fabrics also sport much tighter weaves that have significantly decreased the size of the pores within the fabric. These changes have been spurred by the increasingly smaller geometries within the electronics and semiconductor industries. The equation here is pretty simple: The smaller the pore size, the more particles it catches from the human body and the clothes worn by the workerthe result being fewer and smaller particles finding their way into the clean environment.
But some in the industry wonder whether the rush to decrease the pore sizes might be overkill. “Let's face it, the performance of the product is only as good as the people using it,” says Bob Spector, director of sales for Prudential Cleanroom Services (Austin, TX), and president of the IEST. “There are a lot of products out there that have been on the market for a while that will still do the job. It's like when you buy a car, you don't always need to buy the Cadillac.”
Though he might disagree with Spector's assertion, Whitsel says since the introduction of the Integrity line of fabrics by PFG, there might not be a way to significantly reduce pore sizes. “I'm not sure, exactly, where woven technology can go from here,” he says. “The Integrity line has introduced to the market a woven fabric that acts like a membrane.”
Wither the nonwovens?
When it comes to absolutely, positively preventing the movement of any particles from the worker to the environment, nothing quite performs like a nonwoven. The characteristics of garments made of nonwoven materials can vary so greatly from their woven competitors that appropriate uses also vary.
Garments made of nonwoven fibers are not particularly durable. For that reason, they are considered single-use or limited-use products.
Nonwovens are a lock for applications where it is essential to protect workers from the materials they are handling. “By their very nature, non-woven materials can be made absolutely water proof and gas proof, so it can totally isolate the wearer from the environment,” says
Ted Wirtz, president of the Association of the Nonwoven Fabrics Industry (Cary, NC). “That's something you just can't do with a woven fabric.”
Pete Gabele, cleanroom segment manager for DuPont Protective Apparel (Wilmington, DE), says Tyvek, the company's nonwoven, has found strong markets in the biotech and pharmaceutical industry “where clean and sterile is the first priority.”
Other customers that choose single-use garments include small manufacturing facilities which are not able to meet cost effective apparel volumes or are not located near a cleanroom laundry.
Because they are disposable and have a low cost, garments made of nonwoven materials are also the apparel of choice for visitor gowns, Gabele notes.
Still, nonwoven materials can find it difficult to compete in environments where ESD is critically important. Wirtz notes that new processes allow for treatments of nonwoven materials to make them less likely to pick up an electrical charge.
But CleanWear's Harris says that's a far cry from being static dissipative. “People would like to tell you that their [nonwoven] material has been treated to prevent it from picking up a charge,” he says. “But that doesn't give it ESD properties. If it picks up a charge somehow, it's not able to get rid of it.”
Regardless, the market for nonwovens is strong and is not expected to diminish. “The new and emerging industries that continue to have more critical barrier and cleanliness demands have quickly seen the benefits of using apparel made of Tyvek,” says Gabele.
The automotive market has been a boon to many in the garment business. In the past five years, the auto industry has incorporated more and more clean technology into a variety of manufacturing processes, particularly in its paint rooms. As the industry looks to apply thinner, stronger layers of paint to its products, it has found that even very small particles are enough to cause an imperfection in a paint's finish.
“The auto industry has realized there can be savings in having a cleaner environment as it can reduce the need to repaint,” says Harris.
But providing garments for the automotive workers is not as easy as pulling something off the rack that serves the semiconductor and pharmaceutical industries. “One of the things the workers want in the auto industry are more comfortable garments,” says Rob Nightingale, of Cleanroom Garments (Toronto). “Because they are not used to wearing these garments, the workers don't like them.”
One solution that Nightingale found is to provide garments made of microdenier polyester, a much more pliable and supple material than tightly woven polyester fabrics. But it is not the be-all, end-all solution. “Microdenier wears much quicker than other fabrics,” says Nightingale. “It has some greater issues in terms of shedding, as wash after wash it produces more fibers.”
In addition to the comfort issues, many in the industry see that procedures within auto plants have not caught up to the technology of the garments some of its workers wear. “Look at a typical locker room in an auto factory and it can be [a long distance] from where the paint room is,” says Harris. “And the workers will change into their garments and walk all the way through the factory with them unzipped before they finally start painting.”
Another market with potential, industry insiders say, is food manufacturing. Yet the jury is still out as to whether this market will catch fire. “There are some signs that this might be the next industry to really take off,” says Harris. “But it's not a huge stampede.”
The reasons for food manufacturers to move toward cleanroom-like environments include reduction and control of foodborne pathogens, such as E. coli, and to decrease the amount of preservative currently needed to prolong shelf life.
But food companies will need to see the financial benefits before making that kind of wholesale change, says Spector of Prudential Cleanroom Services. “I'm not sure they are going to rush into it at all,” Spector says.
“If it is not going to improve the overall operation and provide a savings to the company, why adopt it?”
The learning should never stop
As with most facets of the cleanroom industry, the workers in the trenches need to receive continuing training to ensure the correct use of cleanroom garments. Garment and fabric makers can also do their part by educating the end-users about the capabilities of the fabrics on the market as well as their proper uses.
“The end-users don't always know what they want, or what is appropriate for their operation,” says Spector. “The most important thing we can do for a customer is to provide them with the most cost-effective solution to suit their particular manufacturing process.”
That process doesn't always include the latest and greatest fabric on the market. “If you are going to pay more for one garment as opposed to another, the real questions the end-user needs to ask is will it significantly increase my yield, or lower the reject rate or whatever measure they use,” says Spector.
Yet once the appropriate garments are put in service, their benefits can unravel if not used properly by the workers.
“There is no question that most workers don't understand the operations of a cleanroom,” says Whitsel. Training of production line workers is the key to making sure that the garments can serve their purpose in the overall cleanroom system. “[The training] all needs to be visual. Until workers can actually see the consequences of their actions they won't understand.”
Spector agrees that companies need to make worker training vital. “Telling a worker to wear a particular garment 'because I says so' isn't the way to go,” he says. “But giving them information that the human hair can range in size from 60 to 110 microns when you are working on things that are 15 microns puts it on a level they can understand.”
Chris Anderson is a freelance writer in Portland, Maine.
Apparel programs: Be aware of what the industry has to offer
by Brad Whitsel, Whitsel Associates Inc.
Most cleanroom apparel service companies have “corestock” programs that feature a standard line of garments. Limited styles and fabrics ease inventory headaches and allow ready-at-hand stocks to be maintained. Prompt program start-up, no delay in outfitting new hires and efficient size changes are a few of the real end-user benefits.
Unfortunately, “corestock” programs often began years ago and are based on older garment designs and fabric technology. Because it is disruptive and complicated to phase in new fabrics and garment designs, and very costly to abandon the thousands of garments a service company has in working inventory across a broad customer base, there is little incentive for the service company to upgrade the program. New customers, therefore, are often aggressively urged into the “corestock” program and existing customers are penalized if they desire to changeeven if their product or process requires it.
When developing or managing a cleanroom apparel program that is appropriate to the application, it is important to be aware of what the industry has to offer, not just what your service company has to offer. Contacting garment and fabric manufacturers to gather information about the latest product innovations is one very good way of assessing the current state of technology. Benchmarking is another way, and of course it can't hurt to discuss your concerns with your present service provider as well as their competition.
A relationship with a cleanroom apparel service company is seldom a partnership of short duration. And because we all know that perpetuation without evolution leads to extinction, make sure you're not dancing with a dinosaur.
Brad Whitsel is president of Whitsel Associates Inc., a project management and consulting firm formed in 1986. Mr. Whitsel is an active member of several industry trade associations and is on the Editorial Advisory Board of the Journal of the Institute of Environmental Sciences and Technology.