With new applications exploding in antimicrobial technology, diagnostic testing, protective apparel, footwear and automotives, nonwovens are taking center stage.
Foss Manufacturing Company, a vertically integrated producer of engineered, nonwoven fabrics and specialty synthetic fibers has developed Fosshield, a fiber technology that contains a unique antimicrobial, antiviral agent that inhibits the growth of destructive bacteria, mold, mildew and other fungi.
Foss has also developed Eco-fi polyester fiber, a unique product that is made from 100% certified recycled plastic polyester bottles. Eco-fi can also be blended with Fosshield antimicrobial fiber technology to create durable and natural antimicrobial fabrics.
Dave Rowell, Foss’ executive vice president explained, “Our antimicrobial fiber is a patented technology of a bicomponent fiber. We put copper and silver ions into the melt stream that makes up the sheath of the fiber. There’s an ionic exchange that happens in the presence of moisture where sodium ions exchange with the copper and silver ions in the fiber. The fiber absorbs the moisture and expels the positively charged copper and silver ions onto the surface of the garment. When those copper and silver ions come in contact with microbes such as bacteria, mold and mildew, they compromise the cell wall of the bacteria and shut down the metabolism of the bacteria. They shut down the digestive, respiratory and reproductive systems. There’s a real synergistic effect using the two copper and silver combined. One of the biggest synergistic effects is the quick speed of the kill rate of the bacteria.”
Applications for Fosshield include filtration, face masks, socks, bedding, upholstery, wallcoverings, indoor and outdoor carpeting, indoor and outdoor peel and stick tiles and medical (hospital/medical cubicle curtains, uniforms and lab coats).
“We’re also working with the military to get it in some of the apparel for the soldiers and are working with companies like Glen Raven to get into some of their indoor-outdoor awnings,” said Mr. Rowell.
No stranger to the green movement, Eco-fi fiber technology is an environmentally friendly development from Foss. “We are manufacturing our fibers using recycled bottles, and we are changing a lot of our nonwoven fabrics over to 100% post consumer recycled polyester content. The whole sustainability story is in the forefront. People are starting to understand more about recycling. The recycled bottles are high quality polyester. It’s a great polyester resin and we’re spinning and making polyester fiber out of it and needlepunching it into a majority of the different fabrics. We are putting Ecofi PET into all applications possible including OEM auto, mHrv, marine craft felts, apparel and agriculture,” said Mr. Rowell.
Lydall is taking nonwovens applications to new heights in the diagnostic testing arena with its LyPore glass fiber microglass media. These materials are made with very fine strands of borosilicate glass which provide a prefiltration step and/or a reaction pad for a chemical reaction to happen
Jack Ramsay, senior manager at Lydall, said, “The idea of a diagnostic test is to transport a sample liquid, such as urine, blood and saliva and to pick out specific things like protein that indicate a certain condition, disease or illness, isolate it with chemistry and to move it to a point on the test where it indicates there is a presence of this protein or antigen. The materials each perform a different task— either there’s a transport, a filter or as a final destination to immobilize the protein or antigen you are looking for.”
“With diagnostic tests, accuracy is reaction time. Typically, you have an antibody that is immobilized or is stuck on to the material and when the antigen from the sample comes across they combine. Sometimes the reaction will take a little bit longer so a tighter material would slow down wicking or the reaction process to the test. When you are looking at sexually transmitted diseases or infectious diseases, it can demand a different type of material than a standard material that would have to do with thickness or density,” said Mr. Ramsay.
Pointing out that testing for infectious and sexually transmitted diseases in third world countries requires an expensive test that is unaffordable in these countries, Mr. Ramsay said, “You need highly accurate materials and chemistries that are very low priced to be able to test the population to decrease epidemics. You have to identify the carriers and to do that you have to do a lot of testing. It’s important to use the optimized chemistry and optimized material to get the best test for the least amount of money. LyPore is very cost effective. Diseases like malaria can destroy populations. The more you heal a population, the more effecive you are in removing the disease, the better chance those populations have to move forward and become more independent.”
More New Apps
Texel is a longstanding player delivering novel nonwovens applications that are being used in several sectors including automotive, rugged footwear and protective apparel.
One of these innovative products is dubbed ThermoFit and it is available in synthetic, natural and composite versions.
Gale Shipley, Texel’s sales representative for automotive said, “Texel has the ability to customize products on the needlepunch line to fit unique customer applications. Our ThermoFit product is a proprietary blend of thermoplastic and non-thermoplastic material engineered for enhanced acoustics.”
Applications for ThermoFit’s synthetic product includes automotive exterior wheel well liners, storage compartment, such as the glove compartments and storage bins in trucks, door panels, package trays and dash inserts.
The natural version of ThermoFit can be used in furniture panels and door panels. “We’re seeing applications in outdoor patio panels where some added acoustics are needed to mimimize road noise but still have a decorative effect. A decorative face fabric can be laminated onto the ThermoFit substrate that is both sun-proof and weatherproof,” said Ms. Shipley.
ThermoFit is also used in insulative protective footwear that is worn by hikers, firemen and the military. “We are concentrating on protective and footwear applications. Texel’s ThermoFit and other multi-layer components allow products to breathe and to wick the moisture away from you so you don’t feel sticky after wearing the product for an extended period. Some of the protective apparel is bulky and heavy. If you make it with a nonwoven, you can make it lighter,” said Ms. Shipley.
Thermofit’s composite form can be used to manufacture protective helmets and canoe/kayak hulls. “It can be made in very lightweight versions—300 to 400 grams per square meter,—but can go beyond 2000 gsm. The 2000 gsm and beyond products would be used in panel type applications which require board like features,” said Ms. Shipley.
Injection Mold Barriers
Texel is launching a dual-color injection molded barrier product used in the manufacture of A, B, C pillars of cars. Ms. Shipley said, “We are able to make a single product that is a stratified needlepunch nonwoven that is white on one side and black on the other. When our customer runs dark-colored face-fabric material, they require a black barrier and when they run beige or lighter colored face-fabric material they require white. Normally, they have to order and warehouse two different products. Texel’s dual-colored barrier lowers the customer inventory to one SKU instead of two, thus lowering inventory cost. From a visual standpoint it does what it needs to do whichever application it is being applied to.”
Taking the Foam Out
Texel is also exploring the development of a product to replace foam in some of the thinner foamed areas of the vehicle like headliners. There is a three millimeter foam layer behind the face layer in some vehicles. We are developing a needlepunch nonwoven made with filtration technology to replace the polyurethane foams. This product will eliminate the hazardous components in the foam with something that is more recyclable and environmentally friendly. That’s one of our newer developments in trial stage now,” said Ms. Shipley.
Ahlstrom is taking nonwovens to a new plateau with an application for the beverage industry. According to company spokeswoman Beth Schivley, in 2009, Ahlstrom inaugurated a new infusion line at its Chirnside plant in Scotland which expanded the existing range of traditional heatsealable and non-heatsealable materials produced at the site. It also opened a new chapter in the history of beverage infusion materials.
The new line uses spunmelt technology to produce BioWeb, a lightweight nonwoven web, which provides an environmentally friendly, sustainable and affordable solution for high-end and specialty tea packers, designed for conversion on tea-packing machines that use the more recently developed ultrasonic sealing technology. This packing equipment allows the production of pyramid shaped teabags.
Using renewable biopolymers manufactured from corn starch, BioWeb is biodegradable, compostable and sustainable. The principal ingredient is polylactic acid (PLA), derived from yellow dent corn starch. BioWeb adds value to tea bags and provides the opportunity to create visible and tangible differentiation leading to increased consumer awareness of premium quality tea offerings.
The trend towards the production of premium and specialty teas using larger leaf particles requires filter materials with great transparency and superior taste neutrality, two qualities that clearly distinguish Ahlstrom’s BioWeb from traditional tea bag papers, according to Ms. Schivley.
When it comes to nonwovens in military applications, the U.S. Army is researching a long list of applications.
Stephen Szczesuil, U.S. Army textile technologist in Natick, MA. said, “Our primary goal is to utilize nonwovens as an alternate to woven fabrics to serve as launderable flame resistant uniforms. The use of nonwovens will serve to broaden supply of production, lower costs and hopefully semi-automate the supply basis.”
Military nonwoven applications include the use of disposable garments, non FR bandoleer bags to carry ammunition out to the field, FR shipboard uniforms, coveralls, non FR utility type uniforms, camo FR face masks with use of medical grade silicone gel adhesive, FR helmet covers, FR combat/CB uniforms base liner for FR gloves with cut protective coating or lamination. There is also the potential to apply FR silicone coating for potential lightweight shelters.
“The big advantages to nonwovens are lower cost, higher production rates, ease of processing, no raveling of edges, high breathability, extreme lightweightness to strength ratio, hand, suppleness, abrasion resistance, low shrinkage, printability and other characteristics,” said Mr. Szczesuil.
Mr. Szczesuil continued, “In the military everything is flame resistant now. All the (military) services are now looking at applications for FR combat CB (chemical biological). It will have all of the enhanced protections—water repellent treated, chemically biologically resistant and flame resistant. The army is developing a combat CB uniform using nonwovens in combination with activated carbon. Nonwovens have the capability of offering all these protections.”
Mr. Szczesuil said the research efforts are concentrating on hydroentangled spunlaced nonwovens. He envisions that by June 2010 there will be some large-scale test runs or prototypes. “We’re trying to develop nonwovens so they do have good clothing characteristics, good hand, good drape and a textile hand. If you have a stiff nonwoven, it’s not good. The research and development effort is to get the hand, the durability and all the characteristics so the nonwoven is very similar to a woven. We’ve been dealing with nonwovens and the promise of nonwovens for 20 years. We tried to make tents and uniforms out of it and they all let us down in some respect. I’m seeing the development in leaps and bounds in the nonwovens processing and production capabilities and the equipment is enhanced. Nonwovens usage will definitely grow in the military. It’s on the doorstep.” v