%" m •*^.. ? •^^:; m^ "•~.y.-, .-,. Id X LCI New Synthetic Fibers Come from Natural Sources By Maria C. Thiry, Features Editor n the beginning, textile fibers of applications for synthetic fibers able properties, such abrasion resis- came from the natural world: and their increasing popularity. Cot- tance, stain repellency, and wrinkle animal skins, hair, and wool; silk ton producers decided to fight back. resistance. In addition, according to from silkworms; and plants like Cotton Incorporated's famous market- Wallace, genetic research has gone into a flax, cotton, and hemp. For ing campaign is credited for bringing improving the quality of the fiber it- Icenturies, all textiles came from fibers the public's attention and loyalty self—qualities such as increased that were harvested fron:i a plant, ani- "back to nature." length, and improved strength of the mal, or insect. Then, at the beginning "Cotton is the original high-tech fiber over the last 30 years. "In the of the 20th century, people discovered fiber," says the company's Michelle marketplace, it is important to have a that they could create textile fibers of Wallace. The fiber's material proper- differentiated product," notes Cotton their own. Those early synthetic fibers ties, such as moisture management, Incorporated's Ira Livingston. "We are still originated in a natural source— comfortable hand, and wet tensile continually looking for ways to intro- cellulose from wood pulp—but soon strength contribute to its appeal. The duce cotton that surprises the con- enough in the 1930s, 40s, and 50s, a development of various finishes has sumer. One of those ways is our re- stream of synthetic fibers came on the given cotton fabrics additional favor- search into biogenetics, to enhance scene that owed their origins to chemical plants instead of plants Cotton's Share of Market that could be grown in a field. Percent Apparel & Home Fabrics Now at the beginning of the 21st 75% century, the trend in fiber research ^1961-75 Trend ^Cotton'B Share has come full circle. While the 61% popularity of completely synthetic fibers remains high, in many cases attention is once again being fo- cused on synthetic fibers that come from natural sources. STARTING THE (COnON) BALL ROLLING Once the king of fibers, cotton tex- Sourca: NPD and Traife Data tile fiber usage began to decline in * Endudn Caipat the 1960s and 70s with the growth Cfta/? courtesy of Cotton Incorporated, Used with permtssior}. JANUARY 2004 VVWW.AATCC.ORG feed stocks of high value fiber that do- > not drain the environment and '^^ from multiple rather than singh ^ sources." As well as the plant world, the <. "^al kingdom contains many more pro-"iii sources for fibers that have yet lo be exploited. One of these is chitin, from the waste products of the shellfish indus- try. According to Sam Hudson of North Carolina State University, "Chitin is considered the second most plentiful renewable resource on earth, after cellu- Photos courtesy of Fred Neal and South West Trading Co. Used with permission. lose." The shellfish waste is treated to extract the chitin, like wood chips are cotton and to keep it a brand new treated to extract cellulose fibers in rayon 6000 year old fiber." production. "We have known about Cotton's resurgence has awakened Jonelle Raffino of South West Trading chitin for many years." explains Hudson. researchers to the appeal of natural Co., who markets soy yarns under the "It was first chemically identified in the fiber sources. As well as being a re- trade name of Soy Silk, feels that the early 1800s, but in the last 10-15 years, newable resource and biodegradable, marketplace will be very receptive to interest has been picking up." cotton fibers also have material prop- this fiber. "Consumers are demanding Another "hot" area of fiber research erties that are appealing. And Cotton new ideas and smart ideas. Soy tlber is spider silk. "Spiders have evolved a Incorporated's marketing has ensured satisfies the consumer on a lot of toolkit of as many as seven types of that the marketplace is receptive to levels—it is fabulously soft, reason- silks that they use to construct webs. textiles made from natural fiber ably priced, and appeals to the aware- With over 37.000 described species of sources. "We brought the consumer ness of environmental issues." spiders on the planet and all them pro- back to a 'natural state of mind' with Cargill Dow went back to basics ducing silk, this makes for a wealth of over 30 years of communication," when they developed polylactic acid opportunities for fiber researchers to notes Livingston. "This has opened up fiber (PLA) that they market as Ingeo. bioprospect." says the University of opportunities for other natural-based "PLA was the first generic fiber regis- California—Riverside's Todd fibers." tered by the U.S. Federal Trade Com- Blackledge. mission in almost 50 years." notes BIOPROSPECTING Cargill Dow's Joe Raffo. PLA fibers INTRIGUING POSSIBILITIES Natural fibers are either plant (cellu- are made using lactic acid as the basis For researchers, the allure of these new lose) or animal (protein) based. Ac- for the polymer. The lactic acid comes fiber sources lies not just in their avail- cording to Anil Netravali of Cornell from fermenting natural sugars or ability or sustainability. but in their University, 'There are a lot of plants starches. Ingeo is manufactured using intriguing material properties and pos- we haven't looked at yet," for textile feed corn, but Cargill Dow is develop- sibie applications. "Chitosan (.the fiber fibers. His group is researching the ing a way to use the com stalks—a form of chitin) is not as strong a fiber manufacture of composites using part of the plant usually considered a as cotton or nylon. It is* also sensitive to fibers from various plant sources, waste product. Other such as flax, ramie, pineapple, jute, researchers are look- banana, bamboo, sisal, hemp, and ing into using rice kenaf. starch to manufac- Other groups are promoting soy ture PLA. Sustain- fiber, made from the waste products able PLA fiber of the soybean industry. "Soy fiber is manufacturing from a rediscovered product that has many waste plant material uses," says Barb Keeling of Keeling's is an exciting idea Krafts, who uses soy fiber in her doll for many. According making business. She notes that the to Nexia Biotech's fiber has been around a long time, and Ali Alwattari. "The is only now seeing a resurgence of potential to make interest. "Henry Ford talked of soy fiber from waste fiber in the 1940s. He even had a suit biomass ... could and tie made from woven soy fibers." create big, renewable AATCC REVIEW JANUARY acidity—it can dissolve in an acid ability to wick moisture solution (vinegar can turn it into a like cotton but dry gel). It is also too expensive to quickly like polyester manufacture to compete with rayon make it appealing for as a commodity fiber. However, it is apparel. Low odor an excellent special purpose fiber for retention and UV trans- medical applications," says Hudson. parency (sunlight Among its attractive fiber properties, doesn't degrade it) chitosan is non-allergenic, has ben- make it attractive for eficial bioactivity, and is naturally apparel, carpeting, antimicrobial. "The surface of the home furnishings, and fiber resists bacterial colonization," drapery. "The fiber's says Hudson. "It is being promoted sustainability becomes for odor control because of its anti- a 'throw-in'," says microbial properties." However, Raffo. "People like to chitosan's most useful property is be environmentally that it's haemostatic (efficient at conscious as long as it stopping bleeding). One current ap- doesn't affect price. plication uses chitosan in a Performance is tbe most haemostatic bandage to stop arterial important thing." bleeding. Not only hospitals, but military organizations have keen PERFORMANCE interest in this application. Performance is the attractive feature for Marketability spider silk fibers. Re- According to Raffo, PLA's material searchers are impressed properties enhance its marketability. with its material proper- "Different aspects of the fiber make it ties. According to the useful in different markets." The University of fiber's natural fire retardance makes it Wyoming's Randy Lewis, "Spider ropes (like the cables that stop planes useful for drapery, office panel sys- silk's tensile strength is as high as when they land on aircraft carriers)," tems, wallcovering, and upholstery. Its Kevlar, with elasticity as high as ny- says Blackledge. "Some spider silks lon. No manmade fiber has those com- also supercontract (that is, the fibers bined properties." get shorter and tighter when wet). This "Spider silk is a hot field right now is unique, and means that spider silk because spiders have evolved a toolkit could be used to make high perfor- of as many as seven types of silks that mance sports clothing that fits better as they use to construct webs. Some of athletes sweat more, or emergency the types of silks in this 'toolkit' are bandages that contract as victims bleed relatively stiff fibers with high tensile more, like an automatic tourniquet." strength, approaching that of our best manmade fibers. Others are highly Potential ' elastic and stretch almost as much as According to Lewis, medical applica- rubber. Many of these silks absorb tions could include artificial ligaments kinetic energy better than almost any and tendons. Michael Ellison at known natural or artificial fibers, Clemson University suggests that it which is what really distinguishes might serve well as scaffolding for spider silk," says Blackledge. cell growth for tissue cultures, or for Both medical and military applica- vascular grafts. Other applications are tions suggest themselves with these also possible—such as automobile material properties.