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Kevlar Diversifies

New applications, licensing agreement fuel growth of advanced fiber.

Jim Phillips

The Wall of Fame is an institution at many companies. Along this few feet of space, be it in a boardroom, lobby or other usually opulent environment, homage is paid to those people who have made significant contributions or enrichments to the history and development of the company.At DuPonts Spruance Plant in Richmond, Va., such a wall exists but one of a different sort. There are no expensively commissioned portraits of company founders, no pictures of past presidents and no tributes to corporate benefactors. There are no expensive frames, and no strategically arranged spotlights. In fact, the display is in an area that is normally not available for public access. Simple frames hang on a plain, painted wall that surrounds one of the plants testing laboratories. In these frames are pictures, plaques and news clippings of men and women who owe their lives to one of Spruances flagship products: DuPonts Kevlar®. A Household NameKevlar is an aramid fiber originally developed in the 1960s by DuPont chemists for use in automobile tires. The advent of the steel-belted radial limited Kevlars presence in that market segment, so DuPont scientists turned their attention to other potential applications, in particular protective clothing. It was in this niche that Kevlar has become virtually a household name, synonymous with bullet-proof vests, SWAT and emergency response teams and other high-risk law-enforcement activities.Inside the test lab around which the aforementioned photos are placed, DuPont conducts ballistics tests to determine the capabilities of certain Kevlar weaves and constructions to absorb, contain and deflect energies from the high-velocity impact of bullets and projectiles. Products with different weaves or fiber construction are given grades that correspond with the force it takes to penetrate the fabric. Depending upon the risk inherent in their assignments, law enforcement officers can choose among Kevlar vests that stop small-caliber bullets to those that will stop .44-magnum and larger shells. 

The record of Kevlar protective garments in protecting those for whom they were designed is impressive. Not once has a Kevlar protective garment failed to perform the task for which it was designed, said Brian E. Foy, senior marketing specialist, Kevlar brand management. There have been a number of instances, however, in which a Kevlar product has protected law enforcement officers from threats for which it was not intended.Foy cited in particular a case a few years ago involving a Virginia State Trooper. The officer made what he thought was a routine traffic stop on a Virginia interstate. However, the cars driver shoved the officer into the traffic lanes, directly into the path of an 18-wheel semi traveling at 65 mph. The trooper caught the impact of the truck full in the chest and was knocked 100 feet down the highway. He was knocked unconscious and should have died immediately from massive chest trauma. But, the Kevlar vest deflected much of the impact force, and the lucky officer walked away with nothing more serious than severe bruises.Strangely enough, though at least to the non-scientific mind a Kevlar vest that will stop a 9-millimeter slug fired from 10 feet way will yield to the puncture of an ice pick thrust with only moderate arm strength. So, for those instances in which law enforcement or military personnel are faced with a greater danger of stabbing than shooting, DuPont manufactures a different Kevlar product that can be woven into a puncture-resistant garment. This particular weave and multi-layer composition of Kevlar can withstand the impact of an ice pick dropped from a height of 10 feet with four pounds of weight, substantially more force than can be provided by a human being.With the success DuPont has enjoyed with Kevlar in life-critical applications, its not surprising the company has now diversified its product offering into a variety of industrial, scientific and popular consumer market segments. As well, because of Kevlars reputation for strength, durability and abrasion resistance, DuPont is finding some companies overemphasize the content of Kevlar within their products, using the name to generate sales without actually providing all of the benefits of Kevlar construction.Before exploring specific new applications for Kevlar, as well as the new licensing program developed by DuPont, it is of benefit to look in more detail at the composition of Kevlar, as well as its fiber forms and potential application areas. The ProductKevlar was developed in 1965 by two DuPont research scientists Stephanie Kwolek and Herbert Blades - who were looking to create a fiber with exceptional strength, but which was also lightweight and flexible. It is an organic fiber in the aromatic polyamide family, also known as aramid. Fibers of Kevlar consist of long molecular chains produced from poly-paraphenylene terephthalamide. The chains are highly oriented with strong interchain bonding that results in an unusual combination of properties. General features include high tensile strength at low weight, high modulus (structural rigidity), high chemical resistance, high toughness, high cut resistance, low elongation to break, low electrical conductivity, low thermal shrinkage, excellent dimensional stability and self-extinguishing flame resistance. 
The product is available in multiple forms, including:Continuous filament yarn: This form features high tensile strength and can be processed on conventional weaving machines, twisters, cord-forming, stranding and serving equipment.Staple: Kevlar staple fiber features very high cut resistance and can be spun using conventional cotton or worsted spinning equipment. Staple consists of precision-cut short fibers, 1/4-inch or longer, and can be processed on felting and spun-lace equipment.Wet pulp and dry floc: These consist of precision-cut short fibers, 1/4-inch or shorter and feature thermal resistance and excellent friction and wear resistance. Pulp and floc are miscible in blend composites.Cord: Kevlar cord features high tensile strength and modulus at low specific weight. It retains physical properties at high and low temperature extremes, features very low heat shrinkage and creep, and has good fatigue resistance.Fabric and prepreg: These forms of Kevlar give good ballistic performance at low weights, excellent friction and wear performance and excellent resistance to cuts and protrusion. 
All Kevlar polymer is mixed and manufactured at Spruance. The fiber is spun at Spruance, as well as two other DuPont locations. In addition to Kevlar, the Spruance Plant manufactures a number of DuPonts other high-performance fiber lines, including Nomex® and Teflon®. Because of the proprietary nature of Kevlar, DuPont prevents access to specific manufacturing processes. However, the strength of the fiber, as well as the way it is produced, requires several innovative processes. Kevlar polymer is mixed and stored in large hoppers. One hopper feeds the two spinning plants at Spruance, while another stores the dry polymer for shipment to another DuPont spinning facility. The fiber is spun and wound in a continuous process. Sulfuric acid is critical to the formulation and production of Kevlar, so the yarn has to be washed repeatedly before it is wound. Special finishes can be added during winding, depending upon the fabrication method anticipated for the yarn. Because of the strength and modulus of the fiber, special cutters are required during doffing to prevent damage. The finished yarn is wound onto packages for weaving, knitting and nonwoven fabric formation. If necessary, additional twist can be added at this stage. Kevlar ApplicationsA comprehensive list of Kevlar applications includes:Adhesives and sealants Thixotropes;Ballistics and defense Anti-mine boots, cut-resistant gloves, composite helmets, and bullet- and fragmentation-resistant vests;Belts and hoses Automotive heating/cooling systems, industrial hoses, and automotive and industrial synchronous and power transmission belts;Composites Aircraft structural body parts and cabin panels, boats, and sporting goods;Fiber optic and electromechanical cables Communications and data transfer cables; ignition wires; and submarine, aerostat and robotic tethers;Friction products and gaskets Asbestos replacement, automotive and industrial gaskets for high-pressure/high-temperature environments; brake pads; and clutch linings;Protective apparel Boots; chain-saw chaps; cut-resistant industrial gloves; helmets (both for firefighters and consumer bicyclists); and thermal- and cut-protective aprons, sleeves, etc.;Tires Aircraft, automobiles, off-road, race vehicles and trucks; andRopes and cables Antennae guy wires, fishing line, industrial and marine utility ropes, lifting slings, mooring and emergency tow lines, netting and webbing, and pull tapes.Kevlar brand fiber is five times stronger than steel on an equal weight basis, Foy said, yet, at the same time, is lightweight, flexible and comfortable. It provides reliable performance and solid strength. Because it is so lightweight, Kevlar enhances freedom of movement even in the most extreme conditions.Kevlar draws its strength from its long molecular structure. When a bullet hits Kevlar fabric, the fabric actually absorbs the energy of the bullet along the molecules of each fiber, catching it in a multi-layered web of woven fabrics. These engaged fibers absorb and disperse the energy of the impact to other fibers in the weave.In addition to the bulletproof and puncture-resistant forms, DuPont also markets what the company calls Multiple Threat Technology, which includes Kevlar encompassed within concealable body soft body armor worn by special law enforcement, security, transportation and correctional officers. It provides cut protection from commercial knives, puncture and slash resistance from hand-made weapons and ice picks, and protection from handguns.The chemical structure of Kevlar also gives it properties useful in industrial applications, Foy said. Gloves, sleeves and aprons benefit from Kevlars high strength, high modulus, thermal stability and resistance to many solvents and chemicals, he said. Kevlar offers strength under heat, protecting against thermal hazards up to 800ºF, and its flexibility enables easy movement.Protective apparel incorporating Kevlar is used in such industries as automotive, steel, glass, metal and forestry, he said. In addition to apparel such as protective gloves, specialized applications have been developed for specific industries. For example, Kevlar is used in chainsaw chaps that provide cut protection for the logging industry and U.S. Forestry Service.Other applications include protection for fiber optic cables, ropes and high-strength composites for aviation and aerospace applications. Hot MarketsLaw enforcement and industrial applications aside, perhaps nowhere does Kevlar have more marketing potential than in sports, recreational and other outdoor activities, Foy said.In competitive sports, the best gear has the tendency to bring out the best performance in the athlete, he said. The major advantage Kevlar brings to performance-oriented activities is an adjustment in attitude. It enables the athlete to focus on performance rather than the product. For example, a cyclist can channel all of his or her energies into winning a race, rather than worrying about the vulnerability to flats of tires reinforced with Kevlar.On the track, where strength and lightness is critical, running shoes with Kevlar soles maximize the energy output of runners while protecting vulnerable parts of the foot. For demanding outdoor recreational activities like hiking or mountain climbing, shoes that incor-porate Kevlar technology provide support and strength and help disperse shock, increase energy and lessen fatigue.Abrasion-resistant jackets, helmets, backpacks and other such products are gaining wide accept-ance among motor-cylists, skaters, hikers and others. In water sports, boats reinforced with Kevlar are lighter and more damage-tolerant, resulting in both hulls and rigs that can withstand extreme weather conditions with improved toughness and durability, he said. Kayaks and canoes are more resistant to damage caused by rocks and submerged tree limbs. For sailing applications, Kevlar adds high strength and low stretch to sails, which can help increase speed.Kevlar is a successful brand for DuPont, according to James B. Ranson Jr., global Kevlar brand manager for Dupont Advanced Fiber Systems. Aided recall studies indicate the brand is in the top 10 percent in brand-name overall impression among consumers and industrial market segments. Consumers, as well, recognize the name and associate Kevlar with high performance, durability and quality, he said. Our goal is to further increase the brand recognition of Kevlar, Ranson said. This becomes particularly important as Kevlar becomes a major player in segments outside the products core markets.It is the experience of DuPont that a strong brand facilitates brand and product extension, particularly with a product such as Kevlar, Ranson said. He described Kevlar as a transformational product. It is not what Kevlar does that is the selling point, but what it allows other products to do. Because of the extensive name recognition of the brand, it is not surprising that many products in high-performance arenas particularly sporting goods leverage the Kevlar name to enhance sales, even if those same products do not necessarily use Kevlar to increase performance.Foy and Gary M. Burnett, senior marketing communications specialist, discussed the case of one athletic equipment manufacturer that mentioned Kevlar six times on the packaging. All well and good, except for the fact that the product contained a very small amount of Kevlar and not in a fashion that enhanced performance.This is an example of the Kevlar name being used to increase sales of a product without providing the consumer any benefit, Foy said. But the fact is, Kevlar could be used to significantly enhance the performance of this product. It is very important to us that when the Kevlar name is on the packaging, the product delivers enhanced benefits for the consumer. Foy said DuPont is working with the manufacturer of the athletic equipment to reformulate the composition of the product to include Kevlar for added strength. New Licensing ProgramAs a result of such experiences, and in a move to protect both its brand integrity and the consumer, DuPont has initiated a new licensing program for Kevlar-enhanced products. The Kevlar Power of Performance licensing program will benefit both serious and recreational athletes in the consumer market and is in keeping with DuPonts corporate strategy of providing market-focused support for its strong portfolio of technical brands, Burnett said.The new program is the result of a three-year research program to understand and define the values, as well as both market and consumer perceptions, associated with Kevlar. DuPont worked with a number of brand and marketing communications experts to develop a new signature for the product, which will debut in 2001 collections.The Power of Performance program requires consumer product manufacturers to secure a royalty-bearing license from DuPont in order to use the Kevlar brand name. This license will be granted only after products made with Kevlar fiber have been shown to comply with stringent quality, performance and compatibility standards, Burnett said. Royalties to DuPont, which will depend upon the end-use of the application, will be calculated as a percentage of wholesale price.Manufacturers that do not qualify for a license can use the Kevlar material, but they will not be allowed to use the Kevlar name.The need to develop the Power of Performance licensing program became apparent to DuPont when it realized the Kevlar brand and its powerful associations to quality and performance was being used fraudulently in the marketplace, Burnett said. A recent survey of some 40 different motorcycle gloves sold in the United Kingdom, for example, revealed an alarmingly high number of them labeled as Kevlar or containing Kevlar when, in fact, they contained either no Kevlar whatsoever or mere token amounts with zero protective capability.With a name and reputation such as that of Kevlar, if the package says Kevlar, the product has to perform. Editors Note: This is the first article in a three-part series that examines the manufacture and marketing of synthetic fiber. ATI chose DuPonts Kevlar® for this series because of the reputation and performance of the product, expansion of Kevlar-enhanced products into new consumer market segments and an aggressive new licensing program undertaken by DuPont to protect the integrity of its advanced fiber brands. In this issue, ATI provides a general overview of Kevlar. In upcoming issues, ATI will profile a plant that weaves Kevlar and provide a look at brand-house and retail marketing of advanced fiber products.

December 2000