Composite

Layerings

Layer One "[C]ompanies produce a class of structural materials called metal matrix composites (MMCs) that blend the technologies of metal alloys with engineered resin-matrix substances such as carbon fiber. Unlike alloys, which combine their elements at a molecular level, MMCs consist of a base metal (aluminum is common) reinforced with bits of higher-strength materials, such as silicon carbide, held in suspension in the metal matrix. The result is a material that can be stronger, stiffer, and lighter than its base metal. "Univega Unveils Boralyn. Prior to January `92 Boraylin (pronounced bore-Al´-in) was a classified defense material used in missile fuselages and the ballistic armor sheeting of Apache helicopters and M-1 tanks. The weldable MMC comprises particulates of titanium and boron carbide (the hardest man-made substance, equal to diamond), suspended in an aluminum base. The resulting material is 40% lighter than titanium, 83% stiffer than steel, and ductile enough to avoid the catastrophic failures possible with aluminum. The material's crystalline structure is also said to diffuse road/trail shock better than straight metal." John Kukoda, Bicycling, Nov. 1993, p. 88.

Layer Two "The Allison Gas Turbine division of General Motors achieved a milestone a year ago by making the first rotating part, a compressor ring, from a titanium alloy embedded with silicon carbide fibers. The thin ring, which holds compressor blades on the engine shaft, weighs 10 pounds and replaces a nearly 60-pound solid disk. Because metal-matrix composites are stronger than the alloy parts, fewer rotors are needed. `You can get a rotor that runs faster and one that is able to achieve higher pressures,' says Ronald E. York, Allison's director for advanced engine projects. "Allison made the ring by interleaving helical coils of titanium with others that contain the woven fibers. The coils are then squeezed together at high temperatures and pressures, a process York compares with fusing Slinkies that are sandwiched together. Designing the coils severely challenged Allison materials and structural engineers: each fiber has to be carefully oriented within the metal matrix to provide the maximum resistance to centrifugal forces generated as the rotor turns." --- Scientific American, December, 1992

Layer Three WORLD'S FIRST RECYCLED SHOE "DEJA Inc.'s line of ECO SNEAKS and ENVIROLITES shoes are high-quality, comfortable, functional, durable footwear designed for casual use. The shoes are made from an eclectic array of pre- and post- consumer recycled rubbish that includes trim waste from diaper factories, coffee filters, paper bags, plastic pop bottles, milk jugs and tire rubber. A closer look at DEJA's new shoes reveals a wide range of recycled materials including: --- Upper/outer fabric and inner lining material in the ECO SNEAKS made from 100 percent recycled cotton canvas from ECO FIBRE, a new high-quality yarn spun from recovered and recycled natural and synthetic fibers. --- Molded upper rubber parts constructed from 60 percent thermal plastic rubber, 30 percent of which is post-consumer recycled material from tire rubber and polystyrene coffee cups, and 30 percent of which is pre-consumer recycled polypropylene from the trim waste during the manufacturing of diapers. --- Developed by TEXON, the lasting board is made from 100 percent recycled fibers manufactured from reject coffee filters and file folders. --- In the ECO SNEAKS, the interfacing material between the outer fabric and the inner lining employs a non-woven polyester material that is 80 percent post-consumer recycled polyester soda pop bottles. --- Foam used in the upper collar area and tongue is 100 percent recycled materials from seat cushions and chairs. --- The heel counter stiffener is made from trim waste from the resin materials used by other shoe makers. DEJA's supplier has agreed to buy back and reprocess trim waste from other shoe manufacturers on behalf of the company. --- The neoprene foam cushioning attached to the lasting board is 100 percent pre-consumer recycled trim waste from wetsuit and gasket manufacturers. --- The shank board, which provides the shoe's stability, is made from 100 percent recycled grocery bags and corrugated cardboard. --- For the outsoles, DEJA is using a new process binding 50 percent pre-consumer recycled rubber, destined for incineration or the landfill, with 50 percent virgin rubber. Research is underway to create a material with an even higher percentage of recycled rubber. --- Midsoles are 40 percent pre-consumer recycled ethyl vinyl acetate foam made from other shoemakers' scrap, which may have otherwise gone to a landfill. --- Laces are 100 percent cotton. --- The unique DEJA shoe box is made from 100 percent recycled corrugated cardboard with water-based inks used in the printing. To encourage customers not to throw it away after purchasing the shoes, the decorative shoe box is ingeniously designed to be used as a gift box. The box is constructed so that it can be easily folded inside out, revealing beautiful etchings of rare and endangered animals. When the shoes eventually wear out, customers can send them back to DEJA to be recycled again. "We'll encourage consumers to recycle their old shoes by sending them back to us. By doing this, we can further control the entire life cycle of our products," explains Lewis. Based in Tigard, Ore., DEJA Inc. is a footwear, apparel and accessories company devoted to developing and applying new recycling technologies to achieve profitability through sustainable development growth that meets current human needs without sacrificing the needs of future generations." source for Layer Three: PR Newswire Association, Inc. August 19, 1992, Wednesday LAS VEGAS, NV

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