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


"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

--- 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

--- 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

--- 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

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

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