An estimated 60 million personal computers enter the market every year. About 12 million are thrown out.
Professors at West Virginia University in Morgantown say they are close to commercializing a process of making wood-plastic composite deck boards using recycled ABS from discarded computers. They are also making glass-filled polycarbonate-based products using predominantly recycled material.
The National Safety Council in Itasca, Ill., predicts that some 680 million computers will be obsolete within the next few years and that the waste from those machines will contain more than 4 billion pounds of plastic, according to London-based Economist Intelligence Unit, a research and analysis firm.
``That's how we got into it,'' said WVU professor of chemical engineering Rakesh Gupta in a Feb. 22 telephone interview. ``The mission of the center is to use composites in construction.''
The U.S. Department of Energy and the Environmental Protection Agency are funding the project. Researchers like Gupta; Hota GangaRao, a WVU professor of civil and environmental engineering; and Ben Dawson-Andoh, an associate professor of wood science with WVU's Division of Forestry, are working to remove recyclable plastics from the waste stream through new product development.
While GangaRao is working on high-volume products like spacer blocks for guardrails and sound barriers, Gupta said he is focused on developing higher-value end-use products.
``My initial work was to examine the influence of impurities on plastics properties,'' Gupta said. ``The mechanical properties - impact strength and ductility - become unacceptable when you have mixed plastics.''
Gupta then turned his focus to finding out what can be mixed with recycled ABS and PC so that product performance is on par with virgin material.
Composite decking was sort of a no-brainer.
Gupta said ABS has better performance characteristics than both polyethylene and polypropylene - the two plastics most commonly used in wood-plastic composite deck, fence and railing systems. Also, its melt point is lower than other engineering thermoplastics, which keeps the obligatory 50 percent wood fiber from burning during processing. Other engineering polymers, Gupta said, require temperatures too high to use the wood fiber mix.
``We're doing exactly what the [composite lumber] industry is doing,'' he said. ``But by using ABS, we're using a new supply stream, and the mechanical properties are better, and the stiffness is higher.''
Dawson-Andoh said he has been studying durability and biological deterioration.
``Maybe we can make a better and stronger product,'' he said. ``Some composite decks have lousy strength properties. To make it structural, you have to improve the interface.''
He is also focusing on a microbial-retardant formula.
``We're looking at cheaper, very simple techniques of providing protection against microbial colonization,'' Dawson-Andoh said. ``Wood is cheap. Use of recycled materials is cheap. So the process of giving protection has to be cheap.''
Joist spacing requirements for composite decks have long been considered a detriment, often requiring twice as much substructure support as their natural wood equivalents. Using ABS composites, deck boards require joist spacing similar to that of traditional deck boards, Gupta said.
``The stiffness is almost twice that of polypropylene,'' he said.
Work with glass-filled PC products made from recycled material also has progressed, he said.
Lab results indicate that at least 15 percent of glass-fiber reinforcement virtually eliminates any performance gap between recycled PC and its virgin counterpart.
``It comes down to value that's exactly the same,'' Gupta said. ``You could have a matrix containing 25-30 percent impurities, and the properties are indistinguishable.''
It is a replacement material, Gupta said. Anything made with glass-filled PC also could use his recycled mix. Impact shields, fluid-handling components, manifolds, electrical components and equipment housings are among the products made of glass-filled PC.
``The only issue is color,'' he said. ``Typically, you can only get gray or black, so you may not want to use it in visible applications.''