As the use of composite materials continues to grow in many different markets, so does the industry’s search for better ways to recycle its products and reclaim the valuable materials that are locked inside them.
Consumer demand is one driver of these recycling efforts. People want to deal with companies that have shown a commitment to sustainable operations. “I think the social pressure is increasing to drive behavioral changes in the industry,” says Andrew Maxey, CEO of Vartega. “The consumer is coming to expect it. We are incentivized through public perception to make some changes here.”
There are also sound economic reasons for supporting recycling. Companies can save money by incorporating reclaimed materials into their applications and releasing the production energy stored within them. “The reality is if we’re going to put a lot of energy into producing materials in the first place, there’s no reason not to reclaim or recover the energy the best we can,” says Maxey.
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Colorado-based Vartega has developed a patented process that recovers the carbon fiber from high-grade, pre-impregnated scrap. The thermoset material that is being recycled – uncured prepreg and dry fiber fabrics – comes primarily from the aerospace industry, which has a scrap rate of about 30%.
The typical prepreg contains about 65% carbon fiber, and Vartega is able to recover it all. Its low-temperature dissolution process employs several different process chemistries to wash away the resins in the scraps and remove the original sizing or chemical binder on the carbon fibers. Almost all of the chemicals used in the dissolution process can be recovered and reused again.
The reclaimed carbon fiber has the same properties as the virgin fiber. “Because we are not degrading or damaging the fiber surface at all, we maintain the mechanical properties, including the strength and stiffness of the carbon fiber,” Maxey says. The fiber has high electrical conductivity and minimal thermal expansion as well.
The stringy, recycled carbon fiber that comes out of the process is chopped and consolidated with a compatible binder for thermoplastic compounding. Vartega is concentrating primarily on the thermoplastic market at present, but has produced carbon fiber for non-woven thermosets as well.
Vartega sells its recycled carbon fiber products at about half the cost of those made with virgin material. Right now, the biggest demand is for polypropylene and polyamide carbon fiber reinforced thermoplastics, according to Maxey. Customers that use this reclaimed carbon fiber include consumer product companies, sporting goods manufacturers and the automotive industry.