BOEING PROPELS COMPOSITES RECYCLING
In homes and offices throughout the world, recycling bins are ubiquitous. The concept of recycling has become so deeply engrained in society that no matter what you need to discard, chances are you can recycle it. That is, unless you’re looking to recycle glass or carbon fiber composites.
“Everybody knows you recycle aluminum cans, right? You don't even think about it,” says Ed Pilpel, senior advisor at PolyOne Advanced Composites and chairman of the American Composites Manufacturers Association’s Green Composites Council (GCC) Recycling Committee. “There's a bin for it. There's a bin for paper and [other] kinds of recycling. If we ever get to the point where there's a recycling bin for composites, then we know we have achieved success.”
The industry isn’t quite there yet, but according to Pilpel and others, there has been significant progress over the past few years. Recycled CFRP has made major strides recently, and while GFRP recycling has some catching up to do, Pilpel is optimistic. That’s because in all corners of the world, businesses are developing and investing in novel recycling technology and establishing the business case for both carbon fiber and glass fiber composite recycling. All are working toward answering the million-dollar question: How can we make recycling composites profitable?
The Composites and Advanced Materials Expo, CAMX, set for Sept. 23-26 in Anaheim, California, will be addressing many topics and the growing possibilities in composites recycling.
Aerospace titan Boeing, for instance, recently sealed a five-year deal with the United Kingdom’s ELG Carbon Fibre, a commercial recycler, to repurpose leftover composite materials that other manufacturers then will use in products like car parts and computer cases. The materials come from 11 Boeing composite manufacturing sites in the United States and Australia; initially, Boeing will divert about 1 million pounds of material each year.
Boeing uses strong, lightweight carbon-fiber reinforced material to build commercial jets such as the 787 Dreamliner and the 777X.
“Recycling cured carbon fiber was not possible just a few years ago,” says Tia Benson Tolle, Boeing’s materials and fabrication director for product strategy and future airplane development.
Not long ago, the recycling of composite materials was an aspiration, not a reality. Today, though, composites manufacturers and suppliers have come up with various ways to ramp up composites recycling in the United States. One avenue for spreading the ongoing work of the Global Composites Recycling Coalition, which consists of business stakeholders, leading global composites manufacturers ,and companies from Europe, Asia, and the Americas.
Pilpel says the composites industry can gain inspiration from rubber companies that separate the two main components of tires: the nylon core and steel cords. In FRP, the two main components that can be separated are fiber and the polymer matrix.
Recycled parts will be a highlight of CAMX 2019. An exhibit floor display will show what types of things can be made of recycled composite parts, as well as why these parts are important.
Alasdair Gledhill, commercial director at ELG, says commercialization of recycled carbon fiber products is a challenge — a challenge the Boeing-ELG effort tackles.“We are at a point where ELG is in a position to put together a tailor-engineered, specification-grade raw material for use in many different markets,” Gledhill says.
Frazer Barnes, managing director of ELG, explains that 35 percent of the materials his company recycles come from dry waste forms, another 35 percent is laminate material and 30 percent is uncured prepreg. The process can be used to make non-woven mats, milled fibers or carbon fiber reinforced thermoplastic (CFRT) pellets for injection molding or chopped fibers, he says.
ELG’s furnace has a low oxygen content, so the company pyrolyzes the non-carbon fiber materials and turns them into gas, Barnes says. Those gases are burned off in an exhaust treatment system. Later, a carbon char forms on the carbon fiber, and ELG introduces air into the process that oxidizes the char into CO2 and results in clean carbon fiber.
Underscoring the growing importance of carbon fiber recycling, Japanese manufacturing conglomerate Mitsubishi Corp. recently purchased a 25 percent stake in ELG.
Mitsubishi says that by taking a 25 percent position in ELG, it’s “contributing to expanding the stable supply of reprocessed carbon fiber while at the same time continuing to contribute to the sustainable development of industry and the realization of a low-carbon society.”
By stepping up their commitment to carbon fiber recycling, manufacturing giants like Boeing and Mitsubishi are helping overcome a significant roadblock — convincing manufacturers of the urgency surrounding carbon fiber recycling. Ultimately, industry leaders hope all CFRP waste will wind up in the supply chain rather than in scrap heaps.
In the end, the composites industry will be more likely to embrace recycling if there’s a solid business case for it.