Attendees of the Automotive Light Weight Material Summit in Detroit this past summer were treated to a revolutionary product created from recycled carbon fiber material. The carbon fiber seat back they saw is the result of some exceptional work done by the Composite Recycling Technology Center in partnership with the UK’s ELG Carbon Fibre Ltd.
A car seat back made of recycled carbon fiber material may not seem like such a big deal to the average car owner who doesn’t understand how composite materials are manufactured. But it is a tremendous breakthrough for companies and individuals involved in the composite materials industry. It signifies yet another milestone in the pursuit of new construction materials that are more sustainable and environmentally friendly.
What They Built
The Composite Recycling Technology Center and ELG worked with a Tennessee organization, the Institute for Advanced Composites Manufacturing Innovation, to create a process whereby carbon fiber material could be recycled, retooled, and made into new products. For their initial project, they came up with a bucket-style automotive seat back.
The seat back measures 24″ x 19″ and includes side flanges as deep as 5 inches. The composite material that makes up the seat back was created with recycled fiber/nylon 6 resin using a 300-ton hot-platen press. That material was then molded into the finished product using an aluminum molding tool that was developed as a prototype for evaluation purposes.
Obviously, representatives from all three partners have been quick to state how excited their respective organizations are about the success of the project. Now their attentions will turn to developing a way to automate scrap composite material processing and remanufacturing. Once automation can be achieved, repurposing carbon composite materials on a large scale can begin in earnest.
Not an Easy Task
At Rock West Composites outside of Salt Lake City, Utah, they make an extensive list of composite material products ranging from carbon fiber fabric plates to shaped tubing. Company officials are aware of just how hard it is to recycle composites in a cost-effective way. It is not as simple as recycling something like aluminum, something that can just be melted down and recast into new parts.
The difficulty with composite materials is the fact that they are created by combining a number of individual materials that have significantly different physical and/or chemical properties. Rock West’s carbon tubing, for example, starts with carbon fibers that can be as small as 10 micrometers in diameter. These fibers are made primarily of carbon atoms bonded together to form long strings of crystals that can be woven into a fabric.
Carbon fiber fabric can then be combined with other materials to create a composite that can be molded into whatever designers want to create. All of that is well and good. The problem engineers face is one of reversing the process so that composite materials can be repurposed without damaging the integrity of the composites themselves.
Heat is the most common means of molding composite materials into the desired shape. But once molded and cooled, most carbon fiber composites actually reflect heat, making it more difficult to use heat in the recycling process. As a result, recycling carbon composites cost-effectively will require a new way of doing things.
The three partners that created the recycled seat back have accomplished something major in the world of composite materials. They have proven it can be done, which is the first step in reclaiming composite materials to be repurposed. Now it is only a matter of time before they develop a system for automated composite recycling and remanufacturing.