Developing Options for Recycling Carbon Fiber Composites
Carbon fiber, also known as graphite fiber, is an incredibly strong material that is also very lightweight -- making it the ideal starting material for manufacturing a variety of parts. While parts made of carbon fiber composites proliferate, finding a way to recycle this resilient material has been challenging. Researchers are finally finding ways to re-use this expensive material by breaking them down with a mix of mild catalysts at relatively low temperatures that still preserves the fibers.
History of Carbon Fibers
Carbon fiber is made of thin, crystalline filaments that grow in strength when they are twisted together, similar to the way string or yarn is created. These strands are then woven into a type of fabric that can be laid over a mold for the addition of plastic or resin for a more permanent structure. The low weight to strength ratio as well as the high tensile strength, extreme chemical resistance, low thermal expansion and high heat tolerance make carbon fiber viable for a range of applications such as automotive, military, aerospace and more. However, the very durability of the substance has made it challenging to recycle -- until recently.
How Recycling Carbon Fibers Works
When scientists attempted to recycle carbon fiber using traditional methods, they discovered that grinding or breaking them down mechanically or at high temperatures was the only way to recover the expensive fibers. The incredibly harsh chemicals required to break down the fibers were dangerous and still destroyed the matrix of resin materials. Recently, researchers at Washington State University (WSU) discovered a much less invasive way to release the carbon fibers into re-usable fragments by using mild acids such as liquid ethanol to make the resins expand, breaking the molecular bonds.
Benefits of Recycling
The expense of manufacturing carbon fiber has caused the recycling efforts to be watched carefully. Researchers at the Georgia Institute of Technology recently discovered yet another way to recycle this exceptional material using an alcohol solvent to dissolve the bonds of the epoxy that shape the fibers. Both the epoxy and the fibers, once separated, are in a form that can be utilized in new applications. While this method only works for carbon fiber composites that use a vitrimer epoxy, this finding along with the work of the researchers at WSU are providing good strides to the efforts to recycle this valuable material.
Want to keep up to date on the latest recycling news that you can use? Follow Central Kentucky Fiber Resources on LinkedIn or check out our blog. Our recycling facility in Central Kentucky can accommodate loads of all sizes -- whether they are loose, baled or anything in between. We are committed to sustaining the environment and preserving natural resources through minimizing waste and preventing pollution.