Boeing, a major player in the high-end composite
business, is working on applications and processes to produce a recovered carbon
fiber that can be economically re-used in automotive and other applications.
"We have studied and had built tooling that can be
utilized in prototype production and proof-of-concept applications," says Tom
Koehler, communications manager for Boeing Research & Technology. "Boeing
has fielded inquiries from a variety of industries including aircraft parts,
filtration, seating and automotive."
Ability to re-use carbon fiber scrap is a major issue
because carbon fiber is expensive and Boeing will be buying tremendous amounts
of the material for its carbon composite aircraft, the 787 Dreamliner. Boeing
is buying carbon fiber at a cost of $5-$50/lb. At least two-thirds of the fiber
ends up as scrap. Pyrolysis is used to extract fibers from epoxy matrices.
Potentially less expensive sources of carbon fiber are
also important to the automotive industry, which needs to reduce weight of
cars, but has largely shunned carbon composites because of their expense. Work at Boeing is too preliminary to establish potential
costs of the recycled material, which Boeing is designating rCF. Boeing
engineers, however, have determined that the properties of the recycled carbon
fiber hold up for second-use applications.
"rCF study results, to date, indicate that the
replacement of virgin carbon fiber with recycled carbon fiber does not
significantly diminish the physical properties of the materials," says Kohler.
"This is very preliminary work that (we hope) will ultimately enable the
diverse use of recycled carbon fiber in high-grade manufacturing applications
(such as some aerospace applications) and help quench the arguments surrounding
the diminution of fiber properties with recycling."
Boeing currently does not use any recycled carbon fiber
products in its manufacturing.
An increasing number of decommissioned aircraft, which
contain smaller amounts of carbon composites than the Dreamliner, may also
become an important source of scrap material. Some estimates place the number
of aircraft that will be retired over the next 20 years at close to 6,000.