TO RECOGNIZE SUB-STANDARD CARBON FIBER
we have seen an increase in "carbon fiber" sheets and
other products for sale in stores as well as on the web. Since
the knowledge of composites and it's use is still relatively
minor, we would like to give some information to the consumer
so you may be aware of some of the sub-standard product that
are presented as carbon fiber.
purchased on-line a sheet of flat "carbon fiber" stock.
Below is an inspection and photos of what was received.
While the dimensions were correct at 2.0" x
14.0" x 1/8" thick, the thickness tolerance was 0.041".
While this is acceptable for a sheet of plywood, it is not for
a fabricated composite sheet. We also found that we did not receive
flat stock either, this piece bowed up in the middle by 1/8" and
had a 1/8" opposing corner twist to it. Good thing we were
not going to try and use it for any project.
breakdown of the construction of thie piece is one layer of an
unknown 3K plain weave fabric bonded to approximately two layers
of chop fiberglass mat (chop fiberglass mat is the cheapest composite
material available) with a black fiberglass veil as a backing,
all bonded with polyester resin (polyester resin is the cheapest
lowest grade resin available). The conclusion is that while there
is one carbon fiber layer in the part, it does not have any other
properties associated with it such as high strength and low weight
or have any tight manufacturing tolerances.
The conclusion is that the piece we received was not quite carbon
fiber, just a sub-standard product made to fool consumers thinking
they were purchasing real carbon fiber.