In-line plasma source for introducing pieces of spread carbon fiber tow into molding compositions on a compounding production line
View Patent ↗An automated process is provided for debundling carbon fiber tow that includes feeding a carbon fiber tow into a chopper. The carbon fiber tow is cut to form lengths of chopped tow portions. The lengths of chopped tow portions are distributed on a moving conveyor. The lengths of chopped tow portions are exposed to a first plasma discharge from a first plasma source on the moving conveyor to create debundled carbon fibers. Alternatively, the carbon fiber tow is exposed to the first plasma discharge prior to being cut into lengths. A system for applying chopped fibers to a sheet of molding compound includes a chopper for cutting a carbon fiber tow into lengths of chopped tow portions. A conveyor belt receives the lengths of chopped tow portions. At least one plasma generating source is arrayed across of the conveyor.
1. An automated process for debundling carbon fiber tow comprising:
feeding a carbon fiber tow into a chopper;
cutting the carbon fiber tow to form lengths of chopped tow portions, each of the lengths of chopped tow portions having a tow volume;
distributing the lengths of chopped tow portions on a moving conveyor; and
exposing the lengths of chopped tow portions to a first plasma discharge from a first plasma source on said moving conveyor to create debundled carbon fibers.
2. The process of claim 1 wherein the plasma discharge is generated in air.
3. The process of claim 2 wherein the plasma discharge is at atmospheric pressure.
4. The process of claim 1 further comprising placing a sheet of molding compound on said moving conveyor.
5. The process of claim 1 wherein said plasma source is formed as a race track positioned across said moving conveyor.
6. The process of claim 1 wherein the debundled carbon fibers having a debundled volume that is more than 50% greater than the tow volume.
7. The process of claim 1 further comprising exposing the carbon fiber tow to a second plasma discharge prior to said cutting of the carbon fiber tow.
8. The process of claim 1 further comprising forming a rapid thermal molding preform from the debundled carbon fibers.
9. A system for applying chopped fibers to a sheet of molding compound comprising:
a chopper for cutting a carbon fiber tow into lengths of chopped tow portions;
a conveyor belt receiving the lengths of chopped tow portions; and
at least one plasma generating source arrayed across of said conveyor.
10. The system of claim 9 wherein said at least one plasma generating source is a single plasma generating source having a race track annulus emitting plasma into contact with the lengths of chopped tow portions.
11. The system of claim 9 wherein said conveyor belt has a width that ranges between 0.9 to 1.8 meters.
12. An automated process for debundling carbon fiber tow comprising:
exposing a carbon fiber tow to a plasma discharge to form an expanded tow;
feeding the expanded tow into a chopper;
cutting the expanded tow to form lengths of chopped tow portions, each of the lengths of chopped tow portions having a tow volume;
distributing the lengths of chopped tow portions on a moving conveyor; and
exposing the expanded tow to a second plasma discharge prior to said cutting of the carbon fiber tow.