Yarn for reinforcing composite materials
A yarn for reinforcing composite material includes carbon nanotubes. The yarn has also been treated to promote interaction with a resinous matrix.
1. A method for manufacturing a composite material, said method comprising forming carbon nanotubes, spinning said carbon nanotubes into a yarn comprising four strands of carbon nanotube fibers, treating said yarn with a pre-treatment of a thermoplastic resin to promote swelling of the yarn, wherein the pre-treatment is with at least one of the thermoplastic resins selected from the group consisting of PEEK, PEI, urethane or polyimide, passing said yarn through a plurality of layers having interstitial spaces filled with a resinous matrix, swelling the yarn and allowing the pre-treatment thermoplastic resin to fuse with the resinous matrix.
2. The method of claim 1 , wherein said yarn is also pre-treated with sizing prior to passing said yarn through the plurality of layers.
3. The method of claim 1 , wherein said yarn is pre-treated with spalling prior to passing said yarn through the plurality of layers.
4. The method of claim 1 , wherein said yarn is pre-treated with a friction-reducing film prior to passing said yarn through the plurality of layers.
5. The method of claim 1 , wherein the thermoplastic is selected from the group consisting of PEEK and PEI.
6. The method of claim 1 , wherein the thermoplastic is a urethane-based plastic.
7. The method of claim 1 , wherein the thermoplastic is a polyimide.
8. The method of claim 1 , wherein forming carbon nanotubes comprises forming said carbon nanotubes at a temperature higher than 1000° C.
9. The method of claim 1 , wherein the yarn is passed through the plurality of layers in a direction normal to a horizontal plane defined by the plurality of layers.
10. The method of claim 1 , wherein the yarn is passed through the plurality of layers at an angle to a horizontal plane defined by the plurality of layers.
11. The method of claim 1 , wherein the pre-treatment resin penetrates all the way through the yarn.
12. The method of claim 1 , wherein the four stands of carbon nanotube fibers form a helical pitch having a helical angle of about 15 degrees.
13. The method of claim 1 , wherein the yarn is further coated with a friction-reducing film.