Carbon fiber composites

Abstract

Disclosed is a method of producing a carbon fiber felt which includes the steps of preparing a substantially unidirectional array of continuous carbonizable filaments in oxidized state, cross-laying other such filaments on one side of said array in a state of restraint from displacement from their cross-laid relationship, and needle-punching the resulting assembly from the same side. Also disclosed is a method of pre-sizing a high bulk, low density carbon fiber felt comprising the steps of impregnating said felt with a thermoplastic or thermosetting resin highly diluted in a solvent, and removing said solvent either before or while the assembly is being reduced to its final dimensions to leave the resin per se as a coating on the fibrous material serving to adhere individual elements together at cross-over points to prevent displacement thereof, all prior to the addition of the matrix material in which the carbon fiber is embedded to form the final composite. The disclosure also embraces felts made by such methods and incorporated in composites.

Dependencies are inferred from the claim text.