Patent ID: 7632436
Filing Date: 2009-12-15
Classification: B29K,B29L,C04B,F16D

Abstract:
1. A process of manufacturing a carbon-carbon composite preform, which process comprises the steps of: (i.) arranging a batch of carbon fiber preforms in an infiltration vessel; (ii.) flooding the vessel with hot liquid phase pitch at atmospheric pressure in an inert atmosphere by providing a continuously heated holding tank for the pitch, maintaining a continuous supply of heated pitch therein, and continuously supplying heated pitch to the infiltration vessel, wherein the pitch is circulated from the infiltration vessel to a melt tank where additional heat is imparted to the pitch and the pitch is then circulated back into the infiltration vessel in order to speed heating of the preforms; (iii.) raising the pressure in the infiltration vessel from atmospheric pressure to an elevated pressure of at least 100 psi, and then lowering the pressure at a rate of 20 psi per minute or less; (iv.) repeating step (iii.) from 3 to 7 times.