Patent ID: 6955853
Filing Date: 2005-10-18
Classification: B32B,C04B,Y10T

Abstract:
1. A low density organic polymer impregnated preformed fibrous ceramic article comprising a plurality of layers wherein (A) a front layer of the article comprises fibers selected from the group consisting of ceramic fibers, carbon fibers and combinations of ceramic and carbon fibers; said front layer being impregnated with an amount of at least one organic polymer; (B) a middle layer comprising polymer impregnated ceramic fibers; and (C) a back layer comprising fibers selected from the group consisting of ceramic fibers, carbon fibers, and combinations of ceramic and carbon fibers; said back layer of the article comprising fibers impregnated with an amount of at least one low temperature pyrolyzing organic polymer capable of decomposing without depositing residues, wherein said polymer impregnated ceramic fibers in said middle layer include one of the following groups of fibers; (1) 12–15 weight percent Nextel fibers, 20 weight-percent alumina and 63–65 weight-percent silica fibers and having a void fraction in a range of about 95–95 percent; (2) 12–15 weight percent Nextel fibers, 50 weight-percent alumina and 35 weight-percent silica fibers and having a void fraction in a range of about 95–96 percent; (3) about 98.5 percent ultra microquartz and about 1.5 percent silicon carbide, having a density of 0.15–0.17 gm/cm 3 , and having a void fraction in a range of about 92–94 percent; (4) about 98.5 percent ultra microquartz and about 1.5 percent silicon carbide, having a density of 0.12–0.14 gm/cm 3 , and having a void fraction in a range of about 93–95 percent; and (5) all carbon fibers and having a void fraction in a range of 88–93 percent.