of the ptfe particles the flexural modulus the frictional coefficient u03bc in oil and the extent of self wear and the extent of counterpart material wear following a sliding test for the obtained sample the peek ptfe and carbon fibers cf used were the aforementioned commercial products in a mass ratio peek ptfe cf of 70 10 20 the flexural modulus the frictional coefficient u03bc in oil and the extent of self wear and the extent of counterpart material wear following the sliding test were expressed as relative values with 100 as the value for comparative example 5 described below measuring samples comparative examples 4 and 5 were fabricated in the same manner as comparative example 1 and comparative example 3 respectively except that carbon fibers cf were supplied from a side feeder instead of peek and ptfe table 2 shows the results of measuring the mean particle size of the ptfe particles the flexural modulus the frictional coefficient u03bc in oil and the extent of self wear and the extent of counterpart material wear following a sliding test for each sample the mass ratio of peek ptfe and cf peek ptfe cf was 70 10 20 the flexural modulus the frictional coefficient u03bc in oil and the extent of self wear and the extent of counterpart material wear following the sliding test were expressed as relative values with 100 as the value for comparative example 5 in example 6 and.