The Effects of the Filler Concentration and Preforming Pressure on the Physical Properties for the Composite Material of PTFE-Polyaramid Fiber

Abstract

A fundamental experiment on the development of polymer-based composite materials having a low friction coefficient and wear-resistance has been carried out. Chopped fiber of polyaramid (aromatic polyamide: Kevlar) was employed as the filler and mixed with fine powder of poly-tetra-fluoro-ethylene (PTFE) using a high-speed mixer. The critical pressure P_c, defined as the value at the point of unchanged bulk density, before and after the sintering process, was introduced as an index for the optimal preforming pressure. The relationship between P_c and the concentration of the fiber was expressed as a simple experimental equation. It was shown that the testpiece with a riber content of 14.9vol% preformed at the critical pressure P_c indicated a high modulus of elasticity, fracture energy and strong wearing resistance.