Microcellular injection molding of polyether-ether-ketone

Polyether-ether-ketone (PEEK) has been widely used in aerospace field for its excellent performance. Microcellular injection molding (MIM) is a promising method to reduce product weight and save energy consumption. In this study, microcellular PEEK was prepared by injection molding. Firstly, the thermal properties of raw PEEK, injection molded PEEK, and foamed PEEK were investigated and results show that the thermal performance of the three types of PEEK were similar. Secondly, the effects of process parameters, including melt temperature, injection speed, injection volume and gas concentration, on microcellular PEEK were studied. The results show that injection volume had the most significant influence on the weight-reduction ratio and tensile strength, while the change of melt temperature, injection speed, injection volume and gas concentration could alter the internal cell structure. After optimization, two kinds of microcellular PEEK with the largest weight-reduction ratio of 17.29% and the greatest tensile strength of 74.13 MPa were obtained respectively. Thirdly, the effect of carbon fiber on microcellular PEEK was preliminarily studied. It was found that carbon fiber could promote the formation of dense cell structure. This work laid the foundation for further fabrication of high strength and light weight microcellular PEEK.