PEEK注塑件成型工艺探讨

Discussion on PEEK Injection Molding Process

以聚醚醚酮(PEEK)带嵌件活门注塑件为研究对象,针对制件成型中出现的缺陷,包括冷料、银纹、气孔、熔接痕及翘曲等,有针对性地提出解决方案;探讨了模具温度、注射成型压力、注射成型温度对制件力学性能及外观的影响。结果表明,对于带嵌件活门制件,为避免银纹产生,对材料150~160℃烘干处理6~8 h基本可以满足加工需求;放慢熔体注射速度对克服制品内部气泡有益,而对于浇口去除后的气孔可以通过延长保压时间的方法来消除;为避免出现熔接痕,可采用嵌件背面中心进料的方式设计模具;消除应力可通过150℃热处理3~4 h;当机筒温度为360~400℃,模具温度控制在175℃左右,注射压力为9.5 MPa,保压压力为7.5 MPa,背压为0.5~1.5 MPa时,成型工艺顺畅,制品表面光滑,有光泽。

Taking polyether ether ketone(PEEK)injection valve with embedded parts as the research object,the targeted solutions were proposed for the defects in the molding of the parts,including the cold material,silver grain,stoma,weld mark and warping;the effects of mould temperature,injection molding pressure and temperature on mechanical properties and appearance of parts were discussed.The results show that for valve parts with embedded parts,the drying treatment at 150–160℃for 6–8 h can basically meet the processing requirements to avoid the occurrence of silver grain.It is beneficial to slow down the melt injection rate to overcome the bubble inside the product,and the stoma after the gate removal can be eliminated by extending the holding time.In order to avoid weld mark,the mould can be designed by feeding in the center at the back of the insert.The stress can be relieved by 150℃heat treatment for 3–4 h.When the barrel temperature is 360–400℃,the mold temperature is controlled around 175℃,the injection pressure is 9.5 MPa,the holding pressure is 7.5 MPa,and the back pressure is 0.5–1.5 MPa,the molding process is successful,and the product surface is smooth and shiny.