Using the plastic chain link which is made of glass fiber reinforced PA6 of desanding machine for sewage treatment in sewage treatment plant as example,the injection moulding process of the link was investigated. The effects of barrel temperature, injection pressure,injection speed,holding pressure and holding time on the weight and appearance of the link were studied by using the orthogonal analysis method and the injection moulding process parameters were optimized. The results show that the barrel temperature is the largest effect on the link weight,the injection pressure is the second effects,the effect of the holding pressure is small,the injection speed and holding time have little effect on the link weight. When the barrel temperature is 250℃,injection pressure is 85 MPa,injection rate is 55 mm/s,holding pressure is 70 MPa and holding time is 9 s,the molded link has maximum weight which’s value is 275.8 g and its appearance is smooth and has no fiber floating phenomenon. When the chain comprised of the links was installed on desanding machine in sewage treatment plant for practical working,it could meet the design requirments of working for four month. The tensile test results show that the tensile fracture strength of the 272.3 g link molded without optimizing the injection moulding is lower than that of the 275.8 g link molded after optimization and the tensile fracture section at the root of the 272.3 g link has obvious hole.%以污水处理厂污水除砂机使用的玻璃纤维增强尼龙6塑料链条的链节为例，对其注射成型加工工艺进行研究。采用正交实验法研究了料筒温度、注塑压力及速度、保压压力及时间等工艺条件对成型链节的外观和质量的影响并对成型工艺参数进行了优化。结果表明，料筒温度对链节质量的影响最大，注塑压力的影响其次，保压压力的影响较小，而注射速度和保压时间对质量几乎没有影响。当料筒温度为250℃，注塑压力为85 MPa、注射速度为55 mm／s，保压压力为70 MPa、保压时间为6 s时，成型链节的质量最大，为275.8 g，其外观光滑，无“浮纤”现象，由其组成的链条在污水处理厂装机实际运行时，达到了设计上要求的4个月的运行时间。拉伸试验结果表明，未优化前成型的272.3 g链节的拉伸断裂力低于优化后成型的275.8 g链节，且272.3 g链节根部拉伸断面有明显缩孔。
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