计算机模拟的工艺参数及模具结构对双组分注塑PP/TPE结合强度的影响

针对于双组分注塑质量稳定性差的问题,以Ford C346发动机舱侧饰条制备为例,采用注塑级改性聚丙烯(PP)为硬料,热塑性弹性体(TPE)为软料,通过计算机辅助工程进行模流分析,设计生产工艺参数及模具的结构,通过拉伸强度测试验证了双组分注塑工艺参数和模具处理对软硬料结合强度的影响。结果表明,模具温度60℃,熔体温度210℃,注射速度20cm3/s和保压压力7 M Pa是双组分PP/TPE注射的最佳工艺条件;模具结构采用增加硬料和软料接触面的粗糙度、对硬料加固处理和圆弧过渡方式可明显改善PP/TPE结合强度。计算机分流模拟的结果与实践结果基本是相同的。

Effect of the Technological Parameter and Mold Structure of Computer Simulation on the Bonding Strength of Two-component Injection PP/TPE

Aiming at the poor quality stability of two-component injection molding,taking the preparation of side trim strips for the Ford C346 engine room as an example,the injection-grade modified polypropylene(PP) and thermoplastic elastomer(TPE) were used as the hard and the soft materials,respectively.The computer aided engineering was applied to conduct mold flow analysis to design production process parameters and mold structure,the effects of two-component injection molding process parameters and mould treatment on the bonding strength of hard and soft materials were tested by testing tensile strength.The results show when the mold temperature is60℃,the melt temperature is 210℃,the injection speed is 20 cm^3/s and the holding pressure is 7 MPa,the two-component PP/TPE injection could obtain the best processing conditions.The combination strength of PP/TPE could be significantly improved by increasing the roughness of contact surface between hard and soft materials,reinforcing treatment and arcing transition of hard materials.The results of computer shunt simulation are basically the same as those of practice.