模具温度对高光成型制品收缩影响试验

Influence of Mold Temperature in Rapid Heat Cycle Molding on Shrinkage of Plastic Part

以自主开发的车载蓝牙外壳模具和温控辅助装置为试验基础,对模具温度对高光制品成型收缩影响规律、不同模温条件下其它参数对制品收缩影响规律、及保证相同品质条件下各参数随模温变化规律进行试验研究。结果表明,模具温度对制品收缩影响最主要特点是当模温提升至塑料热变形温度之后制品线收缩率明显减小;在相同模温条件下,压力和温度因素对制品收缩影响显著,而时间因素影响甚微;随着模温的逐步提升,在熔体温度、注射压力一定条件下,制品线收缩率呈小幅减小趋势,而对于保压压力、保压时间或冷却时间则呈"V"字型小幅波动变化。

By integrating the mold for front panel of mobile key and auxiliary device for controlling mold temperature,which was developed independently,the influence law of mold temperature in rapid heat cycle molding on shrinkage of part was investigated. This research also studied on other parameters influencing on shrinkage with fixed or changed mold temperature. The results reveal that the most significant influence of mold temperature on shrinkage is it would be decreased apparently,when it is set on higher than the thermal deformation temperature of polymer. Temperature factors and pressure factors are more important on shrinkage,while time factors have no obvious effects. With increase of mold temperature,part shrinkage would be decreased by a small margin with same melt temperature or injecting pressure,while it would be fluctuated as a ＂V＂ shape within a narrow range with same packing pressure,packing time or cooling time.