微结构注塑件充填不平衡实验

Unbalanced Filling Experiments of Injection Plastic Parts with Microstructure

针对微尺度充填不平衡现象,采用微细电火花铣削技术设计制造了一模八腔的带有微圆柱孔的注塑模具。以聚丙烯为原料进行单因素充模流动工艺实验,研究了模具温度和注射速率对直径为200μm微圆柱孔充填高度的影响规律。结果表明,当模具温度为30℃和注射速率为60%(注塑机最大注射速率的百分数)时,对称分布的两个型腔中同一位置微圆柱孔充填高度差别较大,最大差值达到了101μm,充填不平衡现象明显。随着模具温度和注射速率的升高,当模具温度为50℃和注射速率为90%时,对称分布的两个型腔中同一位置微圆柱孔充填高度差别变小,最小差值达到了1μm,充填不平衡现象在减弱。

Aiming at the micro scale filing unbalance phenomenon,a eight cavity injection mould with micro-cylinder holes was designed and manufactured by micro EDM milling technology.Polypropylene(PP)was used to carry out single factor filling flow experiments.The effects of mould temperature and injection rate on filling heights of micro-cylinder holes with diameter of 200μm were studied.The results show that the filling heights of micro-cylinder holes at the same position in two symmetrically distributed cavities vary greatly when the mould temperature is 30℃and the injection rate is 60% (percentage of maximum injection rate of injection machine),the maximum height difference reaches 101μm,and the filling imbalance is obvious.With the increase of mould temperature and injection rate,the filling heights of micro-cylinder holes at the same position in two symmetrically distributed cavities have little difference when the mould temperature is 50℃and injection rate is 90%,the minimum difference reaches 1μm,and the filling imbalance is weakening.