反压注射成型对厚壁制品的尺寸稳定性分析  

Analysis of Counter Pressure Injection Molding on Dimensional Stability of Thick-walled Products

作　　者：曹磊 迟文凯 谭伟华[1] 谢鹏程[1] CAO Lei;CHI Wenkai;TAN Weihua;XIE Pengcheng(College of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,China)

机构地区：[1]北京化工大学机电工程学院,北京100029

出　　处：《中国塑料》2019年第4期43-47,共5页China Plastics

摘　　要：为了研究反压压力对厚壁塑料制品尺寸稳定性的影响,利用自行开发的注射反压成型厚壁塑料制品的方案进行了实验,观察分析了反压压力对厚壁塑料制品收缩率的影响。提出一种反压注射成型方式,即在模具型腔内加入活塞,活塞后连接压力元件为其提供反压,依靠熔体的注射压力推动活塞运动,在模具型腔内进行熔体稳流和实时保压,从而减少厚壁塑料制品内应力,得到收缩率较小的理想制品。结果表明,使用丙烯腈-苯乙烯共聚物(AS)为厚壁塑料制品的原材料进行反压注射成型,能够有效减少厚壁塑料制品收缩率,提升其尺寸稳定性,得到较好尺寸稳定性的厚壁塑料制品,同时能够明显缩短保压时长,提高生产效率。To clarify the effect of counter-pressure on the dimensional stability of thick-walled plastic products, a series of experiments were performed for injection-molded thick-walled plastic products by using self-developed solutions. The influence of backpressure on the shrinkage of thick-walled plastic products was also observed and analyzed. Furthermore, a counter-pressure injection molding method is proposed. In this injection mold, a piston was incorporated into the cavity of the mold, and the pressure element was connected to the pressure element to provide backpressure. The injection pressure of the melt was used to push the piston to move, thus stabilizing the melt in the mold cavity. The pressure was maintained in real time, thereby reducing the internal stress of thick-walled plastic products and obtaining an ideal product with a small shrinkage rate. The experimental results indicated that the use of acrylonitrile-styrene copolymer as a raw material for counter-pressure injection molding of thick-walled plastic products could effectively reduce the shrinkage of thick-walled plastic products, thus achieving a better dimensional stability for thick-walled plastic products. Meanwhile, the holding time for pressure could also be significantly shortened, leading to an improvement in production efficiency.

关 键 词：反压注射 厚壁 活塞 压力元件 尺寸稳定性 

分 类 号：TQ320.662[化学工程—合成树脂塑料工业]