碗形盖带内螺纹孔塑件多材共用型热流道模设计

Design of Universal Hot Runner Mold for Bowl Cap with Internal Thread Hole based on Multiple Plastics Materials

为降低碗形盖塑料件使用丙烯腈-丁二烯-苯乙烯塑料(ABS)注塑成型的成本,选购了一种性能与ABS相当的改性PP塑料用于塑料件的注塑成型,设计了一副能适应于ABS及改性PP通用的两板热流道注塑模具。模具1模4腔布局,单个模腔使用热嘴供料的3个潜伏式浇口进行浇注。模腔主要成型件材料使用S136合金钢,热处理硬度HRC52~54。模具中,使用了蜗杆传动副用于驱动4个模腔内螺纹型芯的旋转抽芯脱模,脱螺纹机构采用机械式传动机构,动作可靠、制造简单、安装方便,有效地降低了模具的制造成本。顶出机构设计为一种双层顶出机构,较好地解决了塑料件内孔中流道废料难脱模的难题,保证了模腔能使用3个浇口进行浇注,使模具能适用于注塑ABS塑料和改性PP塑料。

In order to cope with the cost pressure of using acrylonitrile butadiene styrene plastic(ABS)plastic for injection molding of bowl-shaped cover plastic parts,a modified polypropylene(PP)plastic with the same performance as ABS was selected for injection molding of plastic parts.Based on this,a two-plate hot-runner injection mold suitable for ABS and modified PP was designed.Mold’s layout was 1 mold with four-cavities and a single mold cavity was gated with three latent gates fed by a hot nozzle.S136 alloy steel with heat treatment hardness of HRC52-54 was used as the main molding material of the mold cavity.In the mold,the worm drive pair is used to drive the rotary core-pulling and demoulding of the threaded cores in the four mold cavities.The demoulding mechanism adopt a mechanical drive mechanism with reliable action,simple manufacturing and convenient installation,effectively reducing the mold manufacturing cost.The ejection mechanism was designed as a double-layer ejection mechanism,which solved the problem of difficult demoulding of runner waste in the inner hole of plastic parts,ensured that the mold cavity can be gated with three gates,and enhances the applicability of the mold for injection of ABS plastic and modified PP plastic.