B12 模具温差控制对液体辅助射出成型圆管件偏心率影响之探讨

模具温差控制对液体辅助射出成型圆管件偏心率影响之探讨

Effects of Mold Temperature Gradient on the Thickness Distribution of Water-Assisted Injection Molded Parts

张富安 黄俊杰 刘士荣*

长庚大学 机械工程研究所

Institute of Mechanical Engineering,Chang Gung University

中文摘要

本研究利用液体辅助射出成型，探讨两种不同熔融流动指数之聚丙烯，其圆管件弯曲处偏心情形，并与气辅射出件进行比较。参数设定方面，主要是以圆管件内外侧的模具温差做变化，观察其对偏心率的影响，并与其他参数(如:射胶温度、液体压力等)做比较。最后应用模流分析软件，以内外侧不同温差，观察弯管处温度场分布情形，藉由计算机分析及实验结果加以比较。结果发现在液辅制程上，主要影响偏心率的参数为射胶温度，模具温度及液体压力；气辅制程上主要影响偏心率的参数为射胶温度及模具温度。模具温差对于不同融熔流动指数之聚丙烯及气液辅制程上所造成的偏心率结果也有所不同。

英文摘要

The study investigated the effects of molded temperature gradient on the thickness distribution of water assisted injection molded parts. Experiments were carried out on an 80-ton injection-molding machine equipped with a laboratory scale water injection system, which included a water pump, a water injection pin, a water tank equipped with a temperature regulator, and a control circuit. The materials used in this study were two different melt flow rate polypropylene. Various processing variables were studied in terms of their influence on the thickness distribution of molded parts, including melt temperature, mold temperature gradient, water temperature, water pressure, short shot size, water hold and water injection delay time. In addition, the water assisted process was compared with gas assisted process. For single parameter of water assisted process, the major influence the thickness distribution was the melt temperature, mold temperature gradient and water pressure. For single parameter of gas assisted process, the major influence the thickness distribution was the melt temperature and mold temperature gradient .In water assisted process, the result found that the mold temperature gradient in two different melt flow rate polypropylene has give different thickness distribution.

关键词：液体辅助射出成型、偏心率、模具温差、熔融流动指数。

  

    

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