The Measuring Method In Injection Molding With Ultrasonic waves

介绍了超声波在注塑成型过程中的测量方法。发展了一种监测聚合物熔体流动和冷却行为的方法，测量热塑性塑料模塑的结晶度、腔内注射压力和锁定力的方法，以及检测薄闪光的原因的方法。(1)聚合物熔体的流动行为可以通过反射波振幅的变化来获得。(2)通过塑料在型腔内固液两相的流动时间，可以得到塑料在厚度方向上的冷却行为和温度分布。(3)通过测量纵向声速可以间接获得结晶度。(4)超声波在模具表面与放置在模具表面的金属箔界面处的反射回波比与型腔压力成正比。(5)通过测量分型面处的反射回波比，可以确定锁模力的行为和产生薄飞边的原因。

This paper describes the measuring method in injection molding process by using ultrasonic waves. A method of monitoring the flow and cooling behavior of polymer melt, methods of measuring the crystallinity of the molded plastics of thermoplastic, the injection pressure in the cavity, and the locking force, and a method of detecting the cause of the thin flash have been developed.In this study, following results have been obtained. (1) Flow behavior of polymer melt can be obtained by the variation of the amplitude of reflected, waves. (2) Cooling behavior and the temperature distribution of plastics in thickness direction can be obtained by the travelling time through the solid and the liquid phase of plastics in the cavity. (3) The crystallinity can be obtained indirectly by measuring the longitudinal sound velocity. (4) The reflection echo ratio of ultrasonic waves at the interface between the mold surface and the metal foil placed on the mold surface is proportional to the cavity pressure. (5) The behavior of the locking force and the cause of the thin flash can be determined by measuring the reflection echo ratio at the parting surface of the mold.