CAVITY TEMPERATURE - IMPORTANT PARAMETER IN THE INJECTION-MOLDING PROCESS

The paper stresses the importance of cavity temperature in the injection molding process of thermoplastics. From the study of the temperature field in the mold, it follows that there is no such thing as a uniform mold temperature. The heat balance equation for the injection mold is discussed in detail. It shows that the sum of the heat exchanges during the cycle equals zero. There is an extensive explanation of the heat transfer from the melt to the mold, the heat exchange with the environment, and between the heat exchange medium and the mold. New criteria are given for the cavity material selections. The cavity temperature is a complex function of static and dynamic parameters and should be kept constant in the equal parts of the cycle. This demands a new way of regulating the temperature. Copyright © 1979 Society of Plastics Engineers, Inc.