Thermal injection of thermoplastics. Basics

In the injection molding process, thermal phenomena are often the slowest, and it is they which essentially determine cycle times, and therefore the operating cost and profitability of the process. In practice, the cooling time of an injected part often corresponds to the longest phase of the molding cycle.

Technical and economic control of the injection process requires knowledge of thermal phenomena during the molding cycle. In this article, we present the various aspects of heat transfer during the thermoplastics injection process.

We deal with the cooling of parts and tools. We also introduce less conventional notions of the trade-off between heating and cooling of the polymer during mold filling, and notions of the thermal stability of tooling. Many of the results presented in this article are based on concepts developed in .