Smart Machines: A New Approach for Optimizing the Residual Cooling Time in Injection Molding.

In order to realize an economical injection molding process, high process speeds and a consistently high quality of the products is necessary. A very effective possibility, which gets more and more famous, is the use of so-called smart machines and processes. If corresponding interactions between machine parameters, process variables and quality characteristics are known, the machine can design the process independently itself – a so-called self-optimizing process. This study presents a concept for optimizing the residual cooling time of the injection molding process. For this purpose, a special mold is used, which allows to detect forces initiated by thermal shrinkages on the mold core. A new evaluation method allows an automated determination of the time of the completed thermal shrinkage, which should also represent the ideal time for ejection. The principle is demonstrated using polypropylene. It is also shown that the measuring principle can be used to characterize material additives and how processing parameters influence the residual cooling time. [ABSTRACT FROM AUTHOR]