TESTING AND MEASURING Influence of Process Parameters on the Curing of Polyurethanes by dielectric Measurement

The Polyurethane Reaction Injection Mol ding (PU RIM) process is currently still reli ant on a high level of know-how, both in the case of quality deviations of the pro duct and in the initial configuration of molds. PU manufacturing hardly uses the established sensor technologies that are common in injection molding. In a re search project at the Institute for Plastics Processing (IKV), the influence of the pro cess parameters component tempera ture, mold temperature, material output speed and mixing ratio on the curing be havior of compact polyurethane coating systems is being experimentally investi gated by means of dielectric measure ments. The results show that for all varia tions of the process parameters investi gated, the influence on the curing reac tion could be successfully detected.

A wide range of variants of the reaction injection molding process (e.g. closed or open mixture injection) are used for the production of compact and foamed poly urethane (PU) components. Parts are mainly used for various industries, inclu ding the transportation industry (uphols tery elements in automobiles or trim elements of trucks), refrigerator industry (insulation) and medical technology (prostheses).