Rim Systems by Computer Techniques

This paper examines the problems involved in predicting the behavior of urethane foams made by reaction injection molding (RIM). In general, RIM urethane foams are formed from mutually soluble stable liquid components into a 60 pcf foam with a durometer hardness of 50D and with sufficient strength to be removed from the mold in one min or less.

Since impact resistance also is important with the materials, the property of low temperature impact is a basic selection criterion. A fundamental problem is how the desired impact resistance can be obtained without sacrificing other needed properties.

This study describes how the creation of a mathematical model, based on experimental data, can be used to predict how basic properties of RIM urethanes will change as key variables are altered.