Reaction Injection Molding

Overview

Reaction injection molding (RIM) is a processing technique for the formation of polymer parts by direct polymerization in the mold through a mixing activated reaction. A simplified process schematic is shown at right. Two reactive monomeric liquids, designated in the figure as A and B, are mixed together by impingement and injected into the mold. In the mold, polymerization and usually phase separation occur, the part solidifies, and is then ejected. Primary uses for RIM products include automotive parts, business machine housings, and furniture.

Process Schematic