High-pressure impingement mixing, closed-mold injection, and controlled exothermic cure. The right process when surface finish, dimensional repeatability, and complex geometry are all non-negotiable.
In open-cast molding, the polymer reacts at atmospheric pressure — fine for many parts, limiting for others. In reaction injection molding, two streams (polyol blend and isocyanate) are pressurized to 1,500–3,000 psi, forced through a mix head that combines them by impingement, and injected into a closed steel or aluminum tool. The reacting polymer fills complex cavities completely, replicates fine surface detail, and demolds with dimensional consistency that open-casting cannot match.
Specify RIM when your part has tight dimensional tolerances, a visible Class-A surface, integrated structural features, or inserts that need to be molded in-place. RIM is also the right process for integral-skin parts above a certain size threshold where open-pour cannot deliver consistent skin thickness on large cavities.
Send us the drawing. We'll recommend the right process — honestly.
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