Question

What are the differences between the three types of reaction injection molding processes?

Answer 1

Reaction injection molding (RIM) is a manufacturing process based on chemical reactions inside a mold. A procese reactive liquid mixture (usually polyol and isocyanate) is injected or poured into a mold where a chemical reaction takes place. After an exothermic reaction occurs, the finished part is removed from the mold. Depending on the reagents used, it may have different physical qualities.

Reinforced Reaction Injection Molding (RRIM) discloses a filler that is mixed directly into the polyol component of the foam or elastomer. The filler is typically ground glass fiber but may include other mineral substances such as mica, quartz, calcium carbonate or aluminum oxide.

Structural Reaction Injection Molding (SRIM) is a closed molding process where a preform of fiberglass or other reinforcing material is placed into a closed mold and then injected with elastomer or foam.