Reaction Injection Molding Flashcards
What is RIM?
Two highly reactive liquid monomers that are carefully metered, brought together in a mix head, and
immediately injected into a heated mold under low pressure.
What are the variations of resin types?
Reinforced reaction injection molding (RRIM) - fillers (including chopped glass, carbon/graphite fibers,
calcium carbonate and other type of fillers) can be incorporated into one or both monomers
Structural reaction injection molding (SRIM) - reinforcement placed in mold before injecting the
reactive liquid monomers
What are the advantages and disadvantages of RIM?
many of the same advantages/disadvantages as RTM process, differences with RTM process is that
resin builds viscosity rapidly (higher average viscosity during mold filling), applications must be simple
geometries, SRIM preform must be less complex and lower in reinforcement content, parts do not
normally flash out of mold parting line sufficiently to require sealing beyond metal land area or a pinch
off around perimeter of part (low viscosity of RTM resin requires gasket or O-ring)
