Reaction Injection Molding (RIM)
Reaction Injection Molding
Polyurethane reaction injection molding (RIM) technology was developed in the late 1960s by Bayer AG. Since then, the technology has evolved dramatically as more and more product designers and manufacturers have learned to tap the unique capabilities and benefits of RIM for an ever-growing range of products. The universal physical characteristics of polyurethane RIM parts are high strength and low weight.
Like thermoplastic injection molding, RIM is a plastics-forming process that uses molds to form parts. But the similarity ends there.
It's helpful to view RIM not as a specific resin with narrowly defined properties, but as a process capable of achieving a broad range of properties. As its name implies, the polyurethane RIM process uses polyurethanes to produce molded parts. The polyurethanes begin as two liquid components, compared with the pellet form of most thermoplastics. These liquid components - an isocyanate and a polyol - are developed in two-part formulations, which are often called polyurethane RIM systems.
Depending on how the polyurethane RIM system is formulated, the parts molded with it can be a foam or a solid, and they can vary from flexible to extremely rigid. Thus, polyurethane RIM processing can produce virtually anything from a very flexible foam-core part to a rigid solid part. Part density can vary widely, too, with specific gravities ranging from 0.2 to 1.6.
Learn how RIM works or take a look at the RIM product spectrum for more information.