RIM—See Reaction injection molding

Rigid insulation foam, 206 Rigid isocyanurate foams, 226 RIM. See Reaction injection molding (RIM)... 

RCM. See Ring-closing metathesis (RCM) Reaction by-products, removing, 83 Reaction extrusion, 204 Reaction index, 237 Reaction injection molding (RIM), 205 Reaction-in-mold (RIM) nylon, 149 Reaction kinetics, 76, 77 Reaction mechanisms, polyesterification, 66-69... 

The third impregnation method, which is often referred to as injection or reaction-injection molding (RIM) pultrusion, employs a different kind of die. Unimpregnated reinforcement is guided into a narrow opening in the die, which widens into a cavity further downstream where the resin is injected under pressure (see Fig. 11.2). The cavity, which is maintained at a temperature that ensures that the resin does not start crosslinking prematurely,... 

The late 1950s saw the emergence of cast elastomers, which led to the development of reaction injection molding (RIM) at Bayer AG in Leverkusen, Germany, in 1964 (see Plastics processing). Also, thermoplastic polyurethane elastomers (TPUs) and Spandex fibers (see Fibers, elastomeric) were introduced during this time. In addition, urethane-based synthetic leather (see LEATHER-LIKE MATERIALS) was introduced by Du Pont under the trade name Corfam in 1963. 

Another important use is the fabrication of plastics by RIM (reaction injection molding) (see Figure 3.11), which exploits the very fast reaction which can be... 

Applications for hard RIM products are mainly large automotive parts, such as front and rear bumpers, and rocker panels (see Figure 1.135). The most frequently used materials are polyurethanes reinforced with milled short fibers, which are processed in the so-called RRIM process (Reinforced Reaction Injection Molding). The short fibers increase the stiffness and decrease the thermal expansion in the case of temperature changes. They are abrasive, therefore the molds are made from steel (in small series also aluminum). 

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