Molding structural reaction injection

If glass fibers are added to get reinforcement, the method is known as RRIM (Reinforced Reaction Injection Molding). Structural RIM (SRIM) is the process whereby the reinforcement fabric or mat (glass, carbon) are placed in the mold and the resin is injected to impregnate the reinforcement. 

C. F. Johnson, Resin Transfer Molding and Structural Reaction Injection Molding in Engineering Materials Handbook, Vol. 2, ASM, International, USA (1988). 

Conversion of cyclic oligomers to composite structures via Resin Transfer Molding (RTM) and Reaction Injection Molding (RIM) techniques has been demonstrated, and will be the subject of subsequent publications. Glass loadings... 

Liquid Composite Molding (LCM) is the common name for several similar processes for the manufacturing of polymeric fiber reinforced composites. Widely used processes that belong to this class are Resin Transfer Molding (RTM), Vacuum-Assisted Resin Injection (VARI), and Structural-Reaction Injection Molding (S-RIM). 

It is impossible to list representative properties for the Reaction-Injection-Molded polyurethane structural foams, because their properties can be varied over a wide range depending on the specific application. The foams can be very tough, resilient, blown elastomers or highly rigid structural foams. Furthermore, very recent develop-... 

The physical properties for Reaction-Injection-Molded urethane foam cannot readily be determined because they are, as all sandwich structures, highly dependent on the particular shape of the article and the ratio of skin to foam or, in other words, the density distribution through the part. Typical densities for these new structural foams are 30 — 45 lbs./ft.3 with average moduli of elasticity of 120,000 — 250,000 p.s.i. The compression strengths are higher than those shown in Table VI for rigid foams without skins. 

In Europe, car manufacturers first used a half product, a sheet molding compound (SMC) made of sheets of fibers pre-impreg-nated with resin. In the USA they used a different process named RIM (Reaction Injection Molding) which allowed the bumper to be painted the same color as the rest of the structure. 

The largest segment of the CASE family of polyurethanes are elastomers. Cast polyurethane elastomers reached a new dimension when high pressure impingement mixing led to reaction injection molding (RIM). This technology is used widely in the automotive industry, and reinforced versions (RRIM) and structural molded parts (SRIM) have been added in more recent years. 

Reaction injection molding (RIM) is a process where a controlled chemical reaction occurs in a mold after injection of the material components. Commercially, the process is used almost exclusively for production of polyurethane parts by injecting a two-component system of isocyanate and alcohol (Figure 14-54). Polyurethanes can be produced with a wide range of properties, from very low density foams to reinforced, structural components. RIM is widely used... 

The latest trend in foamed composites is automotive structural parts produced by the SRIM (structural reaction-injection-molding) process. The SRIM process is a method of the reactive liquid injection molding (i.e., LIM). LIM includes RIM (reaction injection molding), RRIM (reinforced RIM) and RTM (resin transfer molding). IX M (Liquid Composite Molding) is a relatively new technical term which includes SRIM, RRIM and RTM (Resin Transfer Molding). 

Furthermore, the use of chlorofluorocarbons in injection molding and reaction injection molding has resulted in more uniform cellular structure, reduced weight per unit, better... 

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