Impingement mixing Curing

A semicOTitinuous manufacturing process in which two liquid compmients are metered in the calculated ratio by high pressure piston pumps, mixed by impingement mixing and injected into a mold cavity or cavities, where the reactants are polymerized or cured. The process has been used to polymerize polyamides, elastomeric polyurethanes, and polyurethane foams. 

During all experiments the resin and the curing agent were kept under a nitrogen pressure of 1.5 bar. The impingement mixing pressure was 50 bar for both components and the output was set at a total of 6 kg/min. 

Reaction injection molding (RIM) is a fast, low-pressure, low-temperature, low-cost process for one-step conversion of reactive liquids into large finished solid plastic products. Liquid polyol and liquid diisocyanate are mixed by impingement, pumped instantly to fill a large mold cavity, and polymerize/ cure rapidly to form a thermoset polyurethane product. The cured polymer may be a stiffly flexible product such as automotive bumper covers, front ends, and trim or a rigid foamed product such as furniture and housings (cabinets) for computers, business machines, TY and radio. 

The plastics polymerize after entering a mold. Mixing two or more components (additives, fillers, and reinforcements) in the proper chemical ratio is accomplished by a high-pressure impingement-type mixing head. This mix is directed into the mold cavity at low pressure, where it chemically reacts to form a plastic. The components are mixed together at a given ratio and then directed or basically poured into a mold under controlled temperature, pressure, and rate of flow. They polymerize and cure in... 

The foam-forming ingredients are carefully metered to obtain the proper ratio of reactants, thoroughly mixed by either mechanical or impingement means, then applied as a liquid, a spray, or a froth with subsequent expansion and curing. 

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