RIM Machine Design

The two metered streams are forced to impinge at high velocity to achieve good mixing. From the mix head, they flow into the mould through a runner and react rapidly to produce a solid part. Many machines possess 

Supplier Dow Chemical Mo bay Chemical Jefferson Chemical Union Carbide Davidson Rubber MC -1024 -1075 Upjohn Chemical Rimthame 65 70 BASF Wyandotte Uroflex 

The process can be broken down into several unit operations, as shown in Fig. 6.6. A necessary condition for the success of easy mixing by impingement is that the reactants each possess low viscosity also only low pressures are needed to fill the mould and this reduces the costs of capital equipment, especially for large parts, which makes RIM economically attractive compared with a typical thermoplastic injection-moulding process. A comparison of RIM and thermoplastic injection moulding is shown in Table 6.5. 

Temperature of reactants (°C) Temperature of mould (X) Injection pressure (MPa) 

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