Influence of mould material in products moulded by RIM

Abstract

The growth of global competition, forces the companies to opt for new technologies, aiming at obtaining competitive, higher quality and precision products with reduced lead time to market. Rapid Prototyping and Tooling (RPT) are important technologies used for short series of products with tight specifications. Simultaneously with these techniques, it is possible to use Reaction Injection Moulding (RIM). In RIM, the mixture and the chemical reaction of the liquid isocyanate and polyol components originate the polyurethane. Since the process handles materials of low viscosity, low processing temperatures and low pressure, it is possible to use moulds with lower structural rigidity and thermal conductivity. The combined use of RIM and RPT allows for the production of high quality and complex prototypes at even lower cost. In this study the characterization of the performance of products produced by RIM is done, using moulds in several materials (aluminum, silicone and resin with graphite) and polyurethane (PUR) reactants in various percentages. The use of materials with different thermal properties affects the PUR curing process, which influence the morphology and mechanical properties of the mouldings.