Selection of Unsaturated Polyester Resins for Closed Resin Transfer Moulding Processes

In this paper three commercial unsaturated polyester resins of wide use in Colombia are analyzed and it is evaluated the convenience of their use in resin transfer molding processes according to viscosity and reactivity criteria. The resin viscosities are compared between 15 and 50°C, in the same way as the reactivity by mean of the curing curves at room temperature, using catalyst at 1, 1.5 and 2%. In agreement with the results, it was determined that some resins are suitable for RTM process, because of their appropriate viscosity, consistent reactivity and curing velocity. These features are of great importance in the unsaturated polyester resin selection, according to conditions of closed mold processes.