In the Resin Transfer Molding, or RTM process, dry ( i.e., unimpregnated ) reinforcement is pre-shaped and oriented into a skeleton of the actual part known as the preform, which is inserted into a matched die mold. The mold is then closed, and a low-viscosity thermoset resin is injected into the tool. During this time, the resin "wets out" the fibers and the air is displaced and escapes from vent ports placed at the high points. Heat is applied to the mold to activate the polymerization that solidifies the resin. The resin cure begins during filling and continues after the filling process. Once the part develops sufficient green strength, it is moved or demolded.

Process Characteristics
Part cost - moderate to high Tooling Cost - low Production Rate - low Part Strength - high Parts are easily painted
Examples
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