Light Resin Transfer Molding

Light RTM is a closed mold system that consists of an “A” side base mold and a semi-rigid fiberglass “B” side mold or counter mold. The mold flanges incorporate seals that create an air-tight seal when the counter mold is placed on the base mold and vacuum pressure is applied. The laminate stack of fiber reinforcements are placed in the mold and the tool set is closed. Vacuum clamps the molds together.  As vacuum pressure is applied to the sealed mold, catalyzed resin is pumped into the mold through ports and a resin runner incorporated in the counter mold. Once the resin is cured, the counter mold is removed and the part is de-molded from the base mold.

Light RTM is a versatile manufacturing process that can increase productivity with mold cycles as fast as twenty minutes using several base molds and a single counter mold. Light RTM also produces finished surfaces on both sides of the part, reduces labor costs, enhances dimensional stability, and improves process control. Because it is a closed mold system, Light RTM greatly reduces Hazardous Air Pollutant (HAP) emission and improves shop working conditions. While Light RTM can be a real improvement over open molding, the tooling requirements must be considered. A tool designed for open mold may not be suitable for closed mold without some modification.

Before starting a LRTM project, consult with a Composites One technical support manager who can assist in all aspects of mold design, equipment and products to insure a successful closed mold process.

Reusable Bag Molding, also referred to as Closed Cavity Bag Molding or CCBM, is a simple, low-cost closed mold process that combines the benefits of Light RTM and Vacuum Infusion Process.

To see more videos of Light RTM visit the Closed Molding Knowledge Center.