Analysis of Flow Phenomena during the Filling Stage of CTM

Resin transfer molding (RTM) is one of the most popular polymer composites manufacturing processes because it provides the advantages of low injection pressure, fast cyclic periods, and the ability to mold parts with highly complex shapes. However, the mold-filling process may need a long time for some cases such as large parts or parts with low permeability of the reinforcement. A flexible RTM process, compression transfer molding (CTM), is developed to reduce the mold-filling time. The mold-filling process of CTM can be divided into resin-injection and mold-closing periods. Flow visualization experiments are carried out to understand the flow behavior of each period in the CTM mold-filling process. As the closing action of the mold proceeds before the resin-injection period ends, experiments are also performed to investigate the effect of simultaneous procedures on the total mold-filling time.