7 - Modeling, optimization and control of resin flow during manufacturing of textile composites with liquid molding

Abstract

Liquid Composite Molding (LCM) processes are commonly used to manufacture polymer–textile composites because of their low equipment and tooling costs, low pressure requirements, short cycle times, and ability to yield net-shape parts. Some variations of LCM processes are Resin Transfer Molding (RTM), Vacuum-Assisted Resin Transfer Molding (VARTM), Resin Infusion Process (RIP), and Seemann Composites Resin Infusion Molding Process (SCRIMP). LCM processes include three basic steps. This chapter highlights these steps and discusses exclusively the mold filing step. It presents the model of flow through porous media, introduces Liquid Injection Molding Simulation (LIMS), software that is used to simulate resin flow in the mold cavity, and presents a summary of its utilization in design, optimization and control studies. The chapter also presents a method to optimize injection gate location, introduces the disturbances associated with the mold filling process, and explains the major disturbance, racetracking, and the use of feedback control to offset the adverse effects of racetracking on the mold filling process. It further presents a passive control method to minimize the defect content in the composite parts and identifies the potential future research directions.