The project will analyze the interactions of micro and macro changes which occur during mold filling and curing in resin transfer molding (RTM) and structural reaction injection molding (SRIM) processes. The objectives are (1) to quantify the interactions between fiber wetting and molding filling during resin injection and (2) to quantify the interactions between interface bonding and matrix reaction during curing. The knowledge gained will be used to develop and optimize several new processing techniques for mass production of continuous fiber reinforced thermoset composites. A systematic experimental and theoretical analysis will be conducted. The mold filling analysis includes microscopic flow visualization, dynamic wettability measurement, pressure profile measurement inside the fiber reinforcement, flow tracing and fiber distribution measurement in molded composites, and process modelling. The curing study includes kinetic analysis by FTIR and FTIR-PLC spectroscopy, interface strength analysis and mechanical property measurement. Fiber reinforcements used will be glass fibers in the form of continuous random mats, stitched unidirectional and bidirectional mats, and untreated and sized single fiber filaments. Resins used will be low viscosity polyurethanes, unsaturated polyesters and their hybrids. The study will allow the rational design of molded parts produced from dies and processes for the molding of composite materials and such understanding will improve the efficiency of such processes.
