Experimental Validation of Dependence Map based Control in Liquid Composite Molding

Abstract

Liquid composite molding (LCM) processes offer composite makers the environmental benefits realized by the closed molding process, and can provide better dimensional tolerances as well as part complexity. One drawback is the unpredictability in the flow behavior during the filling stage due to material and process variability that can result in resin void areas, or dry spots. Parts containing dry spots must be discarded, thus adding superfluous cost to the process. Flow control has demonstrated the ability to correct those flow anomalies to eliminate dry spots. Previous efforts developed a hybrid on-line–off-line flow controller for the LCM process and detailed the development and application of the methodology. In this study, the methodology is summarized, and the technique is applied in a manufacturing environment. A resin transfer molding workstation is developed and built to meet the needs of the control technique. A series of experiments with three different geometries with increasing complexity is conducted to validate the new flow control methodology. The results are compared with experiments without flow control to gauge the usefulness of the methodology proposed.