Investigation of Heat Transfer and Cure During the Unsaturated Flow in Woven, Stitched and Unbraided Mats

This numerical study investigates heat generation and cure during the unsaturated flow of thermosetting resins in woven, stitched or braided fiber mats during mold filling in liquid composite molding (LCM), a popular technology to manufacture polymer-matrix composites. This study is relevant to those mats, which can be characterized as a dual-scale porous medium. An iterative, control-volume approach, based on energy and cure balances in a two-layer model representing fiber tows and gaps between tows, is used for developing discretized equations for average temperatures and cures in the tows and gaps respectively. A significant difference in the temperatures and cures of the gap and tow regions is observed. The proposed model deviates significantly from the conventional single-scale model used in most LCM simulations and highlights the need to adopt a different approach in modeling cure and temperature in dual-scale fiber mats.