Dimensional and Internal Structural Design for Braided Fabric Reinforced Thermoplastic Composite

Abstract

The braided fabrics are one of the typical textiles and have been expected to be an excellent performs for the reinforcements of composite materials. Fig.1 shows schematic drawing of a braided fabric. Braided fabrics are composed of Braided Yarns (BY) oriented diagonally and Middle End Yarns (MEY) inserted into the fabric in longitudinal direction. In previous study, it was clarified that the internal structures for the braided fabric were decided with 4 parameters; area and cross-sectional shape of braiding yarns, the braiding angle and distance between braiding yarns. And it have been suggested that internal structural parameters for braided fabric reinforced composites with thermo-setting resin are possible to be predicted. However in the case of braided composites with thermoplastic resin, impregnation mechanism of thermoplastic resin with solid state is completely different from that of thermosetting resin with liquid state. In order to predict internal structures of braided composites with thermoplastic resin, it is necessary to investigate the impregnation process or mechanism of thermoplastic resin in to fiber bundles apply enough heat on thermoplastic resin to be liquid state for good impregnation especially in the case of intermediate material such as comingled yarn, and etc. The purpose of this study is to predict the relationship between dimensional and internal structural parameters for braided fabric reinforced thermoplastic composite. The braided fabric was fabricated with intermediate material such as commingled yarns. During molding with heat and pressure, effect of molding time on the mechanism of impregnation and internal structural parameters were investigated.