The Bundle Effect of UD - laminate Made of Friction Spun Core Yarn as Premix

Consolidation of thermoplastic unidirectional (UD) laminate with friction spun core yarns was investigated, especially the characterization of filament bundles in consolidation was analyzed. The results showed that the bundle effect was affected considerably by processing conditions (applied pressure and processing time). The boundary of the bundles was disappeared under suitable processing conditions and finally an even fiber/resin distribution could be attained. In consolidation, filament bundles getting close each other and resin flowing into the bundles occurred simultaneously, and eventually the bundles were fully impregnated by the resin. Fiber packing density in UD - laminate was the same as that of friction spun core yarn (55% - 65% in volume) and was not affected significantly by processing conditions under the current experimental conditions.