Effect of configuration in intermediate materials on textile processability by TFP technology

Abstract

Continuous fiber reinforced thermoplastic (c-FRTP) has been focused on because of not only the excellent specific rigidity and strength but also the recyclability and the secondary workability due to a feature of the thermoplastic resin as the matrix. However, unlike the thermosetting resin, it is very difficult to impregnate thermoplastic resin into continuous fiber bundles because of its high melt viscosity. In order to solve this problem, various intermediate materials have been developed. On the other hand, Tailored Fiber Placement (TFP) is a textile manufacturing technology for continuous fiber preforming. Compared to other textile manufacturing processes, the continuous fiber material can be placed in any direction according to the requirement. From this characteristic, it is possible to change the local fiber orientation in the fiber reinforced composite material, so that mechanical properties of reinforcing fibers can be utilized to maximum. Applying fibrous intermediate material for c-FRTP to TFP technology, the high cycle c-FRTP molding with optimized fiber orientation can be achieved. However, in order to prepare a preform of c-FRTP, textile processability (flexibility) is needed for fibrous intermediate materials as dry fiber. Therefore, to develop fibrous intermediate material with both better impregnation property and flexibility for TFP technology is required. In this study, the effect of fabrication condition of newly developed fibrous intermediate material called PCY (Partially Impregnated Commingled Yarn) on preforming by TFP technology was investigated. The textile processability was evaluated by measuring the deformation resistance of various PCYs. The unidirectional (UD) preforms were prepared using PCY with better textile processability and impregnation property. In order to investigate the effect of stitch yarn on impregnation property during molding, the impregnation state was quantified by cross-sectional observation of various specimens. In addition, a tensile test using UD specimen was carried out to investigate the effect of stitch yarn on mechanical properties.