Considerations on Diameter Ratio in Commingled Hybrid Yarn for Fibre Reinforced Thermoplastic Composites

Manufacturing of lightweight structures from fibre reinforced thermoplastic composites is of great benefit. Among various manufacturing methods the usage of semi-finished products is in a high demand. To improve the mechanical properties and increase the productivity, the commingled hybrid yarn is developed recently. Among many parameters the fibre volume fraction and the diameters of reinforcement filaments and thermoplastic filaments in hybrid yarn are investigated in this paper. The target is to improve the impregnation of reinforcement by molten thermoplastic polymer. Two hybrid yarn samples are illustrated (a) high performance thermoplastic PEEK/CF and (b) standard thermoplastic/glass fibres PP/GF. The unidirectional composites samples manufactured using thinner filaments show hardly an improvement of mechanical properties within the investigated region. A new technological approach will be introduced to increase the homogeneity of PP/GF commingled yarns by online hybrid spinning.

Keywords:

fibre composites , commingled yarn , thermoplastic polymer , melt spinning