Wetting of synthetic fibers by thermoplastic melts during capillary impregnation of filaments

A method for the determination of the rates of impregnation and wetting dur ing capillary impregnation (with a number of thermoplastics) of chemical fi ber bundles (filaments) used for the reinforcement of polymer composites wa s developed. The rate of wetting was proposed as the most objective charact eristic of wetting of a fiber surface under dynamic conditions of impregnat ion with a viscous polymer melt. Based on experimental data, the values of the capillary pressure and the parameters of wetting of carbon and heat-res istant synthetic fibers by melts of polyolefins, polyamides, and polyesters were calculated. The kinetic character of wetting and the formation of adh esive contact between the fiber surface and the thermoplastic melt is confi rmed by the pattern of changes in rigidity during filament torsion in the i mpregnation process.