Tensile properties of GF/PP commingled yarn biaxial weft knitted fabric laminated composites

A biaxial weft knitted fabric was produced with GF/PP commingled yam and its laminated composites are fabricated through hot pressing process using different stacking configuration, i.e. [0](4), [0/90](2), [-45/45](2), [0/-45/45/90] and [90](4). The tensile properties of the laminated composites were experimentally investigated and the stress-strain curve as well as the variations of ultimate tensile strength and the elastic modulus with the fiber volume fraction were analyzed. The results have shown that there exists a big different of the tensile properties of the composites tested along and off the inserted yam directions, and that the ultimate tensile strength and initial elastic modulus are proportional with the fiber fractions. This means that the insertion of the yams enhances the mechanical properties of knitted structural composites.