Stitched glass/PP composite. Part I: Tensile and impact properties

Stitching has proven to be an effective way to increase the through-the-thickness mechanical properties of fibre-reinforced polymer composites. However, there are rare investigations which concentrate on the stitching effect on fibre-reinforced thermoplastic polymer composite, particularly under different temperature environments. Here, we investigate the tensile and impact behaviours of stitched glass/polypropylene woven composites. The effect of various sewing threads, stitch row orientations, and spacing are evaluated. Our data indicate that the stitching in through-the-thickness direction considerably increases the impact damage tolerance especially at low temperature. In addition, glass sewing threads does not deteriorate the tensile performance of the stitched composite. The study of ductile ratio (D.R.) shows that suitable sewing thread can reduce the sensitivity of ductile behaviour of composite to the variation of temperature. A strong correlation of energy absorption with respect to sewing thread fracture work in relation to its fibre volume fraction was found.