Forming characteristics and surface damages of stitched multi-layered para-aramid fabrics with various stitching parameters for soft body armour design

In this study, effects of different stitching parameters on formability behaviour of multi-layerd para-armide panels were investigated. Different stitching pattern namely, Uni-axial longitudinal, Bi-axial straight, Uni-axial-diagonal, Bi-axial-diagonal, Edge stitch and Unstitched were used for binding different layers. Stitch length and gap parameters were also considered while formability using different values. Diamond quilted stitched with less stitch gap and short stitch length shows severe surface wrinkling and stitch thread breakage, whereas unstitched layers show a better deformability without wrinkling and stitch thread breakage. Similarly, diamond quilted stitched shows a very less drawing-in values both in warp and weft directions. As stitch density increases, the drawing-in measurement value reduced due the formation of more rigid layer to resist the deformation. Unstitch and diamond quilted preform possess the highest and least deformation recovery percentage respectivly. Moreover, deformation recovery percentage of the layers become very less as the stich gap and stitch length reduced.