In-plane shear properties of para-aramid (Kevlar®) fabric by yarn pull-out method

The aim of this study was to determine the in-plane shear properties of para-aramid fabrics by the pull-out method. For this purpose, Kevlar®29 and Kevlar®129 type fabrics were used. Fabric width/length ratio and the number of pull-out ends were identified as important testing parameters. After the yarn in the fabric was pulled from the top ravel region before the start of the crimp extension stage, it was found that fabric shear strength increased when the number of pulled ends increased. On the other hand, when the fabric width/length ratio decreased, fabric shear strength increased. The shear force and angle values in Kevlar®29 fabric were higher than in Kevlar®129 fabric due to high fabric density. Fabric shear rigidity was also identified for each Kevlar fabric. The number of pulled ends and the fabric width/length ratios influenced fabric shear rigidity. It was observed that the shear rigidity values in Kevlar®29 fabric were high compared to those of Kevlar®129 fabric due to high fabric areal density. Also, the shear jamming angles were found to be based on the number of pulled ends. Fabric local shearing properties could be identified by pulling the yarn ends in various regions of the fabric. This could be important for the handling of the fabric during formation. The results generated from this study showed that para-aramid fabric shear could be measured by the yarn pull-out test.