Impact resistance and yarn pull-out behaviour of polymer spray-coated UHMWPE fabrics

Abstract

The impact response of polymer spray-coated Ultra-high Molecular Weight Polyethylene (UHMWPE) plain woven fabrics has been studied. Several commercial spray coatings comprising various polymers and adhesives were used on the UHMWPE fabrics. Yarn pull-out tests revealed that the pull-out force significantly increased upon coating the fabric samples, and for rubber-coated samples the peak pull-out force increased by approximately 95 times that of the neat counterpart. Subsequently, two samples that exhibited the highest pull-out load per unit of areal density were selected for ballistic testing using a 12-mm (7.05 g) spherical steel projectile. Impact velocities of the projectiles were in the range of between 140 m/s and 230 m/s. Each sample consisted of four plies of either coated or neat fabrics. It was observed that rubber-coated samples showed the highest specific energy absorption when subjected to ballistic impact and perforation. The neat fabric targets were perforated purely by a wedge-through mechanism, whereas the coated samples were perforated by a combination of wedge-through and yarn failure mechanisms, with a considerable membrane effect. The enhanced pull-out force promoted the cohesive behaviour of the fabric by diminishing the windowing effect. A novel, highly computationally efficient numerical modelling approach was proposed which predicted the residual velocity, pull-out behaviour and the transverse deformation behaviour with high accuracy.