Impact properties of warp knitted spacer fabrics

Spacer fabrics′ protection capabilities for human body(support) under particular impact energy were investigated.The samples were 6 warp-knitted spacer fabrics with different structures,i.e.needle pitch of shogging motion of the guide bars of spacer yarns,spacer-yarns′ diameter and fabric thicknesses were produced on double-needle-bed raschel knitting machine.The characteristics of stress,energy and energy-absorption efficiency of individual fabrics under a given impact were analyzed and the results showed that: with the decreasing of needle pitch of guide bars and increasing of spacer-yarns′ diameter,the peak stress drops,and absorbed energy and energy-absorption efficiency rise accordingly.However,fabrics with too vertical spacer yarns do not benefit for protection as they are inclined to collapse.Relatively-thick fabrics can absorb more energy and thus produce less peak stress,while moderately thick fabrics have higher energy-absorption peak efficiency.Fabrics with greater rigidity and thickness are good for body protection due to their lower peak stress,but comfortability should be taken into consideration when choosing fabric structures.