Comfort and stab-resistant performance of body armour fabrics and female vests
Creators: name: Mahbub, Rana Faruq A
Publisher: name: RMIT University
Year: 2024

description: This research reports the design and engineering of Kevlar-based stab resistant body armour fabrics and female vests, and evaluates their performance for protection and comfort especially for female police officers. Kevlar-wool woven fabric has been employed as a potential material for body armour vests. This current study investigates the thermal comfort properties of woven Kevlar-wool ballistic fabrics and commercial woven 100% Kevlar ballistic fabrics. The effects of fabric physical properties on laboratory-measured thermal comfort were analysed. In this context, their thermal comfort performance was compared, and fabric friction and surface roughness were evaluated. A water repellent treatment was applied to the woven Kevlar-wool fabric to ensure comparable thermal comfort results with the commercial 100% Kevlar. Since the commercial Kevlar fabric showed a water repellent result in the moisture management test, the effects of the water repellent treatment on the Kevlar-wool fabric were examined as well. This study also presents the fabric bursting strength and tear strength for comparison. Experimental results show a clear difference in thermal comfort properties: the Kevlar-wool fabric possesses better moisture management properties and mechanical properties than the Kevlar fabric.<br><br>Seams and stitching in body armour could affect their protective and comfort performance. Seamless technology is a method used to minimise cutting and sewing processes in making knitted garments. Seamless technology was adopted to accommodate the bust contour for female body armour designs. The 3D-knitting technology Shima Seiki SES–S.WG® and its whole-garment program were used to develop seamless female body armour vests for fit and comfort. The Kevlar-wool and 100% Kevlar fabrics were produced as weft-knit single jersey using the whole-garment knitting machine and their physical properties were measured. These properties were used to design and engineer two different styles of 3D seamless female body armour vest, the loose-vest and the bra-vest.<br><br>The knitted 100% Kevlar fabric was coated with abrasive particles to enhance stab protection performance. The stab-resistance of personal body armour standard (NIJ 0115.00) was used to determine the protection level. Single– and double-blade knives were used in this stab test. The knitted fabric mechanical properties were also investigated using bursting strength tests and stab resistance drop tests with a range of impactors. The results show that one layer of knitted Kevlar-wool, plus eight layers of knitted 100% Kevlar, and one coated layer with abrasive sand particles (a total of ten layers), passed the tests with less than 7 mm perforation at 8 J using a single-blade knife. Moreover, a combination of the knitted fabrics (Kevlar-wool, 100% Kevlar and coated Kevlar) could improve their stab-resistance. Multi-layered flexible stab-resistant vests were assembled and evaluated for comfort using a thermal manikin and sweating guarded hot-plate. The moisture management properties of the knitted fabrics were investigated. The results of this research provide a good reference for designing and engineering female body armour capable of resisting stab penetration, as well as possessing improved comfort performance.