Development Of Flexible Protective Layer For Safety Shoes

This work aimed at developing a textile structure to enhance the stab-resistant performance of safety shoes for protecting the feet of workers.The anti-stabbing properties of woven and knitted fabrics are optimized by using different fabric structures,yarn combinations and fabric densities.For the woven fabrics,ultra-high molecular weight polyethylene fiber(UHMWPE)was used.A plain woven structure,a four-layer laminated plain structure,a three-dimensional angular interlocking woven structure and three fabric densities were selected,and nine fabrics were produced.For the knitted fabrics,besides UHMWPE fiber,a nylon/spandex covered yarn and a low temperature melt polyester yarn were selected to form six yarn combinations.Interlock,four-course ponte di Roma,and six-course ponte di Roma structures were used as ground structures and a 1600 D UHMWPE yarn was used as in-lay yarn,and eighteen novel fabrics were knitted.A fixture and a nail were customized in accordance with the standard GB21148-2007 Personal Protective Equipment Safety Shoes and GB 21146-2007 Personal Protective Equipment Professional Shoes.The length of the nail is 72 mm,the slippery angle of the tip of the nail is 30 degrees and the elevation of the tip is 7 mm,the diameter of the tip is 1 mm.The fixture and nail were installed onto an Instron 5967 electronic universal strength testing machine.Quasi-static stabproof tests were conducted by using the machine for the woven fabrics and knitted fabrics.The stab resistance of woven and knitted fabrics was compared in terms of the stabbing force-displacement curve,unit surface density and anti-stabbing force of unit plane density and thickness.In order to better compare the performance of different samples,their test results were normalized by dividing the areal density and thickness.The experimental results showed that four-layer laminated plain woven fabrics have the best anti-stab performance with an average anti-stabbing load 220.93 N,but with big deviation.For the knitted fabrics,the six-course ponte di Roma with inlay has the maximum anti-stabbing load of 158.72 N,and it is also better than four-layer laminated plain woven fabric in terms of stabbing load and deviation.The areal density and thickness of woven fabrics increase with reed number.The areal density and thickness of knitted fabrics increase as the amount of nylon/spandex covered yarn and low temperature melt polyester yarn increases.With the increase of density and thickness of the fabric,the anti-stabbing load of the fabric increases gradually.The test results of the three-dimensional woven fabric have small deviation than those of the four-layer fabric.Selecting appropriate knitted structures and yarn materials is vital to increase the amount of UHMWPE fiber per unit volume for the development of anti-stabbing knitted fabrics.