Study On High Strength Nylon Blended Yarn And Fabrics For Vocational Smock

China has become the world's largest producer of CPL(caprolactam),PA6 and downstream products,and the nylon 6 fiber industry chain has become increasingly mature.The high-strength nylon 6 fiber has excellent performance and relatively low price,which has the possibility of civilian product development.The highstrength nylon 6 staple fiber is used and the matching spinning and weaving processes are studied to prepare high-strength nylon/cotton blended yarns and fabrics,in order to develop an upgraded product for vocational smock fabrics with durability and comfort and provide reference for the consumption upgrade of the vocational smock industry.The following conclusions are drawn:(1)According to the characteristics of high-strength nylon staple fiber,aiming at the difficulties arising from high-proportion(?60%)high-strength nylon blending with cotton,corresponding technical measures are taken and spinning process is optimized.Finally,high-strength nylon/cotton blended yarns with different linear densities and blending ratios were successfully spun.Yarn performance test results show that high-proportion high-strength nylon/cotton blended yarns have high breaking strength,breaking elongation and breaking work,and the yarn evenness and hairiness are also excellent.(2)The theoretical model of blended yarn strength and elongation is used to explore the influence of blending ratio on the strength and elongation of high-strength nylon/cotton blended yarn.It is found that there is a critical blending ratio when high-strength nylon and cotton are blended,and the relationship curve between the breaking strength of the blended yarn and the blending ratio is highly consistent with the theoretical prediction curve,but the breaking elongation curve has a difference in the rate of change.It is proved that the three-stage characteristic of the relationship curve between the elongation at break and the blending ratio of the high-strength nylon/cotton blended yarn is remarkable,and the specific performance is that the first and third stages are gentle,and the second stage increases sharply.In order to ensure the higher breaking strength and stable elongation of high-strength nylon/cotton blended yarn,it is necessary to avoid the interval around 30%-40% critical blending ratio.In the range of 40%-100% nylon blending ratio,the breaking strength of highstrength nylon/cotton blended yarn is greatly improved compared with ordinary nylon/cotton blended yarn,reaching the excellent product level of FZ/T 12052-2016 "Nylon/cotton blended natural color yarn".(3)At the range of large and small twist coefficients,the effect of twist coefficient on the properties of highstrength nylon/cotton blended yarns is explored.According to the test results,the changing trend of breaking strength,breaking elongation and hairiness index(?3mm)with twist coefficient in large and small ranges is analyzed.Finally,it is determined that the preferred twist coefficient of each ratio of high-strength nylon/cotton blended yarn is 390-400.(4)The blended yarns with appropriate blending ratio and twist coefficient are used to weave high-strength nylon/cotton blended woven fabric for vocational smock.The performance of fabric are explored,and compared with the vocational smock fabric currently on the market.The test results show that the developed high-strength nylon/cotton blended khaki fabric has excellent tear and abrasion resistance,as well as good strength and elongation properties and air and moisture permeability.The tearing strength of N/C 20/80 is 1.5 times that of cotton fabric;the abrasion resistance is better than that of TC fabric,which is nearly 4 times that of cotton fabric;the bending stiffness is less than that of cotton fabric,but the bending recovery performance becomes worse;the moisture permeability is equivalent to cotton fabric.The breaking strength of N/C 50/50 is far superior to that of cotton fabric,which is equivalent to TC fabric,and the elongation far exceeds that of cotton and TC fabric;the tearing strength is more than that of TC fabric and 3 times that of cotton fabric;the abrasion resistance is respectively 7.9 times and 2.3 times of cotton fabric and TC fabric;bending stiffness is less than cotton fabric,and bending recovery performance is better than cotton fabric;moisture permeability is slightly lower than cotton fabric,but better than TC fabric.Compared with N/C 50/50,N/C 60/40 has further improved breaking strength,tearing strength and abrasion resistance,but more obvious fuzzing and pilling and decreased air and moisture permeability.The raw material cost of high-strength nylon/cotton fabric is similar to that of cotton fabric,while the raw material cost of TC fabric is about 0.36 times lower than that of high-strength nylon/cotton fabric.