Effect of yarn count and loop length on needle penetration force and needle cut index in single jersey fabrics

The present study embodies the sewability of single jersey knitted fabric based on needle penetration force and needle cut index. Four types of single jersey fabric, viz. 100% cotton, polyester/cotton, polyester/lycra, and cotton/lycra, are taken for investigation. The materials are prepared on circular knitting machine by varying the yarn count and loop length. The influence of various parameters, viz. type of fibre, yarn count and loop length, on needle penetration force and needle cut index have been analyzed. In addition, the influence of seam direction on the needle cut index is also studied. A 3 _ level factorial design is employed to analyse the influence of there parameters. The statistical analysis shows that yarn count and loop length has a significant effect on needle penetration force and needle cut index. It has been observed that in all single jersey knitted fabrics, cotton-lycra and polyester-lycra half plated fabrics have higher value of needle penetration force than cotton and polyester/cotton.  The test results also show that for both coarser yarn and finer yarn count, longer loop length gives a lower value of needle penetration force. The needle cut index decreases with increase in the yarn count and loop length. Also it is observed that, the needle cut index is more in wale direction as compared to that in course direction. It is also concluded that cotton fabric samples are more susceptible to needle damages as compared to their counterparts.