THE EFFECT OF YARN INPUT TENSION ON THE STRUCTURE OF PLAIN KNITTED FABRIC

Abstract

A series of experiments was carried out in order to determine the effect of the yarn input tension on the structure of plain knitted fabric. The results obtained showed that as the input tension increases, the stitch length decreases and this is mainly due to the increase in the stitch density values. The values of stitch density increase as the input tension increase because of the increases in the course count. For tighter fabrics more yarn length is needed to knit the same number of courses and wales compared with looser fabrics therefore, any increase in the input tension will increase the fabric extensibility values. This is mainly due to the increase in the stitch density. The fabric sample with the lowest stitch density has the lowest cover factor and therefore the best air permeability, i.e. air permeability has inverse relationship with fabric cover factor. The results obtained clearly demonstrated that, as the stitch density of the knitted fabric increase, the percentage weight loss increases. This trend can be attributed to the fact that, at higher stitch density levels, the abrasion force will act on a large number of stitches and therefore increasing the abrasion area. The results obtained suggest that the abrasion resistance for knitted fabrics can possibly be improved by decreasing the stitch density. It was found that as the yarn input tension increases, the fabric thickness also increases. This may be attributed to the increase in the stitch density of the fabric with an increase in the input tension. The value of pore size decreases as the input tension increases and this is mainly due to the increase in stitch density. Therefore, the fabric cover factor has inverse relationship with pore size. It was shown that an increase in the stitch density will directly increase the knitted fabric weight. Therefore, there should be a correlation between stitch density and fabric weight. It could be concluded that, the changes in basic fabric characteristics that resulting from the changes in yarn input tension have an effect on the knitted fabric pore size.