THE MECHANISM OF SEWING DAMAGE IN KNITTED FABRICS

An investigation is reported in which penetration of the sewing needle in fabric was recorded by using a high-speed video technique. Photogr aphs show that the sewing needle penetrates the fabric structure at di fferent positions during sewing. On the basis of a simplified knitted structure, the mechanism of sewing damage is analysed. This analysis e stablishes that sewing damage in a knitted fabric is affected by the y arn structure and properties, fabric construction, and sewing conditio ns. During needle penetration in the sewing of garments, the fabric wi ll be liable to damage by a number of factors or a combination of them , namely, an increase in the yarn modulus, coefficient of friction (ya rn to yarn and yarn to needle), needle size, and yam-tension or yam-co mpression modulus. Sewing damage will be reduced with an increase in t he size of the throat-plate hole and/or the loop size of the fabric st ructure. The effects of needle points, yarn twist, and yarn tension ar e also analysed in cases in which the sewing needle hits the yarn of t he fabric, and the importance of ball-point-shaped needles for combati ng needle damage and the influence of yarn twist are demonstrated.