Abstract
An investigation has experimentally been made on the seam puckering and the differential feeding between upper and lower knitted fabrics from the view point of weighted factors of the sewing function (i.e., fabric feeding) and fabric properties. The experiments have revealed that ; (1) The analysis of variance has shown that the seam puckering and differential length between upper and lower fabrics after sewing are most affected by the fabric feeding mechanism. Therefore, the individual feeding of upper and lower fabric is effective to prevent fabric from these sewing defects. These sewing defects is, next to the most, affected by the fabric properties. The effects of the pressure of the presser bar and the height of the feed dog are little, although they depend on the properties of knitted fabrics and interactions are found between them. (2) Among fabric properties, elongation, friction and bending properties affect the differential feeding between upper and lower fabrics. (3) It is confirmed by the photographs that differential feeding and seam puckerings are caused by the elongation of the upper fabrics occured by the pressure of the presser foot.
