Abstract
In order to know the real figure of the fabric binding by the lock stitch machine sewing, the thickness of the fabric at the seam was measured by taking pictures with an optical microscope. A new term “binding ratio” is defined, basing on the cross section of the fabric under the seam, to represent the degree of the fabric binding. The effect of the thread tension and the stitch pitch on the binding ratio was discussed. The effects of the difference of fabrics and the difference of sewing threads were also discussed.
The main results obtained are as follows :
1) Pressing of the fabric by the presser foot and the sewing thread has a great influence on the fabric binding, besides the binding by both sewing threads.
2) By the machine sewing under the same static needle thread tension, the silk sewing thread binds the fabric stronger than the cotton sewing threads.
3) There is a general relation, which could be shown by one equation, between the “binding ratio” and the needle thread tension.
