Effect of Lubrication on the Changes in Tenacity of Cotton Sewing Threads at Different Stages of Sewing

摘要

During the sewing process at high speeds, the needle thread is subjected to various stresses including dynamic loading, abrasion, bending through small radius of curvature, interia forces, friction and thermal loading at very high rates; resulting in the damage of threads. It is known from literature that the highest damage to the needle thread takes place during its interaction with the bobbing thread, which can be reduced, if thorough lubrication of the thread is done. Lubrication helps to mask the basic properties of the sewing thread and reduces the yarn to metal and yarn to yarn friction. In this paper, the effect of lubrication (%) on tensile strength of the sewing thread is measured at four sewing stages; i.e before sewing, after dynamic loading at the tension regulator, after passage through the needle and fabric, and after bobbin thread interaction. It is observed that as the lubrication helps in reducing the yarn to metal friction and yarn to yarn friction, the tenacity loss % decreases.