ABSTRACT

During both the manufacturing and subsequent processing of synthetic fibers, the proper control of yarn tension is extremely important. There are two forces involved in this control of tension. One is a mechanical driving force. The second force is a retarding, or frictional, force. The common concepts of the adhesion theory of metallic friction have been extended to include polymer friction. In all the processes fiber lubricants are necessary to control friction, wear, and static electricity. The friction must not only be controlled but must be kept at a uniform level to make a quality product. The primary characteristic of boundary friction is the tendency to stick and slip rather than to move smoothly at uniform speed. The hydrodynamic friction has the same direct relationship with the lubricant viscosity as with yarn speed. In yarn, fiber tenacity and elongation contribute most to yarn tenacity and elongation, with fiber friction and rigidities secondary in importance.