ABSTRACT
The most important reason for applying a finish to synthetic fibers is to control the tension during the spinning process, and also the friction in subsequent processing. As the yarn then passes through the actual texturing device, either a pin or a friction disk assembly, it is necessary for the yarn to have a higher friction for proper bulk development. Sometimes lubricants are selected to volatilize at one manufacturing step, leaving another component to control the tension at a later stage in that process. Mineral oil was one of the initial components used in spin finishes for fiber lubrication. Ethylene oxide–propylene oxide lubricants exhibit a wide range of fiber to hard surface friction, which varies with running speed and molecular weight. Propylene glycol dipelargonate is another ester that was designed especially for cosmetic use, but it can be useful as a low viscosity fiber lubricant.
