Orientation suppression in fibers spun from polymer melt blends

The addition of very small amounts of carefully selected polymers by melt blending has been found to radically change the flow properties at spinning of conventional polymers such as polyethylene terephthalate, nylon 66, and polypropylene. This has a large effect on spun properties, especially at high wind‐up speeds. The additive polymers used have included liquid crystal polymers, polyethlene, polyethylene glycol, and nylon 66. A major phenomen is a considerable lowering of spun orientation, or wind‐up speed suppression. In order to activate the non‐liquid crystal polymers to achieve this effect special spinning conditions are necessary. The mechanism is viewed as being nonuniform extensional flow in a two‐phase system and not molecular interaction.