Abstract: An improvement is provided in the rapid quenching of melt-spun polymeric filaments, whereby the filaments are cooled by quenching gas that is accelerated along the threadline by being passed through a tube of smaller dimensions with the filaments before they emerge.

Abstract: Improved polymeric membranes and their method of manufacture are disclosed. The improved membranes are produced by increasing the draw ratio employed during the manufacture of the membrane. The membranes show at least substantially constant or increased selectivity and mechanical properties as the draw ratio is increased.

Abstract: Improved polymeric membranes and their method of manufacture are disclosed. The improved membranes are produced by increasing the draw ratio employed during the manufacture of the membrane. The membranes show at least substantially constant or increased selectivity and mechanical properties as the draw ratio is increased.

Abstract: A melt-spinning process for spinning polymeric filaments at a spinning speed controlled by a positive mechanical withdrawal means that increases the speed of the filaments to above 7,000 meters/minute whereby a drawing and necking down of the filaments occur below the spinning pack, directing a gas into a zone extending from the spinning pack to a location between the spinning pack and the withdrawal means, maintaining the zone under superatmospheric pressure of less than 0.03 kg/cm2 and increasing the velocity of the gas as it leaves the zone to a level greater than the velocity of the filaments to reduce the extent of necking down of the filaments.

Abstract: Spinning of polyethylene terephthalate yarn at speeds in excess of 5000 meters per minute using a gas management technique of the gas surrounding the threadline to control the temperature and attenuation profiles of a spinning threadline provides a means to produce a low crystallinity polyester yarn with a relatively high elongation to break.

Abstract: A blend of low density polyethylene and crystalline polypropylene can be melt spun at high temperature and high speed to produce a fiber. The fiber has utility as a binder fiber in nonwoven fabrics. The blend contains 5 to 35% by weight polypropylene and 95 to 65% of polyethylene.

Abstract: A blend of low density polyethylene and crystalline polypropylene can be melt spun at high temperature and high speed to produce a fiber. The fiber has utility as a binder fiber in nonwoven fabrics. The blend contains 5 to 35% by weight polypropylene and 95 to 65% of polyethylene.

Abstract: Spinning of polyethylene terephthalate yarn at speeds in excess of 5000 meters per minute and rapid quenching produces highly oriented, amorphous yarn that gives enhanced bulk on texturing.