Abstract: The instant invention is directed to a drawn polyester yarn. This yarn is characterized by an initial secant modulus greater than 150 grams per denier/100%. The yarn may be further characterized by either a shrinkage of less than 8% or a tenacity of greater than 7.5 grams per denier. Alternatively, the yarn is characterized by a tenacity of at least 10 grams per denier, an initial modulus of at least 120 grams per denier/100% and a shrinkage of less than 8%.

Abstract: A process for spinning an organic synthetic melt spinnable polymer includes the steps of: extruding the polymer through a spinneret; passing the filaments from the spinneret through an elongated zone; maintaining the filaments at a temperature above the glass transition temperature of the polymer within the zone; and thereafter converging the filaments. Alternatively, the process includes the steps of: extruding the polymer through a spinneret; providing an elongated zone having a length of at least 5 meters or means for controlling the temperature within said zone from a predetermined maximum to a predetermined minimum; passing the filaments through the zone; and thereafter converging the filaments.

Abstract: The invention provides partially oriented polyester yarn finishes capable of substantially reducing the level of broken filaments resulting from polyester yarn texturing. Finishes of the invention are a stable oil-in-water emulsion with the oil phase including a polyester yarn texturing lubricant. The emulsion finish has a pH of at least 9.0, preferably between about 10 and about 11.5.

Abstract: A method of reducing the number of free carboxyl end groups present in a fiber-forming polymer is given whereby to the polymer minor amounts of a low-boiling oxirane compound such as ethylene oxide are added.