Abstract: An improved process for manufacturing highly uniform industrial yarn which exhibits high tenacity, high modulus and very low shrinkage which comprises melt spinning polyethylene terephthalate into spun filaments and subsequently drawing the spun filaments in a heated zone to a draw ratio of at least about 1.05:1; wherein the spun filaments have a birefringence of at least about 0.075 and a crystallinity of at least about 10%; wherein the spun filaments are in the heated zone for a residence time of at least 0.3 seconds; and wherein the yarn in the heated zone is at a temperature which is between the glass transition temperature and the melting temperature of the polyethylene terephthalate.

Abstract: Industrial yarn is used as a reinforcement in a wide variety of manufactured articles, such as conveyor belts, drive belts, V-belts, seat belts, hoses, tires, and the like. It is often important for the industrial yarn to have high tenacity, high modulus and dimensional stability. The present invention discloses an improved process for manufacturing highly uniform industrial yarn which exhibits high tenacity, high modulus and very low shrinkage. The present invention more specifically discloses a process for manufacturing industrial yarn having high tenacity, high modulus and low shrinkage which comprises melt spinning polyethylene terephthalate into spun filaments and subsequently drawing the spun filaments in a heated zone to a draw ratio of at least about 1.05:1; wherein the spun filaments have a birefringence of at least about 0.075 and a crystallinity of at least about 10%; wherein the spun filaments are in the heated zone for a residence time of at least 0.

Abstract: A method of vulcanizing a tubular article by extruding a sheath of unoriented polyethylene terephthalate about the article followed by quenching the sheath to an amorphous state. The sheathed article is then subjected to vulcanizing conditions in order to convert the sheath from the low density amorphous state to the higher density crystalline state, thus compressing the article to effect a smooth finish.

Abstract: Wire which has been coated with a polymeric material is useful in a wide variety of applications. One such application is as a winding for electrical equipment such as motors, transformers, magnetic coils, relays and the like. Generally, coated wires of this type have been prepared by coating the wire with multiple layers of a solution of the coating material. It has been determined that metal wires can be satisfactorily coated with a specific type of thermoplastic composition in a single layer without using solvents. This process utilizes a tubing type cross-head die with the thermoplastic composition comprising a mixture of 80% to 99% by weight polyethylene terephthalate and from 1% to 20% by weight of polyethylene, polypropylene, or a mixture thereof.

Abstract: A process and apparatus for manufacturing a polyester container having good clarity and dimensional stability and which can be used in hot-fill food package manufacture and/or in making a container for reheating or heating the contents within. In particular, this process and apparatus is a deep stretch-forming technique for preparing biaxially oriented, heat set, sealable containers of high molecular weight polyethylene terephthalate. The process comprises deep drawing a preheated sheet of the polyester into a heated female cavity by means of a male plug. The part is heat set against the female cavity, and cooled against the male plug which is used as a constraint. The part is subsequently removed from the male plug.