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: The tread reinforcing belt structure (24) of a pneumatic tire (10) has at least one belt ply (29) of flat steel wire. The belt ply of flat steel wire is stiffened by other components of the tread reinforcing structure such as belt plies of steel cables (28,30). It is especially important that the axially outermost edge portions of the belt ply of flat steel wires be supported by other components of the tread reinforcing belt structure, and that the flat wire have specific cross-sectional dimensions.