Abstract: A non-crimping polyester monofilament having an excellent resistance to abrasion and satisfactory mechanical strength and modulus has a intrinsic viscosity distribution such that the farther the location of a part of the monofilament from the longitudinal axis of the monofilament, the lower the intrinsic viscosity of a portion of polyester resin located in the part of the monofilament, wherein a peripheral part of the monofilament formed from a portion of the polyester resin having a lowest average intrinsic viscosity of 0.6 to 1.1 and concentrically surrounds a center part of the monofilament formed from another portion of the polyester resin having a highest average intrinsic viscosity, and the intrinsic viscosities the polyester resin portions for the peripheral and center parts of the monofilament is controlled by controlling the heat history of each of the portions of the polyester resin in a melt spinneret for producing the monofilament.

Abstract: A fabric material that has a high resistance to tearing and is useful for sporting goods utilizing wind pressure, for example, yacht-sails, paragliders and hanggliders, comprises a woven fabric comprising, as a principal fiber component, polyester fibers and satisfies the following specifications:(1) a basic weight of 20 to 100 g/m.sup.2,(2) a tensile strength of 30 kg/5 cm or more,(3) an ultimate elongation of 18% or more,(4) a burst strengh of 0.18 kg/cm.sup.2 or more,(5) a tear strength of 1.0 kg or more, and(6) an air permeability of 1.0 ml/cm.sup.2 /sec or lessand preferably the polyester fibers have an intrinsic viscosity of 0.7 to 0.95, an individual fiber thickness of 1.5 to 3.0 denier, a tensile strength of 6.0 g/d or more, an ultimate elongation of 20% or more, a gradient A of a stress-strain curve at a point on the curve at which the elongation of the fibers is zero, of 1.