Abstract: This invention discloses a process for crystallizing polyester granules having a bi-component structure consisting of a thin crystalline skin and an essentially amorphous interior. The crystalline skin prevents the granules from sticking together in hot post-crystallization processes such as solid state polymerization or melt extrusion. The amorphous interior of the polyester granules facilitates a melt extrusion process by allowing lower melt temperatures and extruded products of improved uniformity.

Abstract: This invention discloses an improved process for manufacturing polyester monofilaments in the diameter range 0.1 mm to 0.3 mm with monofilament properties designed for use as the load-bearing, machine direction filaments in papermakers forming fabrics. The properties of the polyester monofilaments of this invention include a high tensile modulus, a low shrinkage, and control of monofilament diameters within .+-.3%. Process steps include the use of low viscosity polyester granules of Intrinsic Viscosity between 0.5 and 0.6, granules with crystalline skins and amorphous interiors, a low extrusion temperature, and spinneret orifices of cross-sectional area 30% larger than prior art. 1,000 kilograms of polyester monofilaments of uniform diameter may be produced using this improved process without changing the spinneret.

Abstract: A papermaker's fabric woven from uniformly precoated, totally encapsulated monofilament yarns is disclosed. The yarns are coated prior to the weaving of the papermaker's fabric in order to impart anti-sticking characteristics to the papermaker's fabric. The coatings may be such that thickness of the machine direction yarns is different than the thickness of the cross-machine direction yarns.