Pill-resistant polyester fabrics

Claim 1

An improved process for reducing the pilling propensity of a fabric comprising by weight at least 50 percent polyester staple fibers having tenacities in the range of about 2 to 6 gpd, deniers less than 3 d.p.f. and lengths of 2 inches and less, without significantly affecting either the grab strength of the fabric or the fabric dyeability or the absence of sheen in the fabric, comprising (a) atomizing an aqueous solution comprising at least 5 percent by weight of sodium hydroxide into a spray of fine particles having sizes up to 130μ; (b) applying said particles onto at least one surface of an undyed polyester fabric comprising by weight at least 50 percent polyester staple fibers having tenacities in the range of 2 to 6 gpd, deniers less than 3 d.p.f. and lengths of 2 inches and less, in an amount of said particles up to 40 cc per square meter of fabric; and, (c) applying heat to said sprayed fabric at a temperature within the range from about 115° C. to about 165° C. for a period of from about 10 seconds to about 90 seconds, to saponify, in part, said polyester fiber; wherein the improvement comprises: applying a solid deposition of about 0.5 to 4 grams sodium hydroxide flakes (76% Na 2 O) per square yard of fabric to said untreated polyester fibers having tenacities in the range of about 2 to 6 gpd, in the absence of a swelling agent; and applying dry heat; whereby said treated fabric has a pilling performance rating of at least 4 as measured by the Random Tumble Pilling Test (ASTM D 3512) after 30 minutes and after 60 minutes.