Process for producing low carboxyl polyester fibers and other articles

In the process for producing textile and industrial fibers both multifilament and monofilament or molded articles by melt extruding a polyester resin, having an intrinsic viscosity of at least 0.4 as measured in a 60/40 phenol/tetrachloroethane or 50/50 trifluoroacetic acid/dichloromethane mixed solvent at 30.degree. C. from melt spinning apparatus to form the desired article while adding to and reacting with said polyester resin, while in said apparatus for a period of from 1 to 6 minutes, at least one monofunctional epoxide of the formulas ##STR3## where R is selected from the group consisting of alkyl, cycloalkyl, alkenyl, aryl, substituted aryl and aralkyl radicals and R' is H or alkyl radical containing from 1 to 8 carbon atoms the improvement which comprises incorporating in said polyester resin prior to extrusion thereof at least one catalytic compound consisting of an alkali metal salt corresponding to the formula R(COOM).sub.n where R is selected from the group consisting of hydrogen, hydroxyl radical, alkyl radicals containing from 1 to 20 carbon atoms and aryl radical, n is selected from 1 and M is selected from the group consisting of alkali metals and in the formula MX, X = hydroxyl, alkoxyl or halide, said catalytic compound being incorporated in an amount ranging from 0.01 to 10.0 parts by weight, based on the alkali metal, per 1000 parts by weight of the polyester.