POLYESTER YARN'S MAKING METHOD

摘要

The method treats polyester yarns with an alkali attenuating process to form fine irregularities on the yarn surface for better color setting and clarity. When reacting a dibasic acid having terephthalic acid as the principal component, or an ester forming derivative of the dibasic acid, with at least one of alkylene glycols to synthesize polyester, the reaction mixture is arranged to contain a 5-valent phosphorus compound having thiophosphoryl group in 0.1-4 mol% to the dibasic acid and the total equivalent of metal to the phosphorus compound in the ratio of 0.5-3.5 times so that the phosphorus compound and metal compounds being added without advance reaction continuously synthesize polyester chip to be dried to 0.003% water content for use in known process of yarn production.