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Abstract

A process for the regeneration and further condensation of a linear polyalkylene terephthalate, which is inactive due to recondensation treatment in the solid phase, and which has a viscosity number of at least 60 cc/g, the process being conducted in two stages, at an elevated temperature, in the presence of an alkanediol, comprises, in a first stage, treating the inactive polyalkylene terephthalate at a reaction temperature of 30.degree.-80.degree. C. below its melting point, with 0.3-3.5% by weight, based on the weight of the polyalkylene terephthalate, of an alkanediol whose boiling point under normal pressure is 20.degree.-70.degree. C. above the reaction temperature, in an inert gas stream, wherein the amount of inert gas passed through per hour, measured under standard conditions, corresponds to 0.3-2 times the gross reactor volume; and, in a second stage, condensing the polyalkylene terephthalate at a temperature of 5.degree.-25.degree. C. below its melting point in an inert gas stream, wherein the amount of inert gas passed through per hour, measured under standard conditions, corresponds to 2.5-10 times the gross reactor volume.

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