Process for continuously treating thermoplastic yarns

Abstract

An installation and process for false-twisting thermoplastic yarn are described werein the heat treating units are arranged in double rows along opposite sides of an inspection passage and within a closed chamber. The double row on one side is arranged as a mirror image of that on the other side. Each heating unit consists of a vertical, electrically heated guide for the yarn and these are arranged in vertical hot air ducts. Hot air is admitted centrally at the bottom of the chamber, and passes upwards and then downwards through the ducts to be sucked out of the chamber beneath the heating units. This exhausted air passes through devices for removing sizing agents, as by burning these, and the air then passes through a heat exchanger to a suction fan. The ingoing air is brought from outside the room in which the installation is mounted and passed through the heat exchanger to the chamber the yarns are fed downwards through one row in each double row, then out of the chamber, through cooling means and a row of twist imparters close to the adjacent side of the chamber. The yarns are then led back to the top of the chamber and down through the other row in the double row of heat exchangers, and out of the chamber to a winding-up station also close to the side of the chamber on which the double row of heat imparting units in question is located.