ES376182A1 - Process and apparatus for melt spinning synthetic polymers - Google Patents

Abstract

Synthetic polymers are melt-spun through a spinneret with orifices whose centres are less than 3À5 mm. apart the filaments are cooled by a stream of gaseous cooling medium blown on to them from an angle of from 80 degrees to 150 degrees to the direction of movement of the filaments, and supplementary heat is supplied to the spinneret, the amount being regulated such that it is not less than half the amount and not more than the total amount of heat removed from the spinneret by the stream of coolant gas. The heat may be supplied by an electric heater connected to or embodied in the spinneret or by an electric radiator directed at the spinneret or directed parallel to the nozzle plate. The spinneret is preferably made of low-carbon steel having an emissivity greater than 0À3. The filaments are preferably extruded vertically downwards. The coolant is preferably air at room temperature but gases and vapours inert to the materials used for the spinneret and the filaments for example, nitrogen, carbon dioxide and sometimes steam may be used. The process is suitable for polyesters such as polyethylene terephthalate, polyamides such as nylon 6 and nylon 66 and polyolefines such as polyethylene and polypropylene. The fibres may be given a patent crimp by unilateral cooling. Specifications 1,262,811, 1,262,813 and 1,262,814 are referred to.