GB533303A - Improvements in or relating to the spinning and winding of artificial filaments - Google Patents

Abstract

533,303. Artificial filaments &c. DU PONT DE NEMOURS & CO., E. I. Aug. 9, 1939, No. 23027. Convention date. Aug. 9, 1938. [Class 2 (ii)] Freshly formed artificial fibres, yarns, ribbons, and the like made from molten organic compositions are subjected to treatment with steam or other gas at elevated temperature and under conditions of high relative humidity between the point where they are extruded and the point where they are wound into package or other form. The treatment is carried out for a sufficient time to reduce or eliminate the tendency of the formed materials to undergo elongation upon subsequent exposure to the atmosphere. The treatment may be effected in apparatus comprising a steam treatment enclosure, a steam jacket, and means for passing steam through the jacket and for passing a small quantity of steam from the jacket to the enclosure. As shown in Fig. 1, a molten organic composition is extruded through spinneret 11 and the filaments 13 pass through the cooling tube 15. Cooling fluid passes through several conduits 19 and across the path of the filaments. It is removed from tube 15 through conduits 21. The filaments then pass through a steam treatment enclosure 23 supplied with steam from conduits 27. The filaments then pass in contact with a liquid-applying roller 35, around rolls 37, 39, and are then wound on bobbin 40. As shown in Fig. 2, the filaments pass through a tube 50 provided with sleeve 52 and steam jacket 54. Steam enters the jacket by pipe 56 and leaves by pipe 58. Some of the steam passes into the tube 50 through openings 59. The walls of tube 50 are maintained above the temperature of saturation of the steam to avoid condensation. The steam supplied to the jacket may be under superatmospheric pressure. For passing the filaments through the tube 50 when starting the treatment, fluid under pressure is supplied through tube 60. The filaments may be formed from synthetic linear polyamides, polyesters, polyethers, polyacetals, ethylene polymers, vinyl polymers, polystyrene, or polyacrylic acid derivatives. Plasticizers, dyes, pigments, delustrants, resins, and other substances may be incorporated in the filament-forming composition. Instead of steam there may be used moist air, e.g. air at 150‹F. or more and of relative humidity at least 90 per cent. In an example, polyhexamethylene adipamide is placed in a melting chamber and the molten material is pumped through a screen filter pack and then extruded to form filaments. These are passed through a cooling tube and solidified by directing air upon them. They are passed a short distance through the atmosphere and then through a steam treatment enclosure. They are stretched by drawing rolls and wound under tension. The Specification as open to inspection under Sect. 91 comprises also the treatment of cellulose derivative products obtained by melt-spinning. This subject-matter does not appear in the Specification as accepted.