GB685950A - Improvements in or relating to a process and apparatus for the production of artificial fibres - Google Patents

Abstract

<PICT:0685950/IV (a)/1> <PICT:0685950/IV (a)/2> A fibre-forming mass in solution or in molten state is extruded through a porous wall having irregular or tortuous fine passages from its inner to its outer face, thus being formed into artificial fibres. The porous wall may consist of a disc of earthenware, glass or porous metal or of other natural or artificial material. If desired it may be heated. The extrusion may be assisted by the direct action of a pulling member or gib which may be complementary with respect to the wall and thus conform thereto, or by centrifugal force. The fibres may be guided to a winding apparatus which, like the gib, may operate with a greater velocity than that at which the fibres are produced, thus stretching them. The gib may be made of leather, rubber, glass or metal and may possess a smooth surface. Suitable materials for spinning include polyamides, polyacrylates, polystyrenes, polyvinylchloride and cellulose esters. As shown (Fig. 1), a container 1 is provided with a plug 2 having a central opening covered by a porous disc 4 held in position by a tube 5 for the supply of fibre-forming material. A funnel 7 is fixed into the bottom of the container for withdrawing the fibres. The container is also fitted with suitable exit and entry pipes for solvents &c. A plate or gib 9 is mounted on a carrier 12 for movement in a vertical direction, and held in contact with the disc 4 prior to spinning. The molten polyamide or other material is supplied into pipe 5 and, on extrusion through the disc 4, the plate 9 is rapidly lowered to initiate the spinning, the fibres being passed by hand through the funnel 7 to the withdrawing reel 10 and the gib or plate 9 moved clear of the fibres. Fig. 2 shows a modification in which the fibres are extruded by centrifugal force. A drum 15 is mounted for rotation, and axially into it projects a supply tube 20 which may also be rotatable. A porous wall 22 is formed in the lower part of the tube. As the fibres are extruded through the porous wall they are entrained by the rotating drum and deposited on the circumference. Gaseous nitrogen or carbon dioixde may be used to blanket the spinning material and prevent oxidation. The Specification as open to inspection under Sect. 91 refers also to extrusion through wire screens with openings out of register, and to the extrusion of glass. This subject-matter does not appear in the Specification as accepted.