| 摘要 |
1,120,786. Mist-spinning polyacrylonitrile filaments. MONSANTO CO. 11 Oct., 1965 [12 Oct., 1964], No. 42987/65. Heading B5B. A process for spinning continuous aorylonitrile polymer and/or copolymer filaments is characterized by spinning an acrylonitrile polymer and/or copolymer filament-forming solution to form continuous filaments, and successively advancing the filaments first through a mist filled semi-coagulation zone and thence through a liquid coagulation bath. Thus in apparatus as shown, the solution is extruded through a spinneret 10 into a coagulating bath 12 to form filaments, the spinneret being enclosed in a chamber 22 and positioned at a level from ¢ inch to 4¢ inches above the coagulating bath, an atomized fluid being introduced into the chamber to establish a mist atmosphere, by means of spray nozzles 26, and filaments after the mist treatment are passed through the coagulating bath 12 and are withdrawn over a pair of bars 28 and via stripper bar 30 before passing over take-up rolls 32. A clearance is provided around round arm 20 at opening 18 and between cylinder 14 and the bath 12 to permit the exhausting of air from chamber 22. The chamber remains completely saturated with the atomized liquid at all times so that all surface areas of the filament are exposed to the mist atmosphere. Filaments of polymers and co-polymers of acrylonitrile may be so spun, using a fluid spray of water, or dimethyl acetamide, or of a mixture of water and dimethyl acetamide. The provision of the mist atmosphere makes possible the imposition of a greater drawing force on the filaments in the jet stretching stage than is possible by conventional dry jet wet spinning techniques. Suitably, the fiaments are withdrawn from the coagulation bath at a rate producing a jet stretch of from 1.0 to 6.5 times. An additional stretch of e.g. 1.5 to 6.2 times may be provided during washing. |
