| 摘要 |
1,201,830. Coating process and. apparatus. KALLE A.G. 17 Dec., 1968 [18 Dec., 1967], No. 59899/68. Headings B2L and B2E. [Also in Division D1] . The interior surface of a flexible tube, constituted by regenerated cellulose, is coated by a method wherein a quantity of liquid, which wets the interior and is capable of producing a non-tacky coating thereon, is held within a section of the tube, the tube is led vertically upwards while the liquid is confined at a lower fixed position, the rising wetted interior surface is maintained extended by gas pressure within the tube adjacent the liquid-filled section, and conditions are established whereby the coating is produced from the liquid retained upon the wetted surface. As shown, uncoated tube S is drawn from a reel 1 and the coated tube is wound on a reel 2, the tube passing intermediately between two pairs 3, 4 and 7, 8 of nip rollers, and therebetween being distended by compressed air. After passing the rollers 3, 4 as a horizontal run the tube is guided into the vertical ascending direction by a guide roller 5, the coating liquid D extending from the rollers 3, 4 to a point above the roller 5. The internally-coated tube passes through a heater 6 is guided downwardly by roller 9, then passes through a second heater 10, and finally through a humidifier 16 before reaching the rollers 7, 8. A cable 15, trained over pulleys 11, 12, 13, 14 and passing through the heaters 6, 10 and above the roller 9, is adapted as a guide for the leading end of tube S. As an example in the production of artificial sausage casing, long-fibred manilla paper is continuously formed into a tube, the longitudinal seam of which is closed by an applied viscose thread. The tube is treated with viscose containing 7 per cent cellulose and 5.7 per cent caustic soda solution and having a salt index of 2. The viscose is then precipitated in an aqueous bath containing 8 per cent of sulphuric acid, 15 per cent of ammonium sulphate and 10 per cent sodium sulphate, and is thereby regenerated into cellulose. The tube is then desulphurised and passed through a plasticizer bath. The inside is coated with a lining of a copolymer of about 90 parts by weight of vinylidene chloride and 10 parts by weight of methyl acrylate.
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