GB471566A - Improvements in or relating to the production of skins or tubes - Google Patents

Abstract

<PICT:0471566/IV/1> <PICT:0471566/IV/2> Ring-shaped tubes, particularly for sausage casings are made by extruding a plastic kneadable fibrous mass of animal origin through an annular nozzle whilst blowing gases into the interior of the tube being formed, and withdrawing the tube helically. The fibrous mass is extruded through the nozzle 1 (Fig. 1) and the tube is passed helically around the series of rollers 5 within the drying channel. The rollers 5 are driven from the central shaft 7. A suitable extrusion nozzle is described in Specification 433,245. In order to produce tubes of uniform wall thickness, a tube is formed by extrusion through an annular nozzle with an eccentrically-disposed core, and the tube is withdrawn so that the thickened part of the wall lies on the outside of the helix. Again, the fibrous mass may be extruded through an annular nozzle having a bevelled orifice, with or without rotating parts, and the curved tube thus formed withdrawn helically. The tubes, after drying, may be rendered resistant to boiling by treatment with water-displacing or tanning agents, e.g., aluminium sulphate, alumina, tannin or products of the slow combustion, distillation or carbonization of cellulose-and lignin-containing products. The protein-containing fibrous pastes employed as starting materials may be obtained from hide, de-tanned leather, sinews, muscles, flesh and the like by loosening or disintegrating and afterwards mechanically comminuting or shredding. The Specification as open to inspection under Sect. 91 describes also an extrusion device consisting of pots 2 and 3, Fig. 1 (Cancelled), mounted on the framework 1 and capable of being brought alternately into operative position on the table of the press 6. The fibrous mass is forced into the cylinder 17 which serves as a supply chamber and buffer. Pressure is maintained in this cylinder by means of the press 18. From the cylinder 17 the mass is fed alternately into the high pressure cylinders 27 and 28, which force it into the annular nozzle 37, consisting of a stationary part 36 and a rotatable core 38. Air is blown in through the hollow axle 40. This subject-matter does not appear in the Specification as accepted.