Patent GB-696286-A (GB)
Title: Improvements in or relating to a method and means of producing artificial sausage skins
IPC: B29C48/05
Filed: 1950-02-17
Abstract: <PICT:0696286/IV (a)/1> <PICT:0696286/IV (a)/2> <PICT:0696286/IV (a)/3> A water-containing swollen fibrous mass of animal origin is extruded from an annular nozzle to form a tubular film, a liquid such as an oil and water emulsion is applied to the inner wall of the freshly formed tube, the tube is collapsed and deposited in the form of a flat band on a support having a surface which ensures good adhesion and subsequent ready withdrawal, and the collapsed tube is dried and hardened.  The thin-walled product may be used as a sausage skin.  The support may be a flat slab, an endless belt, a roller or a drum, but it is preferred to coil the collapsed tube in the form of a spiral with the convolutions out of contact with each other on a rotating tube or drum guided past the annular extrusion nozzle.  In continuous processes the collapsed tube or band may be passed on to a large drying <PICT:0696286/IV (a)/4> <PICT:0696286/IV (a)/5> drum or on to a series of conveyer rollers in a drying chamber. The support may be coated with molten wax or paraffin to prevent sticking.  If desired the freshly formed tube may be inflated with air prior to its deposition on the support, thus avoiding creasing, and the air cushion then squeezed out by rollers.  A suitable liquid for application to the inner wall of the tube is an emulsion of 10 parts of oil (peanut, paraffin) and 90 parts of water.  The swollen mass, preferably of comminuted cowskin is first shaped in a cylindrical passage of comparatively small diameter inside an annular forming device, and then extended transversely within the nozzle by passage through an annular passage of larger diameter.  As shown, (Fig. 3), the mass is delivered to an extrusion nozzle 2 through a tube 1 under pressure.  The extrusion nozzle is formed with a cylindrical passage 5 extending throughout, and into this passage there is inserted a tube 6 connected at its lower end to a piston-shaped core 7 which fits into the lower part 4 of the device.  Between the tube 6 and the lower part of the passage 5 an annular space 8 is formed.  The mass is shaped within the space 8 and extended within spaces 9 and 10. The tube 6 is rigidly held in the device by two semicircular jaws 11 and 12 each provided with a pin which engages holes in the tube 6, and is further centred within the device by four centring screws.  An air supply pipe 14 extends through the tube 6 and forms with it an annular passage 15 through which an oil-water emulsion may flow from a tank 16.  At the lower part of the piston-shaped core there is provided a recess 18 closed by a disc 20 and connected by a passage 19 to the passage 15.  The lower end of passage 15 is closed by a sleeve 25 made, for example, of rubber.  The disc 20 is secured to the core 7, and the outer periphery of the disc projects close to the inner wall of the extruded tube 22 so that the inner wall is lubricated by the emulsion as the tube is extruded.  The interior of the tube is filled with air supplied by pipes 24 and 14.  The tube 22 is led over resiliently-mounted air-removing rollers 26 and 27 and is coiled spirally as a flat band 29 on a drum 28.  The drum is rotated through flanges 30 by means of rollers 31 and is moved longitudinally by a threaded spindle 32 driving a feed mechanism which comprises cross arms 33 (Figs. 8 and 10), carrying an arm 35 rotatably mounted at the centre of the cross.  The lower end 36 of arm 35 engages in the threads of spindle 32 by means of a tooth-like attachment, and controls the longitudinal movement of the drum 28.  If desired the speed of stripping from the drum may be faster than the speed of extrusion in order to reduce the wall thickness of the tube. Specification 690,697 is referred to.