GB791402A - Improved method and apparatus for the manufacture of artificial edible sausage casings - Google Patents

Abstract

<FORM:0791402/IV (a)/1> Artificial edible sausage casings not more than 0.016 mm. thick, for use in the production of small thin sausages, are formed by the steps (carried out at not over 25 DEG C.) of soaking pieces of animal hide or skin for a long time in milk of lime, removing and water-washing them, immersing them for some hours in a dilute aqueous solution of hydrochloric acid, washing them with water until the pH of the aqueous extract is 2.8-3.4, coarsely disintegrating them by passing them between fluted rollers, further disintegrating them by passing them through perforated plates having round holes of 1 to 1.5 mm. diameter, adding water to the fibrous mass thereby formed to reduce its dry content to 8-9.5 per cent, kneading the mass until it is homogeneous, passing the mass repeatedly through plates having slots which have a length of 6-10 mm. and a width not exceeding 0.22 mm., and finally extruding the mass through an annular passage, the width of the annular passage, including the annular extrusion nozzle or die, not exceeding 0.22 mm. and the walls of the passage rotating in opposite directions about the nozzle axis. The length of the annular passage may not exceed 2.5 times the diameter of the outer ring of the annular extrusion orifice and its width may be 0.16-0.22 mm. The walls of the passage may rotate at not more than about 60-120 R.P.M. for a production rate of 6-8 metres of casing per minute. As shown in Fig. 2, the finely disintegrated fibrous mass is forced through the tube E, the tubular cavity of the tubular rotating core A and passages G into the annular chamber H between the core A and the tubular sleeve B of the extruder, which sleeve rotates in a direction opposite to that of the core and is supported in a stationary housing C. From the annular chamber H the fibrous mass is forced into the annular passage D in which, as the result of the contra-rotation of the core A and sleeve B, the fibres of the mass are oriented in two directions crossing each other. The fibrous mass is extruded from the outlet of the annular passage D to form a tubular casing which is inflated by compressed air supplied through a tube Z which communicates with an annular duct W in the fixed housing. This duct in turn communicates with the short bent portion V of the tube F which is integral with and rotates with the core A and whose other end is open and flush with the face of the extrusion nozzle. The end of the core A located at the duct W rotates in an air-tight running gland indicated generally at U and provided with resilient sealing rings T. The fixed tube E and co-operating end of the rotating core A is provided with a running gland X having a grooved sealing ring Y. The core A and sleeve B are rotated in opposite directions by means of the duplex bevel gear S.