Curved sheaths, for sausage casings, made from synthetic pipes - wound on heated arbors and heated locally to set

摘要

Curved sleeves cut from a spirally coiled pipe of synthetic material to be used as casings for sausages, are produced by filling the tube with a gas, such as air, sealing both ends, and winding the tube on to a rotating, heated arbor. As the spirals are formed, they are heated locally on their outer surfaces. The tube is held under some tension whilst it is being wound on to the smooth rotating arbor. A much longer length of tube can be wound into a coil at high speed, whilst ensuring greater uniformity in the product. The expansion of the air inside stretches the outside of the sleeve and presses the inside against the arbor. Too great a shrinkage and thickening is prevented by the initial tension whilst the sleeve is being wound.