Patent GB-458535-A (GB)
Title: Improvements in or relating to artificial casings or tubes
IPC: B29C48/08
Filed: 1935-12-09
Abstract: Artificial seamless flexible tubing, including sausage casings, of regenerated cellulose, cellulose compounds, or similar film - forming materials is formed in such manner that the micellae forming the wall of the tube are directed transversely with respect to the longitudinal axis of the tube so that the tube has a strength in the transverse direction which is equal to or greater than the strength in the axial direction.  The strength in the transverse direction may be 40 per cent greater than the strength in the axial direction.  The micellae may be directed transversely by subjecting the tube, after it has been partially precipitated from solution but prior to its complete consolidation, to an increase in diameter by applying internal pressure.  The diameter may be increased by 40 per cent or more. When viscose is used, the solution may be extruded through an annular nozzle into a precipitation bath.  The coagulated tube may be cut into suitable lengths which are closed at one end and blown up from the other end with air or carbon dioxide during which operation regeneration to cellulose hydrate is performed.  The tubes are then desulphurized, bleached, and dried.  When using solutions of cellulose esters or ethers inflation is carried out after precipitation by water or other precipitant, or after partial evaporation of the solvent.  The tube may also be inflated by subjecting it to the external action of a vacuum.  The final diameter of the tube may be determined by inflating it inside a hollow body such as a pipe.  Salt solutions or water may be used instead of gas for inflation.  The increase in diameter of the tube may be accompanied by a slight longitudinal stretching.  In an example, viscose is extruded from an annular nozzle into a bath containing acid and sodium sulphate.  The coagulated tube is cut into lengths which are squeezed and closed by a clamp, inflated with carbon dioxide and regenerated by means of a spray or bath of sulphuric acid and sodium sulphate solution.  In another example, a solution of nitrocellulose in ether and alcohol is extruded through an annular nozzle into a precipitation bath of alcohol and water and the tube is inflated during production.  The tube still containing considerable quantities of solvent is removed from the bath gripped and closed to form a number of sections by clamps mounted on an endless chain.  The sections of the tube closed at both ends are cut off and introduced into a pipe which is closed and evacuated so that the air enclosed in the flexible tube sections expands them until they are in close contact with the inner surface of the pipe.  The sections are then washed to remove residual solvent, and then denitrated.  If desired, the solution of viscose or nitrocellulose or like film-forming substance may contain uniformly distributed wool or other fibres.  In this case the inflation of the tube results in the micellae and part of the fibres being arranged in the transverse direction of the tube. The Specification as open to inspection under Sect. 91 comprises also the production of tubes of transverse strength equal to or greater than the longitudinal strength from any vegetable, animal, or synthetic product.  A fibrous, or structureless cellulose sheet such as paper having the fibres or micellae oriented longitudinally may be formed into tubes and cemented in such manner that the fibres or micellae lie in a direction perpendicular to the longitudinal direction of the tube.  The tube may be parchmentized.  A hand-made paper web having no definite orientation of the fibres may be coated with a cellulose solution so that the micellae of the coating are arranged in a definite direction.  The web is then formed into tubes and cemented in such manner that the micellae are arranged transversely to the length of the tube.  A paper tube may be coated with a cellulose solution so that the micellae of the coating are arranged transversely. Two fibrous or structureless webs may be cemented in superposition so that the directions of orientation of the fibres or micellae intersect, in order to obtain a tube of equal transverse and longitudinal strength.  Three paper layers may be superposed and cemented to form a tube so that the fibres of two of the layers are arranged transversely.  Japanese paper, cotton paper, and similar long staple paper may be used.  This subject-matter does not appear in the Specification as accepted.ALSO:The Specification as open to inspection under Sect. 91 comprises the production of sausage casings of tubular form having a transverse strength equal to or greater than the longitudinal strength, from any suitable vegetable, animal, or synthetic product.  A fibrous or structureless cellulose sheet such as paper having longitudinal orientation of the fibres or micellae may be formed into tubes by bending and cementing in such a way that the fibres lie transversely to the length of the tube.  A handmade paper web having no orientation of fibres may be coated with a cellulosic solution so that the micellae of the coating lie in a definite direction.  The web is formed into tubes so that the micellae are arranged transversely.  A paper tube may be coated with cellulosic solution so that the micellae are arranged transversely. Two fibrous or structureless webs may be superposed so that the directions of orientation of the fibres or micellae intersect.  Three paper layers may be superposed to form a tube in which the fibres of two of the layers are arranged transversely. This subject-matter does not appear in the Specification as accepted.