Patent GB-475534-A (GB)
Title: Improvements in or relating to the manufacture of reinforced seamless-matrix tubes from cellulose derivatives
IPC: B29C48/09
Filed: 1936-05-22
Abstract: Apparatus for the continuous manufacture of sausage casings and like tubular structures of the type in which a paper base is impregnated with cellulose derivative, comprises a tubular mandrel H to the upper part of which the paper strip G supplied from a roll G<1> is fed, a ring J surrounding the mandrel and serving to bring the strip into tubular form, a device such as nozzle K for applying a solution of a cellulose derivative, and a bath B for precipitating the cellulose derivative and into which the mandrel <PICT:0475534/IV/1> <PICT:0475534/IV/2> <PICT:0475534/IV/3> <PICT:0475534/IV/4> <PICT:0475534/IV/5> <PICT:0475534/IV/6> depends.  As an alternative, the coating device may be placed in the interior of the tube, the construction of the mandrel being suitably modified; and in a further alternative construction, the coating device is situated at a point in advance of the mandrel. In the construction shown in Figs. 1 and 4, the mandrel is supported by a bracket 1, and above the forming ring J there is provided a nozzle I for applying adhesive to the overlapping margins of the tubular paper strip.  This device which is shown in Fig. 6, consists of an adjustable deflector 19 for temporarily lifting the outer margin of the strip and an adhesive-applying nozzle 25 having its jet opposite a recess 18c on the face 18b across which the other margin of the strip moves; the nozzle is located in position by adjusting screws 28, 33.  At about the level of the ring J and coating nozzle K, the mandrel which is generally of tubular form, is fitted with a flanged sleeve 3, Fig. 10, so as to provide an internal support for the tube during the pasting and coating operations, the latter being performed by supplying coating solution to an annular nozzle 35, closely surrounding the tube and mandrel.  The mandrel at its lower part continues to support the coated tube until it reaches the precipitating bath, and in order that precipitation should take place within the tube the mandrel is fitted with inlet and outlet pipes 9, 10, Figs. 10 and 11, for the supply and withdrawal of the necessary liquid, the inlet pipe ending at a point well below the level of the bath, and the outlet pipe entering a cup 10a, the upper edge of which is slightly above the liquid of the external bath.  At this point lateral openings 6a in the mandrel permit the internal bath to have free access to the inner wall of the tube, so supporting the latter. The lower extremity of the mandrel consists of a blade 8, Fig. 11, which serves to flatten the tube so that it may pass round the roller B<2>, Fig. 1; from this point the flattened tube is led to the main driving roller D and thence to the washing, purifying &c. baths C<1>, C<2>, &c. As shown in Fig. 12, the mandrel may be equipped so as to permit the coating solution to be supplied to an annular nozzle 40 by means of which the interior of the tube is coated with solution; the nozzle is situated at the lower part of a tubular section 39 closely fitting the paper tube; opposite the nozzle and external to the tube, there may be provided a supporting ring 43, and below the nozzle and inside the tube a spreader 42.  In the case of apparatus in which the coating solution is applied to the strip previous to forming into a tube, the coated strip may first be passed through a drier, later the dried coating may be softened at the pasting point by a spray of solvent, and an external coating device may be included as in the form described above or alternatively, the drier may be omitted, and the external coating device replaced by a smoothing ring. Specifications 386,644 and 475,535 are referred to.