GB462359A - Improvements in the manufacture of moulded articles of paper and like felted materials - Google Patents

Abstract

462,359. Moulding pulp. TENNY, H. S. Sept. 4, 1935, No. 24695. [Class 87 (ii)] In the manufacture of loud - speaker diaphragms and other moulded articles from paper and similar felted materials a suction head 12 carrying a screen 19 is immersed in known manner in a pulp vat to form a pulp shape on the screen. The shape which as shown, is in the form of a cone is removed from the screen 19 by a holder 29 shown in Figs. 2 and 3. The holder comprises a cover 33 and a gauze cone 34 which fits over the screen 19. A suction pipe 35 leads into the space between the cover 33 and cone 34 and is controlled by a valve 40. The pulp cone having been sucked off the screen 19 by the holder 29 is transferred to one of the drying moulds 30, 31, 32. The cover 33 of the holder contains a baffle plate 42 which has a circular row of holes 43 formed in its periphery. When the holder with the paper cone attached is applied to one of the drying moulds the valve 40 is closed and a valve 44 opened to admit air under pressure from a pipe 46 which passes through the holes 43 and presses on the marginal portion of the paper cone and causes it to leave the cone 34 of the holder. At the same time suction is applied to the under surface of the drying mould. The drying mould is shown in Fig. 4, and comprises a hollow conical member 50 in communication with a steam pipe 53. The surface of the mould is provided with a large number of fine grooves 54 which communicate with a central suction and pressure pipe 55. The grooves 54 are intersected by a further series of circular grooves. An arm 63 carrying a ring 64 is hinged at 62 to a member 61 fixed to the mould. Attached to the ring 64 is a rubber diaphragm 65. When the paper cone has been transferred to the drying mould the arm 63 is lowered so that the ring 64 surrounds the mould and the diaphragm 65 covers the paper cone. Suction applied to the pipe 55 causes the atmosphere to press the diaphragm 65 and the paper cone against the surface of the mould. While the cone is drying on the mould other cones are being formed in the pulp vat and are transferred to other drying moulds. When the cone has dried the diaphragm 65 is swung back and air passed up the pipe 55 to detach the cone. The cone is then weighed and if of correct weight it is placed on spinning cone 66, Fig. 6, and a measured quantity of cellulosic dope introduced into the centre of the cone. Warm air from a pipe 70 dries the cone. In order that the margin of the formed cone may be thinner than the body portion the suction head 12 as shown in Fig. 3, is provided inside with a partition 77 which restricts the rate of flow of water through the marginal portion of the cone. Specification 405,979 is referred to.