GB1216249A - Pulp-moulding method - Google Patents

Abstract

1,216,249. Moulding pulp slurries. FIBERS Inc. 18 June, 1968 [5 July, 1967], No. 28941/68. Heading B5A. Fibrous articles are moulded from pulp slurries in water employing foraminous die assemblies 40 which are sequentially displaced on to a perforated table 10 covered with a perforated flexible cushion 35; a deckle 50 is lowered to sealingly rest on the marginal walls 42 of the die 40 and pulp slurry is introduced, via a valve 60, to be diffused over the die 40 by a diffuser 64 until the die is covered; fluid is then withdrawn to deposit pulp on the die 40 by the application of vacuum through the die 40 and table 10, via a valve 30; the deckle 50 is then raised and is subsequently lowered to clamp over the die 40 a thin rubber membrane 76 which has bean unwound from a spring return roller 74 by a ram-actuated frame 70. Continued application of vacuum draws the membrane 76 into pressure applying contact with the pulp deposit on die 40 whilst fluid withdrawal therefrom is simultaneously continued; the deckle 50 is then raised and the blanket 76 stripped from the die 40 by a peeling action obtained by maintaining the vacuum during retraction of the frame 70. In an alternative method of charging the deckle 50 with pulp, water is initially admitted thereto from the underside of die 40 to the level WL, via a valve 28; pulp is then introduced into the water through valve 60 to the level FL, whereby the pulp is diffused through a greater quantity of water to enhance the uniformity of deposition thereof on the die 40. The die 40 with the pulp deposition thereon is displaced on to rollers 47 by the next advancing die 40 and the pulp layer either air dried on the die or by passing the die through a hot air stream oven. The shaping element of the die 40 comprises a Fourdrinier screen.