GB409548A - Improvements in or relating to the manufacture of test sheets of paper - Google Patents

Abstract

409,548. Making test sheets of paper. EHRENTHAL, B. P. VON, 10, Sieben, br³nnenpromenade, K÷then, Anhalt, Germany. Aug. 14, 1933, No. 22668. Convention date- Feb. 1. [Class 96.] A uniform sheet of paper for testing is formed by depositing paper pulp on a sieve, removing water by suction, and drying the wet pulp sheet by concurrent heating and pressure without removing the sheet from the sieve. Pulp is supplied to a vessel 1, the sieve 3 in a frame 4 resting on a perforated plate 5, the rim of which rests on a flange 7 at the top of the suction chamber 2. A flanged ring 6 fixed to the vessel 1 is pressed against the flange 7 by clamps 8, and includes an annular compartment, round a perforated part of the wall of the vessel 1, which can be connected by a two-way cock 14 to a compressed air supply from a blower 19, or to a water-pipe 16. Prior to sheet formation, the pulp is uniformly mixed by water, and then made quiescent by air bubbles, the water and air entering through the perforations 12. Suction is applied to the chamber 2 from the blower 19 through a valve 18 &c. and is maintained constant by an automatic spring loaded air inlet 22 and is indicated on a gauge 26. A cone 23 prevents water reaching the blower, the water being drained after the sheet formation, by opening an air inlet valve 25 and a drainage cock 24. The pulp sheet on the sieve 3 and frame 4 is removed and placed on a pile of wire-cloths 45 of graduated mesh and is heated by water from a container 35 passing through a hinged lid 30 which is closed on the sheet, the bottom of the hollow lid comprising an elastic diaphragm, e.g. of rubber which may be faced with wire-mesh or fabric to prevent the sheet sticking thereto, the diaphragm compressing the sheet owing to suction applied by the blower 19 to a chamber 28, also having a pressure gauge, and automatic inlet. The chamber 28 may be water-cooled by a coil 43. Alternatively, the water in the lid may be under pressure and air may be passed through tho chamber 28.