GB491511A - Improvements in and connected with the drying of printed matter - Google Patents

Abstract

491,511. Drying printed paper. MORRIS, H. N. March 3, 1937, Nos. 6301 and 26599. [Class 34 (i)] [Also in Group XVI] Paper before or after printing is heated or dried by direct contact with superheated steam or other inert vapour at such a temperature in relation to the speed of movement of the paper that volatile constituents of the printing ink are evaporated instantaneously. Paper from a printing machine A is treated with superheated steam from nozzles 12, Fig. 7, in a vertical or horizontal drying chamber 13 previously heated to avoid condensation by a zigzag steam pipe 7 or other heating means on one or both sides of the chamber. The inlet and outlet sides of the chamber are practically closed by the supporting rollers 5, 6 of the paper. The low pressure steam may be superheated before entry or by the heating means 7. The paper may be treated in a similar chamber C (not shown) before printing, the chamber C being closed on its inlet and outlet sides by pairs of rollers between which the paper is fed. For printing on both sides each printing machine is followed by similar drying chambers 13 and may also be preceded by similar chambers C. For 3-colour printing on both sides of the paper, six printing machines, A, A<1> ... A5, Fig. 5, are followed by drying chambers B, B<1> ... B<5>, pre-treatment chambers C, C<1> being inserted before printing on each side of the paper. Rollers 5a, 6a in the drying chambers B ... B<4> only engage the printed paper at its edges. The apparatus may be re-arranged to print each side of the paper alternately until the 3 colours are applied to both sides.