GB926662A - Improvements in printing presses - Google Patents

Abstract

926,662. Printing machines. SUTCLIFFE, SPEAKMAN & CO. Ltd. Dec. 29, 1959 [Oct. 2, 1958 (2)], Nos. 31551/58 and 31553/58. Class 100 (2). A printing press comprises guide-rollers so disposed that a web to be printed is caused to follow an S-shaped path through the press to present opposite sides successively to printing cylinders, suction means which withdraw air from the areas adjacent to the printing positions immediately after printing, means for directing warm, hot and cold air in zones successively on to the web after printing, means for directing steam into these zones and additional suction means for withdrawing and re-circulating the air from these zones. As shown, Fig. 1, a web, indicated by the chaindotted line, is fed into the press at the lower left-hand corner where it is printed on one side by a printing cylinder 19 and impression cylinder 18. After leaving the cylinders 18, 19 the web is fed horizontally and then upwards round a succession of driven rollers 5 and then back into the nip of a second printing couple 21, 22 which prints the other side of the web. After the second printing operation the web is guided first upwards and then horizontally around further rollers 5 and finally out of the press. The two series of rollers 5, i.e. those disposed before and after the second printing couple, are enclosed by hoods 10, 6 respectively the hood 6 consisting of two parts 8, 9 and the hood 10 consisting of two parts 11, 12. The hood parts are pivotally mounted on the machine frame and can be swung away from the rollers 5 by hydraulically operated means including linkages 13, 14, 15, 16. Jets 23, Fig. 3, are mounted within the hoods, through which jets heated air is directed at an angle on to the printed side of the web as it passes over the rollers 5. Jets are also mounted in the hoods which direct cold air on to the web at positions beyond the positions of application of the heated air. In those portions of the hood parts 8, 11 immediately adjacent to the printing couples suction means are provided; the air drawn from these areas contains the major part of the solvent in the ink and this solventladen air is passed to a solvent recovery plant. Suction means are disposed at the back face of the web as it passes through the warm, the hot and the cold zones of the two hoods and the air drawn from these zones is recirculated through the plant. In the warm and hot zones of the hoods 6, 10 dry steam is directed at the web through nozzles 24, the steam having the effect of improving the evaporation of solvent from the web. Specification 916,972 is referred to.