GB1227813A - - Google Patents

Abstract

1,227,813. Printing-apparatus. POLYGRAPH LEIPZIG-KOMBINAT FUR POLYGRAPHISCHE MASCHINEN UND AUSRUSTUNGEN VEB. 25 March, 1968, No. 14191/68. Heading B6C. Stencils.-A stencil, Fig. 1a, through which ink is passed during printing comprises an ink pervious layer 2 formed by a large number of very small spherical or granular elements firmly connected together in a sintered type of formation and an ink impermeable cover layer 3 having local areas thereof removed to form the printing image. The layer 2 is supported by a flexible perforated clamping plate 1 and preferably is formed of sintered bronze particles, of metallized synthetic plastics materials or of discrete foamed particles. The layer 3 may be of chromium, applied by welding, cathodic electrode atomization or vaporization in a vacuum, or of a photopolymeric synthetic plastics material. An intermediate layer may be located between the chromium and bronze layers. The stencil may be flat or wrapped around a cylinder; Fig. 3 (not shown) depicts clamping means for the latter embodiment. Alternatively an endless stencil may be mounted by shrinkage on a cylinder (5), Fig. 2 (not shown). Rotary printing apparatus; drying apparatus. A web 14, Fig. 4, is printed in multi-colour by a plurality of cylinders 17-20 each carrying a stencil according to the invention and cooperating with a common impression roller 16. A drying device 21 is located between adjacent cylinders and a plurality of such devices is located downstream of the cylinder 20. Fig. 5 (not shown) depicts a plurality of webs (22-24) printed simultaneously by a single stencil cylinder (28), each web being dried after printing by a device (21). Each apparatus depicted in Figs. 4 and 5 may alternatively print using offset rollers.