Printing machine for prodn. of pattern directly in press

摘要

A printing machine for prodn. of a pattern directly in the press, comprises: (a) a cylindrical surface (4) to be illustrated, on which the patterns are formed; (b) a coating unit (12) arranged close to the surface (4), to be moved over the surface (4) and to provide this with a thin layer (17) of changeable material, to convert the surface or regions of the surface from a first water-sensitive property to an opposite water-sensitive property; (c) a drying unit (13) for the changeable material, close to the surface (4), able to treat the material until it is dry; (d) a unit (14) to change the layer (17) on the surface (4) to form a required pattern of regions carrying printing ink and regions repelling printing ink; (e) a unit (6) for coating the layer of material (17) with printing ink, to form a coloured picture; (f) units (2, 3) to transfer the picture to paper (1); and (g) a cleaning unit (7) arranged close to the surface (4) and able to clean the surface (4) which carries (part of) the changeable material after the transfer of the pattern onto a rubber cloth cylinder (3). Pref. the layer (17) has regions of hydrophobic or hydrophilic properties, or water-sol. or water-insol. properties, and is treated by a radiation source (14), esp. a multi-radiation laser head, or a combination of a wide band light source and a light scanner. The layer (17) is a tetrahydro-pyranyl modified methyl acrylate dil. with a ketone solvent.