DE828625C - Process for the production of printing plates for offset printing - Google Patents

Description

Process for the production of printing plates for offset printing Im Offset printing uses printing plates made of zinc, aluminum etc. as well as bimetal plates, z. B. made of steel and copper, copper and chrome, which have the different behavior of metals versus fat. The manufacture of such panels is carried out by Folding, and with the bimetal process, the second metal layer is applied by electroplating.

The invention assumes that these rolled metal webs many times are not available. On the other hand, however, the offset printing companies own usually galvanic equipment from the gravure printing process. The invention shows the way how such companies make their electroplating systems far more economical can take advantage of and develop by self-production of deliveries of such rolled products Can make offset plates independently.

The invention consists in that on a roller of appropriate dimensions after a separating layer has been applied, a correspondingly strong metal precipitate as Coat .galvanisch is generated, which after reaching the required strength for Obtaining a tensionable pressure plate cut in the longitudinal direction, from the roller is detached at the separating layer and trimmed to size. on Printing plates produced in this way by electroplating have proven themselves in practical use well proven. In this way, you are also able to produce bimetal plates yourself, especially those where the actual base plate itself is already out two different metals is made to e.g. B. more valuable To save non-ferrous metal, read only for the surface layer of the base plate is used.

For example, on a copper jacket made in this way, you can: Electroplating a thin layer of chrome so that the plate for the Bimetal process is ready. It is advisable to apply the @base plate layer before application to grind and polish another metal layer.

The metal spraying process can also be used instead of the galvanic process use. Subjected to treatment to which such plates are subjected to to make them printable. In this process, you can make the base layer from one less valuable metal and only their offset-related surface made of copper which is then followed by the chrome layer.

Claims (2)

PATENT CLAIMS: Embodiment If you want z. B. to produce a printing plate, the roller used is one whose diameter is selected according to the required web length. Because this roller can rotate in the bath or opposite the metal spray nozzle, differences in the thickness of the precipitation layer are avoided. Once the layer has reached the desired thickness, the surface is ground, polished and, for the bimetal process, galvanically coated with another metal layer, chrome or the like. Now it is cut lengthways, detached from the circumference of the roller at the separating layer and finally the other r. A process for the production of printing plates for offset printing, characterized in that, after applying a separating layer, a correspondingly strong metal deposit is formed as a b'lantel galvanically or by metal spraying on a metal rotating roller of corresponding dimensions, then cut open in the longitudinal direction to obtain a tensionable printing plate and on the Separating layer is detached from the base roll. 2. Procedure according to claim r, characterized in that the metallic jacket thus formed at least in its top layer made of the offset-related metal, z. B. copper, is then ground, polished and now on its surface is covered with a galvanic thin layer of other metal, such as chromium.