Maschinenfabrik Wifag

Olivier Stehlin

Matthias Riepenhoff

Walter Siegl

A wet offset printing form has atop layer containing a photocatalytically and thermally modifiable material. The material can be brought photocatalytically into a hydrophilic state by irradiation with light and into a lipophilic state by heating. The hydrophilic state forms a surface that can be illustrated and the lipophilic state forms an illustrated surface. The top layer of the wet offset printing form may contain absorption centers for irradiation, especially for laser radiation in the NIR range, with which heating of the top layer in the pattern of an image is brought about.

Wet offset printing form

A wet offset printing form has a top layer containing a photocatalytically and thermally modifiable material. The material can be brought photocatalytically into a hydrophilic state by irradiation with light and into a lipophilic state by heating. The hydrophilic state forms a surface that can be illustrated and the lipophilic state forms an illustrated surface. The top layer of the wet offset printing form may contain absorption centers for irradiation, especially for laser radiation in the NIR range, with which heating of the top layer in the pattern of an image is brought about.

A control device for controlling the tension of a paper web of a printing press is provided with a setting device for a speed master set point, with a speed controller for a drive motor, which is coupled with the setting device, with a setting device for a web tension set point, with a sensor for measuring the web tension, with a web tension controller, which is coupled with the sensor for measuring the web tension and with the setting device for the web tension set point. The speed controller is coupled with an output of the web tension controller. A process is also provided for controlling the tension of a paper web of a printing press, wherein a speed master set point is preset, a web tension set point is preset, a first web tension actual value is measured, the difference between the web tension set point and the measured web tension actual value is formed; the difference formed is converted into a lag set point, and a variable, which is used to control the speed of rotation of the drive motor, is formed from the preset speed master set point and the lag set point.

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Moutier, Switzerland

Olivier Stehlin