US 2006/0185538 A1 · Method and apparatus for printing a web

Abstract

In a method and an apparatus for printing on material in web form print images are successively applied to the web by a transfer cylinder. The web is continuously drawn into the printing station and the speed at which the web is moved in the printing station during a printing operation is greater than the speed at which it is drawn into the printing station. After the printing operation the web is positioned in the printing station for the following printing operation relative to the transfer cylinder which is not in contact with the web during a part of a revolution of 360.degree., and at the same time the path of the web is altered in accordance with the change in the speed thereof. The web is driven by the impression cylinder which is associated with the transfer cylinder and around the peripheral surface of which the web partially passes. Positioning of the web for the respectively following printing operation is implemented by a change in the rotary movement of the impression cylinder.

Claims20

Dependent claims

An apparatus for printing a web comprising:

at least one printing station comprising an impression cylinder having a peripheral surface around which the web partially passes for driving the web and a transfer cylinder for successively applying print images to the web in the at least one printing station, the transfer cylinder being out of contact with the web during a part of a complete revolution of 360°;
a driver for rotatably driving the impression cylinder,
a controller for controlling the driver of the impression cylinder to position the web relative to the transfer cylinder for a respectively following printing operation, and
a first compensation device in the at least one printing station for changing the direction of the web, the first compensation device being arranged reciprocatably in the direction of travel of the web upstream of the impression cylinder in dependence on the rotary movement of the impression cylinder, whereby the web forms at least a first loop which is variable in respect of its length in dependence on the movement of the first compensation device.

1 more element

Dependencies are inferred from the claim text.

Method and apparatus for printing a web

Life of this patent

Method and apparatus for printing a web

Life of this patent

Abstract

Claims20