A device for processing substrates improves processing quality during separation or punching of such substrates. The device has a first processing cylinder and a second processing cylinder for treating substrates, and between which the substrate can be inserted. The substrate undergoes processing as it passes through the cylinder nip between the processing cylinders by use of tool parts that are active therein, and which may be chosen from a group composed of cutting tools, punching tools, creasing tools, perforating tools and grooving tools. The first processing cylinder has a sheet holding system and one of the first processing cylinder and the second processing cylinder has a tool carrier for receiving a tool part. An impression cylinder, which is in surface contact with the second processing cylinder, is assigned to the second processing cylinder, on the side thereof that faces away from the first processing cylinder.

The present invention relates to a device for treating substrates which device is modular and versatile in use. The device for treating substrates comprises a feeder and one or more first sub-structure modules which each comprise a pressure cylinder with devices for fixing a lift and a sheet-conveying device and one or more second sub-structure modules which respectively have a transport cylinder with openings formed on the cover surface thereof, and having devices for fixing a lift and a sheet conveying device. All of the first or second sub-structure modules have the same intersection point for connecting the sub-structure modules on one of the inlet and the exit side and they all can be equipped with an attachment module.

In some examples, a sheet-fed printing unit is configured as a screen printing unit and includes at least one screen printing forme cylinder and at least one impression cylinder cooperating therewith. A cylinder barrel of the impression cylinder includes a supporting surface for sheets, and which includes at least one impression portion having a constant barrel radius that extends over an angle of at least 170 degrees about the axis of rotation of the impression cylinder. The screen printing forme cylinder has an effective screen radius that is smaller than a barrel radius of the impression cylinder, and the effective screen radius is larger than half the barrel radius.

A method of adjusting a machine (1) for printing plate elements (12) equipped with at least one rotary impression cylinder (27) includes the steps of measuring a speed of the element (12, 13) passing through the machine (1), generating an operating signal (34) as a function of the measured speed and a tangential speed of the cylinder (27), and adjusting an operating speed of the machine (1) as a function of the signal generated so that the operating speed of the machine (1) is such that the speed of the element (12, 13) is substantially equal to the tangential speed of the cylinder (27).

A sheet-transport drum includes at least two sheet-supporting surfaces with suction openings. Each respective sheet-supporting surface is formed of first and second comb segments with segment teeth. Suction grooves are provided in the segment teeth and a trailing-edge suction groove is provided in the sheet-supporting surface of each respective second comb segment. A rotary valve is provided for a timed supply of suction air. A plurality of vacuum sources is provided and a trailing-edge suction groove is assigned to each respective vacuum source by the rotary valve. This ensures that the vacuum provided by a respective trailing-edge suction groove at the trailing edge of a respective sheet is reliably maintained even if a previous or following sheet is missing. A sheet-fed printing machine with the sheet-transport drum is also provided.

Examples include a printing unit having a first tool-dependent printing nip formed by a pair of cooperating rotational bodies. The printing unit includes, along a transport path, downstream from the first tool-dependent printing nip, a first alignment cylinder and a first non-impact printing position to which at least one first print head is assigned. The printing unit further includes, along the transport path, downstream from the first non-impact printing position, a first curing device having a first curing area assigned thereto. The printing unit, downstream from the at least one first alignment cylinder, including at least one second alignment cylinder and a second non-impact printing position, to which a second print head is assigned. The printing unit, downstream from the second non-impact printing position, comprising a second curing device having a second curing area assigned thereto.

Examples include a printing unit having a first tool-dependent printing nip formed by a pair of cooperating rotational bodies. The printing unit includes, along a transport path, downstream from the first tool-dependent printing nip, a first alignment cylinder and a first non-impact printing position to which at least one first print head is assigned. The printing unit further includes, along the transport path, downstream from the first non-impact printing position, a first curing device having a first curing area assigned thereto. The printing unit, downstream from the at least one first alignment cylinder, including at least one second alignment cylinder and a second non-impact printing position, to which a second print head is assigned. The printing unit, downstream from the second non-impact printing position, comprising a second curing device having a second curing area assigned thereto.

Examples include a printing unit, which has at least one first tool-dependent printing nip formed by a pair of cooperating rotational bodies. The printing unit includes, downstream from the first tool-dependent printing nip, along a transport path provided for a transport of substrate, at least one first alignment cylinder and at least one first non-impact printing position, to which at least one first print head is assigned. The printing unit further includes, downstream from the first non-impact printing position, along the transport path provided for the transport of substrate, at least one first curing device having a first curing area assigned thereto. Additionally, in the region of the first non-impact printing position, the transport path provided for the transport of substrate is defined by the first alignment cylinder or a rotational transport body arranged directly upstream from the first alignment cylinder.

According to the present invention a sheet handling apparatus is provided which comprises a rotary drum with openings at its peripheral wall. A strip with perforations formed therein spirals circumferentially over an outer surface of the drum in a circumferential spiralling direction, such that a screen is formed over the drum. A suction system controls a flow of air through the perforations thereby to attract sheets towards the drum. The strip is biased by means of a tensioning assembly, which exerts a tensioning force on the strip substantially parallel to the circumferential spiralling direction of the strip.