A screen-printing cylinder includes a cylinder shell and one or more flexible surface elements on the cylinder shell. The one or more flexible surface elements are at least one of resilient or springy, and the one or more flexible surface elements are elliptical patches or circular patches. The flexible surface elements give way upon contact with sheet grippers projecting from an impression cylinder, so that it is not necessary to move the screen-printing cylinder out to avoid contact with the sheet grippers.

A squeegee device for a printing press, which prints a printing material, at at least one printing point, in accordance with a screen printing process, comprises a screen printing screen, a squeegee which is one of set against the screen printing screen in a thrown-on position and can be set against the screen printing screen In a thrown-on position, a bearing device which makes a throwing-on and throwing-off movement possible between the thrown-on position of the squeegee and a thrown-off position, and a drive device, by the use of which, the squeegee can be set against the screen printing screen and can be set away from the latter during operation in a manner which is correlated to a press or printing material phase position. The drive device is set up to one of bring about and to make possible throwing-on and throwing-off of the squeegee in sequences which differ from one another in one of different positions and the phase lengths in relation to the length of the screen printing screen.

A rotary screen printing press is provided with a screen-cylinder throw-on/off motor encoder (231) that detects the position of a screen cylinder (201), a squeegee throw-on/off motor encoder (232) that detects the position of a squeegee (221), and a control unit (300) that controls screen cylinder throw-on/off motors (209) and squeegee throw-on/off motors (224) based on the position of the screen cylinder (201) detected by the screen-cylinder throw-on/off motor encoder (231) and the position of the squeegee (221) detected by the squeegee throw-on/off motor encoder (232) so that the squeegee (221) may not contact a screen plate (201A) except when the screen plate (201A) is in contact with an impression cylinder (100).

A sheet-processing machine includes a turning device. Sheets can be conveyed, by a sheet conveyor system, from a sheet guide cylinder in the turning device, and can be conveyed in a sheet conveyor direction on a sheet conveyor path. A sheet guide element is provided beneath or along the sheet conveyor path. A deionization device is assigned to the sheet guide element. The deionization device can provide positive and negative ions.

Screen printing device for applying an ink, having at least: a) a conveyor belt, b) a rotating hollow cylindrical screen stencil arranged above the conveyor belt with a circumferential screen and a rotating ink removal cylinder arranged adjacent the screen stencil, wherein: c) inside the screen stencil an ink supply device, a first doctor blade adjacent the conveyor belt, a second doctor blade adjacent the ink removal cylinder, and a third doctor blade, which is arranged upstream of the first doctor blade in the running direction of the conveyor belt and/or the rotational direction of the screen stencil are provided.

A sheet-processing machine includes a turning device. Sheets can be conveyed, by a sheet conveyor system, from a sheet guide cylinder in the turning device, and can be conveyed in a sheet conveyor direction on a sheet conveyor path. A sheet guide element is provided beneath or along the sheet conveyor path. A deionization device is assigned to the sheet guide element. The deionization device can provide positive and negative ions.

A sheet-fed simultaneous printing machine has two directly interacting collecting cylinders with respective axes of rotation. An axial plane contains these axes of rotation. A reference plane contains such an axis of rotation of this type and has a horizontal surface normal. The intersection angle between the axial plane and the reference plane is max 0.5°. The sheet-fed simultaneous sheet printing unit has exactly four plate cylinders, of which two are arranged such that they directly interact with the first and two are arranged to such that they directly interact with the second collector cylinder. An inking unit with a respective ink supply is arranged in each plate cylinder and a supply sectional plane is determined for each ink supply, which intersects this ink supply and which also contains the axis of rotation of the corresponding plate cylinder. An intersection angle between the reference plane and a supply sectional plane of the respective ink supply is max 35°. A sheet-fed machine comprises at least one sheet-fed printing unit of this type, as well as a sheet-fed printing unit having two directly interacting impression cylinders. An intersection angle between the axial plane on one side and the reference plane on the other side is max 45°.

There is described a printing press adapted to carry out printing on a sheet-like or web-like substrate, in particular for the production of security documents such as banknotes, comprising a substrate feeding device for feeding the substrate to be treated, at least a printing unit designed to print a first side and/or a second side of the substrate and a delivery unit for receiving the treated substrate. The printing press in the conveying path for the substrate between the feeding device and the delivery unit further comprises an in-line casting device adapted to apply a layer of material acting as an optical medium on a portion of the second side of the substrate and to replicate and form a micro-optical structure in the layer of material acting as optical medium, wherein the printing unit comprises a first printing group comprising a printing cylinder and being adapted to print at least one printed pattern on the first or second side of the substrate in register with the micro-optical structure.

In some examples, a screen printing unit includes a screen printing forme cylinder, an impression cylinder, and at least one further rotational transport body. A fixing element of the impression cylinder includes inner and outer contact surfaces for clamping sheets. The inner contact surface has a base radius as a distance from an axis of rotation of the impression cylinder. A cylinder barrel of the impression cylinder has a supporting surface for sheets that includes an impression portion having a constant barrel radius, which extends over at least 170° about the axis of rotation of the impression cylinder and the barrel radius is larger than the base radius. A fixing element of the further rotational transport body includes an inner and an outer contact surface for clamping sheets. The inner contact surface includes the base radius as a distance from an axis of rotation of the further rotational transport body.

A printing system for rotary screen printing includes a screen-printing cylinder having flexible surface elements. The flexible surface elements give way upon contact with sheet grippers projecting from an impression cylinder, so that it is not necessary to move the screen-printing cylinder out to avoid contact with the sheet grippers. A screen-printing cylinder, a method for producing a screen-printing cylinder, a printing machine and a method for using a screen-printing cylinder, are also provided.