A printing unit has a printing forme cylinder. A plate changer is arranged in a manner which is allocated to the printing forme cylinder. The plate changer has a bearing surface on which a printing forme, which is arranged or is to be arranged on the printing forme cylinder, can be laid. That bearing surface is arranged such that it can be moved to and fro between at least two defined positions longitudinally with respect to the rotational axis of the printing forme cylinder. The printing forme is arranged and registered on the bearing surface of the plate changer. At least two edges of a carrier for the relevant printing forme, which are arranged at a right angle with respect to each other, are brought into physical contact with register pins which are arranged on the bearing surface of the plate changer. A first edge of the carrier of the relevant printing forme is arranged to bear against a first register pin and a second edge, orthogonal with respect to the first edge, of the carrier of the relevant printing forme, is arranged to bear against a second register pin. The printing unit is preferably arranged as a device for printing hollow bodies.

A printing machine has a printing tower with a plurality of printing units arranged one above the other and a printing form changeover system having at least one vertically movable storage device for printing forms. A first machine plane, which is associated with one or a plurality of first printing units, is provided. A conveying system, which can move the vertically movable storage device from a loading position located in the region of the first machine plane to an advanced position which is vertically spaced apart, is provided. In addition to the vertically movable storage device, an additional storage device which is associated with the first printing unit of the printing tower is provided.

A printing machine has a printing tower with a plurality of printing units arranged one above the other and a printing form changeover system having at least one vertically movable storage device for printing forms. A first machine plane, which is associated with one or a plurality of first printing units, is provided. A storage is associated with the printing tower. The storage can be moved between a removal position located in the region of the first machine plane and a loading position which is vertically spaced apart therefrom by a conveyor system. The loading position is associated with the second printing unit of the printing tower with a view to feeding printing forms. During the changeover of the printing forms, received printing forms are transported by the vertically movable storage.

An apparatus is comprised of a plurality of printing units for printing hollow elements. A conveying device conveys the hollow elements to be printed into a printing zone of at least one of the printing units. At least one of the printing units includes a plate cylinder to which a plate replacing mechanism is assigned.

A plate processing line and methods for producing a flexographic printing plate. An imaging station applies image information to a first plate. A first exposure station cures the first plate. One or more of water, a solvent, and/or a thermal process is further applied to the first plate. A drying station or an after-exposure station is configured to expose the plate to further radiation. A feeding station is configured to feed the first plate cured by the exposure station and a second plate cured by a second exposure station to the processing station. A transportation cart may transport the plate between the first or second exposure stations and the processing station.