A clamping shaft (12) for a rotationally driven part (14) is described. It comprises at least one fluid chamber (28a, 28b) being located inside a shaft body (16) and being delimited by a piston (30a, 30b) and a cylinder part (32a. 32b). Additionally, the fluid chamber (28a, 28b) is delimited by an elastic clamping region (24a, 24b) having a first diameter if the piston (30a, 30b) and the cylinder part (32a, 32b) are in a first relative position, and a second diameter if the piston (30a, 30b) and the cylinder part (32a, 32b) are in a second relative position. Furthermore, a preloading unit (38) is provided, biasing the piston (30a, 30b) and the cylinder part (32a, 32b) towards the second relative position. Moreover, a printing cylinder unit (10) of a printing machine is presented comprising such a clamping shaft (12). Also, a method for operating a clamping shaft (12) is explained.

A can decorator includes a plate cylinder shaft, a plate cylinder structured to be installed on the plate cylinder shaft, and a plate cylinder locking and unlocking mechanism structured to selectively lock the plate cylinder to the plate cylinder shaft such that the plate cylinder shaft and plate cylinder rotate in conjunction and to selectively unlock the plate cylinder from the plate cylinder shaft such that the plate cylinder shaft and plate cylinder do not rotate in conjunction and the plate cylinder is permitted to be removed from the plate cylinder shaft. The plate cylinder locking and unlocking mechanism uses at least one of pneumatic, magnetic, and mechanical power to selectively lock and unlock the plate cylinder.

A method is provided for automatically exchanging a sleeve (18a) of a printing tool (14, 16, 18, 22, 24) mounted in a printing machine (12), in particular a flexographic printing machine, by means of a printing tool handling unit (28) comprising a coupling interface (36). In one step of the method the printing tool handling unit (28) is temporarily coupled to a coupling interface (46) located at the end of a shaft (54, 56, 58, 60) of the printing tool (14, 16, 18, 22, 24) with its coupling interface (36). In a further step, the printing tool handling unit (28) transports the printing tool (14, 16, 18, 22, 24) to a separation unit (78) comprising at least one clamping device (80, 82, 84) and places the printing tool (14, 16, 18, 22, 24) in the clamping device (80) of the separation unit (78). The printing tool (14, 16, 18, 22, 24), in particular a sleeve (18a) of the printing tool (14, 16, 18, 22, 24), is clamped by the clamping device (80), and the printing tool handling unit (28) separates the shaft (54, 56, 58, 60) from the sleeve (18a) by pulling the shaft (54, 56, 58, 60) out of the sleeve (18a) while the sleeve (18a) is clamped in the clamping device (80).

A printing roller for a printing machine, e.g., for a flexographic printing machine, wherein the printing roller includes a rotary and longitudinal axis and an external surface, the external surface being substantially cylindrical and adapted for mounting a plate. The new feature of a printing roller according to the invention is that the external cylindrical surface includes at least one longitudinal groove, where the at least one longitudinal groove includes a geometry with one or more surfaces, the surface or surfaces lying within a circumscribed cylindrical surface for the external surface of the printing roller. In other words, this means that the longitudinal groove or grooves are cutouts in the form of milled or ground grooves in the external cylindrical surface itself on a printing roller.

Method for applying an image built up of multiple ink layers on a face of a container A method for applying an image built up of multiple ink layers on a face of a container, in particular a cup, is provided. In the method. UV curable process colour inks are provided as primary colours of a CMYK colour system, the UV curable process colour inks having different viscosity in substantially non-overlapping viscosity ranges and the UV curable process colour inks are applied to the blanket in an order of decreasing viscosity. Also, several components of a flexographic transfer printing system which are compatible for use with the method are provided.

A method for assembling a hollow cylinder on, or removing a hollow cylinder from, a further cylinder. The hollow cylinder includes a body with openings for creating an air cushion within a first portion of a shell and a second portion of the shell is gas-impervious or has openings for creating an air cushion of a reduced quantity and/or size compared to the first portion. The openings are connected to a gas feed and a gas inlet inside the body. The further cylinder has openings on a shell and gas is fed though the openings via an internal gas supply. An assembly method includes providing the hollow cylinder, applying a seal to the first portion to prevent escape of gas from the first portion, providing the further cylinder, applying gas to the further cylinder so that gas escapes from the openings, and pushing the hollow cylinder onto the further cylinder.

A system for the replacement of sleeves that can be slipped on arbors of ink transfer rollers of at least printing machine has a storage device, in which the sleeves not being, used in current ink transfer can be stored, and a transport device, with which several sleeves can be transported to the printing machine. The system has a transfer device the facilitates the transfer of the sleeves between the storage device and/or the transport device and the arbors of the ink transfer rollers, and/or between the storage device and the transport device.

A system for the replacement of sleeves that can be slipped on arbors of ink transfer rollers of at least printing machine has a storage device, in which the sleeves not being used in current ink transfer can be stored, and a transport device, with which several sleeves can be transported to the printing machine. The system has a transfer device the facilitates the transfer of the sleeves between the storage device and/or the transport device and the arbors of the ink transfer rollers, and/or between the storage device and the transport device,

A plate cylinder enables a printing plate to be attached thereto and is improved in strength. A plate cylinder is attached to a rotationally driven plate driving shaft, and is configured to mount a cylindrical printing plate attached thereon from a tip end side thereof. The plate cylinder is provided with a plate cylinder main body having a plate mounting surface to which the printing plate is attached. A flat portion is formed on a flat surface positioned further toward a radially inner side than the plate mounting surface. A plurality of hole portions is formed side by side in an axially separated state in the flat portion. A plurality of plate fixing members tightly fixes the printing plate to the plate mounting surface. The plate fixing members are fitted into the hole portions, and are provided to be movable in radially inward and outward directions of the plate cylinder.

A sleeve assembly in which a pair of annular end rings are screwed into respective ends of an annular sleeve which includes around its inner surface a compressible liner. Respective surfaces of both end ring and sleeve are provided with specific complementary groove, chamfer, undercut or channel formations, and prior to screwing insertion of an end ring into a sleeve end, respective surfaces and formations are filled and covered with a viscous but fluent curable gasket forming composition such that amounts of gasket forming composition provided on and continuously around the end ring unite with corresponding amounts of gasket forming composition provided within and completely around corresponding surfaces of the sleeve as and when the end ring is completely screwed into a sleeve end. When the respective amounts of gasket forming composition provided on end ring and sleeve unite together and cure, effective rib or band-like rubberized seals are created.