Abstract: An ink supply system (10) comprises an ink chamber (12); an ink line (14) with a Venturi nozzle (16), wherein the ink chamber (12) has an inlet (18), which is connected to the ink line (14) upstream of the Venturi nozzle (16), and an outlet (24), which is connected to the suction side of the Venturi nozzle (16); an ink reservoir (30) from which the ink is transferred by a pump (28) to the inlet (18) and into the ink line (32); and an ink return line (32), which connects the downstream end of the Venturi nozzle (16) with the ink reservoir (30).

Abstract: A method for attaching a printing plate (12), especially a flexographic printing plate, to a printing cylinder (14) is described. In a first step, the printing plate (12) is provided in a substantially flat condition. Thereafter, an outer circumference of the printing cylinder (14) is arranged adjacent to an edge of the printing plate (12). Subsequently, the printing cylinder (14) is translatorily moved over the printing plate (12) while rotating such that the printing plate (12) is rolled-up on the printing cylinder (14). Additionally, an apparatus (10) for attaching a printing plate (12) to a printing cylinder (14) is presented. The apparatus (10) comprises a printing plate support unit (16) having a substantially flat support surface (18) for supporting the printing plate (12) to be mounted on the printing cylinder (14), and a printing cylinder support unit (36) for supporting and moving the printing cylinder (14).

Abstract: A method for the determination of print parameters of a printing machine, particularly a flexographic printing machine, comprises the following steps: First, a print form (12) is provided and mounted on a print cylinder (14). Then, at least one high-resolution image of the surface of the print form (12) is recorded by means of a 3D camera (18). On the basis of the at least one high-resolution image a height profile of the print form (12) is determined and then a simulated print image is calculated on the basis of the height profile and an initial set of print parameters. Finally, optimized print parameters are determined by checking and/or varying the print parameters of the initial set. For this purpose, a simulated print image is calculated again after the print parameters have been varied. In addition, a test stand is specified on which such a method can be carried out.

Abstract: A printing press (10) has at least one electric motor (14), which is arranged at a distance of less than 0.5 m from an emission source (18). At least one explosion protection wall (22) is provided, such that the thread measure (F) between the emission source (18) and the electric motor (14) is greater than 0.5 m.

Abstract: A dryer unit (18) for applying a dryer gas to a sheet material inside a printing machine comprises a dryer body (20) having a first set (26) of dryer gas output openings (28). These openings (28) are arranged in a substantially regular pattern covering an application width (20a) of the dryer unit (18). Additionally, at least one dryer gas output slot (38) is arranged upstream the first set (26) of dryer gas output openings (28). Furthermore, a printing machine is presented which comprises such a dryer unit (18).

Abstract: A bearing assembly (26) is described. It is suitable for supporting a printing cylinder or an anilox roll in a printing machine and comprises at least one roller bearing (28, 30) being configured for receiving a shaft (12b, 14b, 16b) associated with the printing cylinder or the anilox roll. Additionally, it has a first support part (32) carrying the roller bearing (28, 30) and a second support part (34) being a carrier element of the printing machine or being configured for being mounted to a carrier element of the printing machine. Furthermore, a fluid chamber (36) is provided acting between the roller bearing (28, 30) and the second support part (34). Moreover, a printing machine is presented wherein a shaft (12b, 14b, 16b) associated with a printing cylinder or an anilox roll thereof is supported by such a bearing assembly (26).

Abstract: The invention is about a valve system to grip a sleeve over a mandrel in a press, in particular on how the gripper is brought toward and away from the mandrel and sleeve assembly. The gripper is disengaged from the sleeve, following first a straight path and then a helicoidal path, thanks to an ad-hoc slot machined on an axle. This allows to disengage the gripper and set it out of the way for handling the sleeve, with a single motor and a single instruction.

Abstract: A method for the determination of print parameters of a printing machine, particularly a flexographic printing machine, comprises the following steps: First, a print form (12) is provided and mounted on a print cylinder (14). Then, at least one high-resolution image of the surface of the print form (12) is recorded by means of a 3D camera (18). On the basis of the at least one high-resolution image a height profile of the print form (12) is determined and then a simulated print image is calculated on the basis of the height profile and an initial set of print parameters. Finally, optimized print parameters are determined by checking and/or varying the print parameters of the initial set. For this purpose, a simulated print image is calculated again after the print parameters have been varied. In addition, a test stand is specified on which such a method can be carried out.

Abstract: The invention is about a convenient way of fixing a sleeve over a mandrel in a press. The sleeve is attached by applying a hydraulic pressure into the mandrel which deforms itself and grips on the sleeve. The pressure is brought by a piston mounted on a screw inside the mandrel, which when tightened increases the pressure and grips the sleeve.

Abstract: The present invention relates to a dryer for treating a moving printing web in a rotary printing press with gas, having a nozzle body. The dryer according to the invention is characterized in that the nozzle body has at least one opening for the exit of heated gas and has at least one opening for recirculating the cooled gas.

Abstract: A sleeve station dedicated to the assembly of a sleeve and a mandrel for a flexographic press. The sleeve station can be loaded manually, and assembles the sleeve with the mandrel in a vertical orientation when both are in a vertical orientation with aligned axes, avoiding problems caused by the bending of the sleeves during assembly. After loading of the sleeve, it is returned to a horizontal axis orientation.

Abstract: The invention is about a convenient way of fixing a sleeve over a mandrel in a press. The sleeve is attached by applying a hydraulic pressure into the mandrel which deforms itself and grips on the sleeve. The pressure is brought by a piston mounted on a screw inside the mandrel, which when tightened increases the pressure and grips the sleeve.

Abstract: A color proofing apparatus, including an engraved roller (12) having a pattern of ink accommodating cavities on its peripheral surface, a back pressure cylinder (14) forming a nip with the engraved roller (12), a conveyor (16) adapted to feed a sheet (18) of a print substrate through the nip in synchronism with the movements of the peripheral surfaces of the engraved roller (12) and the back pressure cylinder (14), and an optical sensor (30) disposed at the conveyor (16) for measuring a color value of the sheet (18) that has passed through the nip.

Abstract: A colour proofing apparatus, including an engraved roller (12) having a pattern of ink accommodating cavities on its peripheral surface, a back pressure cylinder (14) forming a nip with the engraved roller (12), a conveyor (16) adapted to feed a sheet (18) of a print substrate through the nip in synchronism with the movements of the peripheral surfaces of the engraved roller (12) and the back pressure cylinder (14), and an optical sensor (30) disposed at the conveyor (16) for measuring a colour value of the sheet (18) that has passed through the nip.

Abstract: A method of adjusting a roller (18) in a rotary printing press (10), includes the steps of a) mounting the roller (18) in a preparation rack (24) so as to be rotatably supported therein, b) scanning the peripheral surface of the roller, thereby to detect a topography of the roller surface, c) deriving set data for the adjustment of the roller from the topography, and storing the set data, d) mounting the roller in the printing press (10), and e) adjusting the roller in accordance with the set data.

Abstract: A printing press includes at least one exchangeable cylinder (10, 12) that is rotatably supported in a machine frame, a movable bearing member (18) forming part of a bearing (44) for the exchangeable cylinder (12), and a sensor head (26, 28, 30) that is capable of receiving signals from a signalling device (22, 24, 32) that is mounted on one of the cylinders (10, 12) of the printing press, and the sensor head (26, 28, 30) is mounted on the movable bearing member (18) and is arranged to receive the signals from a signalling device (22, 24, 32) at least when the bearing member (18) is in a predetermined position.