摘要:
A method for operating a web printing press is provided. The method includes unwinding a substrate from a roll to define a web; during makeready, printing the web using at least one print unit, the makeready ending when the web is being printed to a desired standard; stopping the web after the makeready; rewinding the web so that the substrate printed during the make ready pass back through the print unit; and unwinding again the rewound substrate to pass through the print unit. A press and printed product are also provided.
摘要:
A method is provided which reduces substrate waste while adjusting the press parameters to obtain a satisfactory image. The method includes the steps of: supplying a web to a printing press; printing a plurality of first images on the web at corresponding printing positions; inspecting one of the first images on the web; rewinding the web to one of the printing positions; and printing a further image over one of the first images on the web. A printing press is also provided which is configured and arranged to print in accordance with the method.
摘要:
In an apparatus for imprinting a material web including a transport arrangement for moving the material web through the apparatus along stations for applying coloring agents to the material web and fixing the coloring agent applied to the web, and a web buffer arranged in the web transport direction of the material web ahead of the first imprinting station for accommodating a section of the material web moved back out of the station area upon shutdown of the apparatus, at least one clamping structure (11a, 11b) is provided for fixing the material web (3) during the movement of the material web back out of the station area.
摘要:
The printing unit has two cooperating cylinders (1, 4) which form the printing nip and which have printing saddles (2, 5) separated by cylinder pits (3, 6). The paper web (7) passing through the printing nip is transported in the pilgrim-step mode, in order to print formats adjoining one another. The two cylinders (1, 4) are angularly adjustable relative to one another, in respect of the position of their printing saddles (2, 5) cooperating in the printing nip, in a manner offset by the amount of a circumferential distance which is approximately equal to the difference between the circumferential length (S) of a printing saddle and the circumferential length (B) of a printing image. The impression zone is therefore only approximately as large as the printing image, and the impression-free zone available for retracting the paper web is correspondingly enlarged.
摘要:
A web guide roller assembly for a printing machine utilizes a cylindrical roller support body and a concentric hollow roller body. An annular space between the support body and the roller body is filled with a pressure medium so that the roller body floats on the support body. Suitable end seals are utilized to prevent escape of the pressure medium.
摘要:
The rotary web-fed printing machine has three successively arranged printing units, namely one offset and two intaglio printing units which are all of a similar design to sheet-fed printing units and in which the cylinders (2, 3) forming the printing nip have a plurality of sectors separated by cylinder pits (2a, 3b). Each printing unit has, in front of the printing nip, a first paper-web store (29) and an intermittently controllable first draw-roller unit (30) and, after the printing nip, an intermittently controllable second draw-roller unit (31) and second paper-web store (32), the draw-roller units (30, 31) which have only one suction roller being controllable for the forward and backward movement of the web (P) by means of individually regulated drives (30a, 31a) and at the same time serving for the register check. In front of the first paper-web store (29) of the first printing unit (A), between the printing units within the portions limited by the respective paper-web stores and behind the second paper-web store of the last printing unit, the web (P) is moved uniformly by continuously driven draw-roller arrangements (27), whereas during the run through the printing nip the paper-web transport takes place in the pilgrim-step mode.
摘要:
A method of printing a succession of images on to an elongate web, in at least two colors, comprises feeding the web past the first and second rotating printing cylinders 10 and 11, the first print cylinder applying a first color and the second print cylinder applying a second color, and periodically interrupting the movement of the web past the print cylinders, the length of the interruptions controlling the repeat distance, and the interruptions of the movement of the web past the second cylinder being controlled in dependence upon the images being produced by the preceding print cylinder. The web may be driven by means of a servo motor such that the extent to which the web moves while the motor accelerates to and/or decelerates from, its normal running speed is accurately predetermined.
摘要:
In printing machines, it is often necessary to move materials at two different speeds, for example, bulk movement from one station to another, and precise movement to effect registration for printing. Disclosed herein is apparatus for transmitting power to a drum from two motors via a single output shaft. The apparatus includes a shaft having a coupling disc at one end which can move axially under the control of an actuator either to engage a flywheel driven by a high speed motor or a drive ring driven by a stepper motor via a gear. The other end of the shaft has a gear which transmits the motor drive to the drum via a gear attached to the drum shaft.
摘要:
An impression cylinder (11) and a blanket cylinder (2) are made in contact with/separated from each other at prescribed timing. Continuous paper (12) inserted between the impression cylinder (11) and the blanket cylinder (2) is intermittently fed in association with the said timing for printing. A pin feed tractor (13) arranged on an inlet side of a printing position forward/reversely feeds and stops the continuous paper (12) at timing previously set in relation to the said timing for contact/separation. A suction conveyer (14) arranged on an outlet side of the printing position sucks and conveys the printed continuous paper (12) while switching its suction force in plural of stages in relation to the said paper feeding timing.
摘要:
A printing device includes a plate carrying cylinder in contact with a printing transfer cylinder two or three times its circumference. Two pressure cylinders are movable between a withdrawn position and a use position where they maintain a web in printing contact with the printing transfer cylinder at two distinct positions, for forming two impressions on the web during one cycle. A method for printing in accordance with the device is also disclosed.