Gravure printing units and method for adjusting and/or modifying an ink transfer in a gravure printing method

Patent metadata

Field	Value
Publication number	US-11559976-B2
Application number	US-202017413606-A
Country	US
Kind code	B2
Filing date	Feb 3, 2020
Priority date	Feb 5, 2019
Publication date	Jan 24, 2023
Grant date	Jan 24, 2023

Abstract

A gravure printing unit, which is usable for printing on a substrate, according to a gravure printing method, includes a forme cylinder which comprises, on its circumference, an image-forming pattern of recesses, and an inking unit, by the use of which the pattern of recesses provided on the forme cylinder is inked. The forme cylinder can be partially inked from an inking device via a first inking unit cylinder which has recesses in the region of its outer cylindrical surface that correspond to recesses on the forme cylinder, and via a second inking unit cylinder, which cooperates with the first inking unit cylinder and which comprises ink-transferring elements or raised areas on its circumference. For controlling the transfer of ink, the first inking unit cylinder having the recesses, is configured as being temperature controllable or has a temperature control device in the ink unit supply. Alternatively, a printing pressure between inking units cylinders can be varied during operation. The invention also relates to a method for adjusting or modifying a transfer of ink and for operating the gravure printing unit.

First claim

The invention claimed is:

1. A gravure printing unit for printing onto substrate in a gravure printing process, the gravure printing unit comprising:
a forme cylinder, which forme cylinder comprises, on a circumference of the forme cylinder, an image-forming pattern of individual forme cylinder recesses;
an inking unit, by the use of which inking unit the pattern of the individual recesses provided on the forme cylinder is inked;
an inking device in the inking unit, wherein the pattern of the individual recesses provided on the forme cylinder can be inked from the inking device via a first inking unit cylinder, which has first inking unit cylinder recesses in a region of an outer cylindrical surface of the first inking unit cylinder and that correspond to individual ones of the individual forme cylinder recesses on the forme cylinder;
a second inking unit cylinder, which second inking unit cylinder contacts the first inking unit cylinder and which comprises ones of ink-transferring elevations and raised areas on a circumference of the second inking unit cylinder;
wherein the inking device comprises, on at least a downstream side of an ink application point, in an operating direction of rotation of the first inking unit cylinder having the first inking unit cylinder recesses, a retaining means configured as one of an ink blade and as a doctor blade, which retaining means, in an operating position, is in physical contact with an outer cylindrical surface of the first inking unit cylinder, and by the use of which retaining means, printing ink applied previously to the outer cylindrical surface of the first inking unit cylinder is removed, downstream of the ink application point and upstream of a first nip point between the first inking unit cylinder and the second inking unit cylinder, as viewed in the operating direction of rotation;
wherein the first inking unit cylinder having the first inking unit cylinder recesses is configured as temperature controllable, wherein control means are provided, via which control means a temperature of the first inking unit cylinder can be varied in a targeted manner during operation of the gravure printing unit; and
a drive means, the drive means being actuated by a controller, for modifying a transfer of ink during operation of the gravure printing unit, by which drive means a variation of a printing pressure can be brought about in at least one of (i) the first nip point between the first inking unit cylinder and the second inking unit cylinder, or (ii) a second nip point between the second inking unit cylinder and another cylinder that contacts the second linking unit cylinder, wherein the other cylinder that contacts the second linking unit cylinder, wherein the other cylinder that contacts the second inking unit cylinder is one of the forme cylinder or a third inking unit cylinder, and
wherein, during the variation of the printing pressure, physical contact is maintained between at least the first inking unit cylinder and the second inking unit cylinder.

2. The gravure printing unit according to claim 1 , wherein a temperature control fluid can flow through the first inking unit cylinder having the first inking unit cylinder recesses and wherein the first inking unit cylinder is line-connected to a unit that supplies the temperature control fluid, at least one of at a temperature and at a volumetric flow rate of which temperature control fluid is variable, which temperature control fluid can be supplied via the unit that supplies the temperature control fluid for controlling ink transfer.

3. The gravure printing unit according to claim 1 , wherein an ink distribution device having at least one ink distributor is provided, which at least one ink distributor can be moved back and forth in an axial direction of the first inking unit cylinder by an ink distributor drive and which one of comprises an end that protrudes into an ink supply chamber of the inking device, at least in a working position, and comprises an ink outlet of a line system provided for feeding in ink, which line system leads into the ink supply chamber.

4. The gravure printing unit according to claim 1 , wherein the second inking unit cylinder and the forme cylinder form the second nip point, and the first inking unit cylinder, the second inking unit cylinder, and the forme cylinder are mounted in a frame of the gravure printing unit such that an axial distance of the first inking unit cylinder, the second inking unit cylinder, and the forme cylinder from an adjacent one of the first inking unit cylinder, the second inking unit cylinder, and the forme cylinder can be varied during operation, while physical contact between the first inking unit cylinder and the second inking unit cylinder, and physical contact between the second inking unit cylinder and the forme cylinder is maintained, and wherein the position of one of the first inking unit cylinder and the second inking unit cylinder and the forme cylinder itself relative to the other inking unit cylinders or the forme cylinder or a stop means that limits a thrown-on position thereof can be adjusted by use of the drive means, which can be actuated remotely via the controller.

5. The gravure printing unit according to claim 1 , one of wherein the inking device is configured without inking zones, and wherein one of the retaining means and an ink supply unit that supports the retaining means and that is mounted axially movably in the inking device can be one of moved and oscillated axially during operation in terms of its axial position relative to the first inking unit cylinder that comprises the first inking unit cylinder recesses, by an inking device drive means.

6. The gravure printing unit according to claim 1 , wherein a positioning drive comprising a remotely actuable positioning drive means is provided, by means of which positioning drive, one of the doctor blade, an ink supply unit comprising the doctor blade and at least parts that delimit an ink supply chamber and the entire inking device can one of be set against and moved away from an outer cylindrical surface of the first inking unit cylinder and can be varied in terms of a force with which it is set against the outer circumferential surface of the first inking unit cylinder, and which repositions one of the doctor blade, the ink supply unit and the entire inking device when an operative end of the doctor blade becomes shortened due to wear.

7. The gravure printing unit according to claim 1 , one of wherein the inking device is mounted, coupled to the first inking unit cylinder having the first inking unit cylinder recesses, one of in and on a frame in such a way that when the first inking unit cylinder is moved radially, the inking device is moved along with the first inking unit cylinder while maintaining a radial relative position between the first inking unit cylinder and a retaining means, and wherein the first inking unit cylinder having the first inking unit cylinder recesses is mounted one of in and on the frame such that it can be removed for one of replacement and for maintenance and for make ready purposes.

8. The gravure printing unit according to claim 1 , wherein:
the second nip point is between the second inking unit cylinder and the third inking unit cylinder,
the third inking unit cylinder is downstream of the second inking unit cylinder, and
during the variation of the printing pressure, physical contact is maintained between the first inking unit cylinder and the second inking unit cylinder, and between the second inking unit cylinder and the third inking unit cylinder.

9. A method for one of adjusting and modifying a transfer of ink in a printing unit operating according to a gravure printing process including:

Assignees

• Koenig & Bauer Ag

Inventors

• Chassot Daniel
• Sokol Ralf

Classifications

• B41F9/021

  Sheet printing presses · CPC title

• B41F13/11

  Gravure cylinders {(attaching cylindrical formes B41F27/105)} · CPC title

• B41F9/063 Primary

  Using inking rollers · CPC title

• B41F31/002

  Heating or cooling of ink or ink rollers · CPC title

• B41P2231/00

  Inking devices; Recovering printing ink · CPC title