JPH02187335A - Method and apparatus for manufacturing interglio printing plate - Google Patents

Abstract

PURPOSE: To form an intaglio printing plate for accepting different ink amounts in cells of different sizes and depths by forming an intaglio printing intermediate plate having a cell base pattern, and introducing a solid plate making substance liquefied by a printing element delivering unit by an energy action to cells in amounts inversely proportional to an ink amount desired to be transferred. CONSTITUTION: A cell base pattern is provided as an intaglio printing intermediate plate on a surface of a printing plate cylinder 1. The pattern has cells 7 and a web 8 provided between the cells. When a plate making substance liquefied in an amount inversely proportional to image information is injected to one of the cells 7 from a nozzle of a printing element delivering unit 2, the substance is brought into contact with a cold surface of a printing plate cylinder to be rapidly cured to form a layer 9 for reducing a depth of the cell at a bottom of the cell 7. In an inking step to be conducted continued to the image forming step, the cells are filled only with the ink amounts corresponding to a volume of the cell on the intermediate plate obtained by subtracting a volume of each layer 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The invention relates to the production of intaglio printing plates which receive different amounts of ink in cells of different size and/or depth for inking before the printing process. The present invention relates to a method and an apparatus for doing so.

[Prior Art] In conventional intaglio printing plate cylinders, the surface formed by the recesses (cells) and the web remaining between these recesses is removed by mechanical, electrical, electrothermal or chemical material removal. produced (partially through photo-optical and chemical assisted methods).

Since these cells have different sizes, depths or different mutual distances to receive different amounts of ink,
This method is extremely complex in terms of the required tool control or in terms of the number of working steps. The heavy plate cylinders of large machines, weighing up to several tons, are removed from the printing press to produce new printing plates (-negative images), imaged with bulky equipment, and subsequently reinserted into the printing press. There must be. For all these reasons, the intaglio printing process, which produces expensive results from a printing technology point of view, has hitherto been used for economic reasons only in the case of extremely high circulation numbers.

[Problem to be Solved by the Invention] It is an object of the present invention to develop a method and a device for producing intaglio printing plates, which make it possible to produce intaglio printing plates extremely economically.

[Means for Solving the Problem] In order to solve this problem, the method of the present invention includes: a) an intaglio printing intermediate having a cell basic pattern designed at least according to the amount of ink to be transferred to a maximum; The plate was manufactured, and a solid plate-making substance which could be liquefied in the dot transfer unit by the action of energy was introduced into each of the cells in an amount inversely proportional to the amount of ink desired to be transferred.

Furthermore, in order to solve the above problem, the device according to the invention is configured such that a pixel transfer unit is provided, which pixel transfer unit is connected to an electronic image memory via a signal conductor and which stores image information. comprises one or more elements capable of supplying energy according to the
A plate-making substance for forming a negative image on an intaglio printing intermediate plate as a function of the energy application time and/or the energy application intensity from a transfer sheet coated with a meltable plate-making substance and guided by the same element. and further provided with an intaglio printing intermediate plate, the intaglio printing intermediate plate being unimaged, forming a single pattern whose size, depth and/or spacing follow a defined function. It has cells which are filled in various ways with portions of the plate-making material which are introduced in liquid or powder form and harden to form a unique intaglio printing plate.

[Effect of the invention] Using the method according to the invention and the apparatus according to the invention,
Image formation on an intaglio printing plate can be performed directly on a printing press. Therefore, a plate cylinder transport device is completely unnecessary. Intaglio printing plates produced according to the invention can be simply erased on a printing press and prepared for new imaging.

Advantageous embodiments of the method according to the invention are provided in claims 2 to 7.
Advantageous developments of the device according to the invention are described in claims 8 to 13, respectively.

[Examples] Hereinafter, a plurality of embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 designates a printing plate cylinder of an intaglio web rotary printing press. A dot transfer unit 2 is accessible to this printing plate cylinder, which in this case has a guide strip 3 arranged parallel to the outer wall line of the printing plate cylinder and It has a print rad 4 that is movable along the print head. print head 4
is equipped with at least one nozzle through which a solid plate-making substance which can be liquefied under the action of heat is ejected. The temporal and quantitative jetting course is controlled in a similar manner to the inkjet principle of an ink beam printer by a control unit 5 which, via a signal line 6, receives a digital image corresponding to the printed image from an image memory (not shown). Read encoded data. The transfer of the plate-making material is carried out point-wise, line-by-line, using a plurality of nozzles offset in the circumferential direction of the printing plate cylinder l.
Multiple lines can be written in parallel. The information depth, which corresponds to the range of variation in the quantity of plate-making material delivered, is in particular 1 byte per dot, i.e. 256 possible ink gradations on the surface of the printing plate cylinder l. A basic cell pattern (see FIG. 4) is provided as a plate, and this basic cell pattern is formed from cells and webs 8 provided between these cells. The depth of the self is selected to accommodate at least the maximum amount of ink desired to be transferred.

By the way, when a nozzle of the dot transfer unit 2 injects a liquefied plate-making substance in an amount inversely proportional to the image information onto one of the self-plates, this plate-making substance comes into contact with the cold surface of the printing plate cylinder. and cures very quickly to form a cell depth reducing layer 9 at the bottom of the cell (see Figure 5).
During the inking process that follows this image forming process, each cell is filled with only an amount of ink corresponding to the volume of the cell in the intermediate plate for intaglio printing, minus the volume of layer 9. Inking takes place in a known manner using a height-adjustable inking groove 10, into which a portion of the printing form cylinder 1 is immersed in a raised position. Excess ink is scraped off by a doctor 11 that can be applied to the printing plate cylinder 1 and supported by the web 8, and the ink is removed!
It will be returned in 10. The printing image is transferred from the cells to the printing plate web 12 depending on the degree of ink filling of the cells, the printing web being guided partially around the impression cylinder 13 by means of which the printing plate cylinder 1 be forced to.

In a further embodiment shown in FIG. 2, the imaging on the printing form cylinder l takes place indirectly. For this purpose, a transfer belt 15 is arranged between the dot transfer unit 14 and the printing plate cylinder l. The image point delivery unit 14 is connected to the transfer belt 1
a thermal print head 17 with a guide strip 16 arranged transversely to the guide strip 16 and at least one heatable element movable along the guide strip; with this thermal print head and a transfer belt 15; and a transfer sheet 18 disposed between. The transfer sheet 18 is coated on its underside facing the transfer belt 15 with a solid plate-making substance that can be melted under the action of heat. The transfer sheet 18 is wound around a drum 19, and when the transfer belt 15 is further moved by one row for each row, it is further conveyed synchronously with respect to this transfer belt, in which case the transfer sheet is The used portion is wound onto the drum 20.

The heating elements of the thermal printhead 17 melt and deliver different amounts of prepress material onto the transfer belt 15 depending on digitally encoded image information read from an image memory (not shown) by the control unit 21 . It will be done. The transfer of the plate-making material is carried out point-wise, line by line; in this case, by using a plurality of heating elements offset in the circumferential direction of the transfer belt 15, a plurality of lines can be written in parallel.

The information depth, which corresponds to the range of variation in the amount of printing material delivered, is in particular 1 byte per dot, ie 256 possible ink shades. This depth of information is achieved by varying the heating and crimping intensities of the heating elements.

The transfer belt 15 is guided alongside the printing form cylinder 1 via a plurality of deflection rollers 22, with the transfer belt coming into contact with a portion of the surface of the printing form cylinder. An image transfer unit 23 is arranged in this area, and this image transfer unit applies energy to the back side of the transfer belt 15 to melt the plate-making material again and transfer it to the printing plate cylinder l. The image transfer unit 23 is advantageously formed by a roller 24 which can be applied to the back side of the transfer belt 15 with adjustable pressure and which can be heated. Transfer belt 1
The transfer of the plate-making material from the printing plate cylinder 5 to the printing form cylinder I takes place line-by-line, or rather surface-wise, and is therefore significantly faster than the point-wise transfer by the thermal print head to the transfer belt. The separation between the slow writing on the transfer belt 15 and the extremely rapid transfer of the plate-making material stored on said transfer belt to the printing plate cylinder 1 brings significant time advantages to production. That is, after the completion of the printing form, the transfer belt 15 can be removed from the printing form cylinder 1 during printing and already applied with a plate-making substance for the next desired printed image. On a corresponding length of the transfer belt, all printed images required for shift production or one-day production can also be transferred at this location and thus intermediately stored.

3 to 6, parts of the surface of the printing plate cylinder I are shown enlarged at several stages of production of the printing plate. The transfer belt 15, as shown in FIG. 3, is made of two layers: a longitudinally extremely tensile and absolutely dimensionally stable support layer 25, and a rigidly bonded support layer 25, preferably of polytetrafluoroethylene (PTFE). The anti-adhesion layer 26 is made up of an anti-adhesion layer 26. The plate-making material portions 27a27b, 27c, 27d, . In FIG. 4, the transfer belt 15 is pressed onto the surface of the printing plate cylinder 1 by means of a roller 24 with its underside having plate-making material portions 27a, 27b, 27c, 27d-, in which case the plate-making material portions are By applying energy to the back side of 15, it is melted,
They are pressed into the cell basic pattern, where these parts of the plate-making material come into contact with a cold surface and rapidly harden (5th
figure).

Any residual portions of the plate-making material which may protrude beyond the cells can be scraped off in an intermediate step (not shown) by means of a hot doctor, which is applied with light pressure to the web 8. When the finished intaglio printing plate is subsequently inked using the ink groove lO and the doctor 11 (see FIG. 6), each cell is divided into the volume left by the cooled plate-making material 9 of the initial cell volume. It receives only an amount of ink corresponding to 35.

Various possibilities exist for the formation of the transfer belt 15: the transfer belt can be arranged in an exchangeable cassette 28 (see FIG. 7), which cassette is arranged far from the printing plate cylinder 1. The plate-making substance 27, which is imaged by the dot transfer unit 14 and subsequently applied to the printing plate cylinder l, which adheres to the surface of this cassette, is integrated into the cassette or is attached thereto. It is transferred to the printing plate cylinder by an accessible image transfer unit 23.

The transfer belt 15, together with the dot transfer unit 14 and the image transfer unit 23, may be designed in the form of a recombinant robot 29 (see FIG. 8), which is movable along the printing press on a rail system 30. It is placed,
At the end with the image transfer unit 23, different printing plate cylinders l can be accessed alternately. The transfer bell l-15 is guided in this case via a plurality of deflection rollers 31, which are mounted on levers that can be pivoted sideways, thereby ensuring a high mobility of the recombinant robot 29.

Also, other combinations of side-folding members as shown in the various embodiments are also conceivable. Thus, the formation of images on the transfer belt 15 (as a cassette or a recombinant robot) can likewise be carried out by the dot transfer unit 2 of the first embodiment, which operates on the principle of an ink beam printer. Similarly, various variations of the image transfer unit 23 are possible. That is, the transfer belt 15
The heating of the plate-making material part handed over to the
For example, a separate heating device (second
(see figure). The transfer of the plate-making material can be assisted magnetically or electrostatically if the plate-making material is doped accordingly (see magnet 33 in FIG. 7c).

For example, thermoplastics or waxes can be used as plate-making substances for image formation.

With the method according to the invention and the device according to the invention, intaglio printing plates can be produced again very quickly after the end of the printing process for further imaging processes. For this purpose, after washing off the ink residue, an erasing device 34 is brought close to the printing plate cylinder l, as shown in FIG. 9, and this erasing device liquefies the thermoplastic platemaking material using a heat source. It is removed from the printing plate cylinder l using a wiping device and/or a blowing or suction device. To remove the molten printing material, it is also possible to use strips of fleece material, which draw the liquefied printing material into the fiber interstices by capillary forces.

The printing plate cylinder l is advantageously manufactured from a ceramic material. Due to their high abrasion resistance and high thermal stability, such printing plate cylinders have a long service life even with frequent changes of printed images. At the same time, the wear of the doctor sliding on the ceramic web is also reduced.

[Brief explanation of the drawing]

FIG. 1 shows an intaglio printing press with a dot transfer unit brought directly close to the intaglio printing plate cylinder, and FIG. 2 shows an intaglio printing press with a transfer belt for transferring the plate-making material. Figures 3, 4, 5 and 6 illustrate the four different stages of image formation on an intaglio printing plate using a transfer belt, Figures 7a and 7.
Figures b and 7c show a modified embodiment in which the transfer belt is configured as an exchangeable cassette, and Figure 8 shows a modified embodiment in which the transfer belt, dot transfer unit, and image transfer unit are combined into a recombinant robot. FIG. 9 shows an intaglio printing press with an erasing device for printed images.

Claims (1)

[Claims] 1. A method for manufacturing an intaglio printing plate in which cells of different sizes and/or depths receive different amounts of ink during ink application before the printing process, comprising: a) at least maximum transfer; An intermediate plate (1) for intaglio printing with a cell basic pattern designed according to the desired amount of ink is produced; (b) a dot transfer unit (2,
In 14), a solid plate-making substance (27) that can be liquefied is introduced into each of the cells (7) in an amount inversely to the amount of ink to be transferred. how to. 2. The method according to claim 1, wherein the plate-making material inked on the transfer sheet (18) is transferred to the intermediate plate for intaglio printing by a thermal transfer method. 3. Process according to claim 1, characterized in that the plate-making material is sprayed in a fused jet method by means of a device (4) similar to an ink beam printer. 4. The plate-making material is first delivered to the transfer belt (15) in an amount that is inversely proportional to the ink intensity of the individual dots, and from the transfer belt the plate-making material is converted into an intaglio plate by a new energy action. 4. The method as claimed in claim 1, wherein the printing plate is transferred to a printing plate. 5. The method according to claim 4, wherein the transfer speed for transferring the plate-making material from the transfer belt (15) to the intaglio printing plate is higher than that for transferring the plate-making material to the transfer belt (15). 6. Any one of claims 1 to 5, wherein, as another method step, after the plate-making substance has been applied to the intaglio printing plate, the plate-making substance is scraped off using a heatable doctor. Method described. 7. Move the pixel transfer unit (2, 14) to the guide strip (
3, 16) and each cell (7) with an information depth of 1 byte per row by said pixel delivery unit.
7. The plate-making material (27) is transferred indirectly via the transfer belt (15) or directly to the intaglio printing intermediate plate (1) on the basis of individual addressing of the intaglio printing intermediate plate (1). The method described in section. 8. In an apparatus for producing intaglio printing plates which receive different amounts of ink in cells of different size and/or depth during inking before the printing process, a dot transfer unit (2, 14) is provided. the pixel delivery unit is connected to the electronic image memory via signal conductors and includes one or more elements capable of being supplied with energy in response to image information, the elements being meltable; A transfer sheet (1
A plate-making substance for forming a negative image on the intermediate plate for intaglio printing (1) is eluted from 8) according to the energy action time and/or the energy action intensity, and further the intermediate plate for intaglio printing (1) is provided with a single pattern of cells (with size, depth and/or spacing according to a defined function) in the unimaged state of the intaglio printing intermediate plate;
7), and the cell is filled with the plate-making material part (27) introduced in a liquid or powder state and hardened to form a unique intaglio printing plate. A device for manufacturing intaglio printing plates. 9. A pixel transfer unit (14) is arranged in a recombinant robot (29) together with a transfer belt (15) and an image transfer unit (23) which can be rotated by a plurality of link mechanisms, and the recombinant robot performs printing. 9. The device according to claim 8, wherein the device is movable along the machine and alternately accessible to different intaglio printing plate cylinders 1 at the end holding the image transfer unit (23). 10. Claim 8, wherein the transfer belt (15) to which the part of plate-making material (27) separated from the dot transfer unit is transferred is arranged in an exchangeable cassette (28).
The device described. 11. The device according to claim 10, wherein the cassette (28) is connectable with an image transfer unit (23). 12. An image transfer unit is integrated into the cassette (28), and the image transfer unit is attached to the intaglio printing plate (1) on which the image is to be formed each time.
Claim 1: Connectable to an energy source when the device is worn.
The device described in 0. 13. The device as claimed in claim 8, wherein the intermediate intaglio printing form is constructed as a seamless intaglio printing cylinder with a ceramic surface. 14. In the method of erasing an intaglio printing plate produced by the method according to claim 1, after cleaning the ink residue, internal heating or external heating of the intaglio printing intermediate plate (1),
A method for erasing intaglio printing plates, characterized in that the plate-making substance is liquefied or sublimated and the plate-making substance is removed by an erasing device (34) configured as a wiping device and/or a blowing device or a suction device. .