Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N1/00—Printing plates or foils; Materials therefor
  • B41N1/16—Curved printing plates, especially cylinders
  • B41N1/20—Curved printing plates, especially cylinders made of metal or similar inorganic compounds, e.g. plasma coated ceramics, carbides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C1/00—Forme preparation
  • B41C1/02—Engraving; Heads therefor
  • B41C1/04—Engraving; Heads therefor using heads controlled by an electric information signal
  • B41C1/05—Heat-generating engraving heads, e.g. laser beam, electron beam
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N1/00—Printing plates or foils; Materials therefor
  • B41N1/04—Printing plates or foils; Materials therefor metallic
  • B41N1/06—Printing plates or foils; Materials therefor metallic for relief printing or intaglio printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N1/00—Printing plates or foils; Materials therefor
  • B41N1/04—Printing plates or foils; Materials therefor metallic
  • B41N1/08—Printing plates or foils; Materials therefor metallic for lithographic printing
  • B41N1/10—Printing plates or foils; Materials therefor metallic for lithographic printing multiple

Definitions

• the invention relates to a method for producing a Printing form for gravure printing, especially for Rotogravure, with the cell in the surface the printing form are formed, a printing form for the Rotogravure, especially for rotogravure, and the use of such a printing form in a Printing device.
• Printing forms for gravure printing, also printing cylinders or Engraving cylinders are mainly used in engraving devices by means of a recording organ in the form a mechanical engraving device or by means of a Electron or laser beam or etching produced.
• a template to be reproduced is provided with a scanning organ scanned point by point and line by line to obtain an image signal to gain what the tonal values of the scanned original represents.
• the image signal is made according to the requirements reproduction, for example after a predetermined gradation curve, corrected and a raster signal overlaid to generate the print screen.
• the through the superimposition of image signal and raster signal formed recording signal controls the recording element, which is in the axial direction on the rotating Printing cylinder moved along and a sequence of im Depressions or recesses arranged in the printing grid, Called well, in the outer surface of the printing cylinder engraved. Scanning the template that the previous one Principle follows, is usually done nowadays only with electronic scanning of the template.
• the image data supplied by the scanning are recorded on a Given computer, in which a program-based processing and processing is done. In many cases no more templates are scanned these days, because photographs are often already digital Data in front of and texts and graphics can be saved on the computer also generated in the form of digital data become.
• the computer then delivers the image signals based on which the cups either mechanically or by means of Direct laser engraving or a laser mask process formed in the outer surface of the printing cylinder were.
• the depths or volumes of the engraved cells determine the tonal values to be printed between "black” and "white” in the printing terminology too labeled "depth” and "light”.
• the engraved impression cylinder is used for the printing process then clamped in a rotogravure press.
• each cell takes one of its own Volume dependent amount of ink on the tonal value to be printed corresponds.
• the color transfer from the wells to the Media is done.
• a gravure cylinder that is used in practice generally from a cylinder core made up of Steel, aluminum or more recently also from a plastic composite can exist and which also with a Base layer, for example made of copper, is provided.
• a Base layer for example made of copper
• the wells are engraved. Copper exhibits due to its physical and chemical Characteristics good engraving characteristics on which to support the generation of high-quality prints.
• the Thickness of the electroplated copper engraving surface is approx. 60 ⁇ m to 140 ⁇ m.
• the layer and the underlying, the engraved copper layer from the Printing form removed chemically, electrochemically or mechanically.
• the printing cylinder stands for a new one Cycle to produce another printing form Available.
• the disadvantages were the low process reliability and the not enough good representation of halftones for Pictures.
• the etching process has also been modified by for the mask layer on the one hand a so-called photoresist and on the other hand, a so-called thermoresist was chosen.
• both Cases were masked by a laser beam exposed (one also says illustrated).
• the laser beam creates a photoresist Conversion of the irradiated areas of the resist layer, being before etching to produce the finished mask another development step is necessary.
• the laser beam generates the thermal resist Mask in one step by passing the laser through thermal processing removes the mask layer there, where a cell should be created by etching. Both procedures are complex, in the sense that they are relatively many Show process steps. You are therefore in practice susceptible to quality problems. Beyond they also the fundamental disadvantage of all Etching process, namely the halftones for pictures are poorly represented.
• the zinc layer must also after the imaging (laser engraving) with a wear-resistant layer, for example made of chrome to be sufficient in the printing press To achieve service life.
• a wear-resistant layer for example made of chrome to be sufficient in the printing press.
• the problem is that the application of chromium to zinc is also less reliable works as chrome plating on copper, so the combination of a zinc with a chrome plating is complicated. Therefore, there is a need for more Introduce procedural steps. In addition to the difficult Handling zinc makes disposal especially in combination with chrome is another problem.
• the object is achieved according to the method according to the invention in that the surface with a wear-resistant Layer is provided.
• Copper has a Vickers hardness in the range from 40 kp / mm 2 (soft) to in the range from 110 kp / mm 2 (hard).
• Chrome has a Vickers hardness in the range from 120 kp / mm 2 (soft) to 670 kp / mm 2 (hard) - information from "Stoffdazzling", 4th edition, 1978, p. 1102, 1103.
• basically all materials that have a greater Vickers hardness than copper, that is to say greater than 110 kp / mm 2 are advantageously possible for the formation of this layer.
• the actual engraving layer is copper on the Printing form, which is regularly designed as a so-called printing cylinder is. So far, the copper layer is, as at the beginning described to the service life of the printing form during increase their intended use, Chrome applied. So there were two shifts so far to apply to the printing form, for which two separate galvanic baths must be provided and therefore two separate galvanic coating processes must be carried out.
• the printing form there is basically only one layer the printing form to apply what the manufacturing process the printing form as a whole in terms of time and in relation to the Manufacturing costs significantly reduced.
• certain wear-resistant layers not necessarily galvanic be applied, which also has the advantage that after the end of the intended period of use the printing form the wear-resistant layer often with simpler measures from the printing form can be removed again as before.
• a wear-resistant layer depending the desired goal especially with regard to the desired application of such a printing form can be selected, i.e. the hardness of the wear-resistant Layer with regard to the available for this standing material which is the wear-resistant layer forms, can be selected or adapted. This selection can also from the point of view of later removal the wear-resistant layer from the printing form, after the printing form after the intended Period of use removed from the printing form and the associated disposal criteria.
• the method is designed such that the wear-resistant layer on the printing form before training the well is formed.
• the wear-resistant layer is the real one Engraving surface or layer of Printing form forms.
• This can advantageously be achieved will be that after completing the training of the wells, i.e. after completion of the engraving or illustration of the Printing form directly into the wear-resistant layer without further time-consuming preparatory steps.
• the quasi-finished printing form into the printing device Execution of the printing process can be introduced. Only the removal of material residues that arise in the course of the engraving or illustration, or that Deburring and, if necessary, a subsequent grinding, polishing or cleaning process may be required.
• This proposed advantageous further modification of the solution becomes the manufacturing process of the printing form in terms of time and also in relation to the expenditure involved Significantly reduced costs.
• the wear-resistant layer can advantageously be a be a so-called hard material layer, for example such a layer, as used for surface coating of metal-cutting Tools such as drills, milling heads and turning tools are used to increase their service life.
• metal-cutting Tools such as drills, milling heads and turning tools are used to increase their service life.
• everyone in the prior art is suitable for this Known hard material used for purposes, for example boron carbide and its derivatives in order to only use this material here, for example. to call.
• the wear-resistant layer can also advantageously be formed by a composite material the example of a mixture of plastic and therein contained particulate elements.
• the particulate Elements can preferably be quartz sand his.
• the wear-resistant layer can also be made from a metallic layer are formed, the metallic Layer formed on the one hand from elemental metal and on the other hand also from metal alloys, the choice of whether the layer is now made of a metallic Material, a hard material or a composite material trained in the sense of the above is, depending on the desired with the printing form or properties to be guaranteed in relation also on the type of printing with the printing form, the to achieve the desired service life, the later required Removal of the wear-resistant layer and the type performing the engraving of the printing form or the wear-resistant one Layer of the printing form can be selected.
• the wear-resistant layers can go through regularly the coating methods known per se, such as preferably CVD or PVD (Chemical Vapor Deposition, physical vapor deposition) be using these techniques on a larger scale are technically proven and manageable.
• CVD chemical Vapor Deposition
• PVD Physical Vapor Deposition, physical vapor deposition
• Hard material layers and metallic layers can be in this way, using these known methods, with high precision in terms of coating uniformity and the desired thickness of the coating on one Apply the surface, here the printing form.
• the composite materials mentioned can be, for example, by means of a spraying process on the surface of the printing form Apply to form the wear-resistant layer and are then thermal and / or through Irradiation hardened by electrons.
• the thickness of the layer can preferably be chosen in this way be what ultimately all types of layer composition and the application of the layers applies that the wells at least partially in the wear-resistant Layer are formed.
• the wear-resistant layer on a previously conventional layer applied to the printing form For example, made of metal such as copper or zinc, or on one non-metallic layer is applied and only the area close to the surface due to the wear-resistant Layer is formed and the well in the area of Well bottom in the under the wear-resistant layer lying layer are formed, but it is also possible to under the thickness of the wear-resistant layer No separate layer under the wear-resistant Layer, preferably the well to be completely formed in the wear-resistant layer.
• the wear-resistant layer is accordingly advantageous in the range between 20 to 50 ⁇ m thick be trained, using the known CVD and PVD process Layer thicknesses in the range of up to 10 ⁇ m are easy to manufacture and beyond down to the range of 15 ⁇ m, i.e. that also by means of of these known PVD or CVD coating processes such wear-resistant layers on printing forms can be produced in which the wells are even complete be trained without the underlying Layers, if any, are touched by the cells become.
• the wells formed therein can layer basically in any suitable known manner be trained, for example, by a wide variety of them known methods, for example by means of a mechanical Engraving means or an engraving by means of laser light. These different engraving processes too depending on the wear-resistant layer forming material can be selected.
• a mechanical engraving means is, for example, an engraving stylus from a suitably shaped diamond.
• An engraving process using laser light can advantageously be chosen such that by means of the laser light the cells are formed directly, i.e. high-energy laser light forms the well in the wear-resistant layer in relation to its three-dimensional Shape (length, width, depth) directly from.
• the wear-resistant layer can happen also advantageously form the cells by etching, previously before performing the etching process Photoresist or a thermoresist to form the etching mask is formed on the wear-resistant layer.
• Photoresist or a thermoresist to form the etching mask is formed on the wear-resistant layer.
• etching engraving techniques as they do previously with copper impression cylinders, in which the cells have been trained, have been and are being used, can in principle also be related here according to the invention with the etching of the wear-resistant layer be applied. This also applies to another advantageous development of the invention, namely the etching mask itself is exposed by means of laser light.
• This degree of roughness preferably corresponds to one So-called.
• Micro roughness which is preferably by polishing and / or grinding the surface becomes.
• a printing form for rotogravure especially for rotogravure, in which cups are formed on the surface of the printing form are wear-resistant on the surface Layer on in which the wells are related to their depth are at least partially formed.
• the printing form listed above can preferably according to the method according to one or more of the method steps, as described in detail above have been manufactured. But it is also possible fundamentally different manufacturing process steps to use the printing form according to the invention.
• Printing form or after the production of the Printing form according to the inventive method can Printing form in a printing device, in particular in a Rotary printing machine, be inserted to the to be printed Print the material as intended.
• a Printing form for gravure printing is essentially cylindrical trained printing form, which regularly consists of a steel core consists, but basically also of other materials, For example, plastic.
• a base copper layer can be formed, using known application techniques on the steel core is applied.
• Base layers can be applied to the steel core, e.g. a basic zinc layer.
• a wear-resistant layer is then applied.
• the wear-resistant layer can have a thickness have that a subsequent illustration of the Printing form, i.e. the training of the wells in which Layer takes place without the underlying metallic Base layer is acted upon by the cells or the cells in this underlying base layer penetration.
• wear-resistant layer under no wear layer is formed in the wear-resistant layer must become. Rather, it is also possible that wear-resistant layer directly on the core element of the Printing form, whether made of steel or other materials, train.
• the printing form is illustrated in a manner known per se, which, depending on the choice, by means of different Engraving techniques can be done.
• the illustrated printing form i.e. with the wear-resistant layer of the engravings Surface treatment by polishing and / or grinding subjected. Polishing and / or grinding can be done in this way take place that a predetermined roughness or microroughness the surface is reached.
• the polishing and / or grinding is used to remove unwanted ones Residues of the wear-resistant layer that during the engraving process or the imaging. This also removes burrs.
• a separate one Cleaning process after polishing and / or grinding can join. These editing steps can also during engraving or imaging done in one step. Depending on the Material of the wear-resistant layer results in certain materials no need at all, after imaging, a grinding, polishing or cleaning step perform.
• the printing form is fundamentally qualified for the intended use in a printing device or rotary printing press to be used and the printing process as intended of material to be printed, which means known printing processes takes place.
• the imaging contained wear-resistant layer of removed the printing form so that the printing form, in particular the printing cylinder, for a new manufacturing cycle the printing form is available, which in principle can be done multiple times.
• the removal of the wear-resistant Layer can be by chemical, electrochemical or mechanical way, depending on the type of wear-resistant Layer.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Ceramic Engineering (AREA)
• Inorganic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Plasma & Fusion (AREA)
• Manufacturing & Machinery (AREA)
• Manufacture Or Reproduction Of Printing Formes (AREA)
• Printing Plates And Materials Therefor (AREA)

Priority Applications (1)

Applications Claiming Priority (4)

Publications (1)

Family

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Family Applications (2)

Family Applications Before (1)

Country Status (6)

Cited By (1)

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Citations (8)

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• 2003
  • 2003-08-02 EP EP03017492A patent/EP1410923B1/fr not_active Expired - Lifetime
  • 2003-08-02 DE DE50304555T patent/DE50304555D1/de not_active Expired - Fee Related
  • 2003-08-26 JP JP2003301643A patent/JP2004136660A/ja active Pending
  • 2003-09-02 CN CNA031557880A patent/CN1491794A/zh active Pending
  • 2003-09-10 EP EP03020399A patent/EP1410924A1/fr not_active Withdrawn
  • 2003-09-22 US US10/667,822 patent/US20040129152A1/en not_active Abandoned
  • 2003-09-23 CA CA002442247A patent/CA2442247A1/fr not_active Abandoned
  • 2003-10-07 US US10/680,514 patent/US6877423B2/en not_active Expired - Lifetime

Patent Citations (8)

Non-Patent Citations (1)

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