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
  • 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
  • B41N3/00—Preparing for use and conserving printing surfaces
  • B41N3/003—Preparing for use and conserving printing surfaces of intaglio formes, e.g. application of a wear-resistant coating, such as chrome, on the already-engraved plate or cylinder; Preparing for reuse, e.g. removing of the Ballard shell; Correction of the engraving

Definitions

• Removable matrix for the cylinders of rotogravure print ⁇ ing machines, for their further use
• the invention concerns the cylinders for rotogravure print ⁇ ing machines .
• rotogravure work a cylindrical form is normally used to print the desired image by means of an engraving process during which tiny hollow cells are formed that receive the ink subsequently transferred onto paper.
• the surface in which said cells are made by various methods - traditional, autotypical, conversion, electronic or some other - is generally of perfectly smooth copper. This surface is obtained by galvanic deposition on steel cylinders and is generally given a chromium plated finish. For each new set of images the cylinders are processed by specialized engravers and then sent to the user who mounts them onto rotogravure printing machines.
• the surfaces of these matrixes are of the same copper as that used for traditional cylinders for good engraving re- suits.
• the best known consists of having a set of holes bored in the mandrel and through these air passes and spreads between the surface of the mandrel and the matrix to allow the latte to be slipped on and its position adjusted. Once this is done the flow of air is cut off so that the matrix and mandrel are held firmly together. To remove the matrix the process is reversed. The old matrix is eliminated and replaced by a new one with different images for a new printing run.
• Running costs for corrections, balancing and maintenance are reduced, as well as those for staff and transport.
• Print quality is better with avoidance of adjusting movement or costly wasted materials.
• the above invention eliminates these drawbacks and offers other considerable advantages both practical and economic as will be explained below.
• Subject of the invention is a process for forming metal ma ⁇ trixes that can be taken off the mandrels of rotogravure printing machines, on which matrixes there, is a film of electrolytic copper for engraving purposes.
• the copper film is applied to the matrix and between one and the other there is a layer acting as a separator.
• the presence of the separator means that the film can be easily taken off when the image it carries is no longer neede A new film for a fresh engraving is then deposited on the matri
• the separator product consists of a solution of silver or of passivating substances such as chromates, bichromates or other
• the separator is preferably an aqueous solution of silver salt whose titre of silver lies between 0.1 and 0.7 grams/litre.
• the base of the matrix is preferably nickel.
• a film of copper is applied to the matrix and then the sepa ⁇ rator product .
• mechanical means are used, after which a new film is applied following application of the separator product.
• the new engraved film is then chromium plated or given ano ⁇ ther protective coating.
• Fig. 1 A mandrel for rotogravure printing carrying a matrix subject of the invention, perspective view.
• Fig. 2 A matrix, as invented, perspective view.
• Fig. 3 The matrix on a mandrel while the engraved film is being removed .
• Fig. 4 The matrix on a mandrel after removal of the engraved film.
• Fig. 5 The matrix after formation of a new film to be en ⁇ graved .
• Fig.1 illustrates a cylinder 10 like that on a rotogravure printing machine.
• Said cylinder 10 comprises a mandrel 11, with pins 12, car ⁇ rying a removable matrix 15, subject of the invention, on which there are engravings 16 for an image to be printed on a run of a certain length.
• On the surface of the mandrel there is a set of holes (not shown in the figure for simplicity) that serve to create an air cushion between the mandrel 11 and the matrix 15 when the latter is being slipped onto said mandrel 11.
• Ha ing onc fitted the matrix on correctly the flow of compressed air is cut off and the matrix 15 will then cling tightly to the sur face of the mandrel 11.
• the matrix 15 is formed of a nickel base 21 over which is laid a film 22 of copper .
• a product 23 is applied consisting of a solution of silver whose function is that of a separa ⁇ tor .
• the user turns on the com ⁇ pressed air in the mandrel 11 and removes the matrix 15 whic can be sent to the engraving department.
• the matrix 15 is slid onto a mandrel 18, with pins 19, similarly provided with means such as air cush ⁇ ions or others, that facilitate this operation and then lock said matrix 15 in place.
• Mechanical means are employed by the engraver to detach the film 24 as may be seen in Fig. 3.
• Fig. 4 illustrates the matrix 15 with its nickel base 21 and the first copper film 22 after removal of the film 24.
• a film 37 of galvanized copper can then be formed after ap plication of the silver solution to create the separator 36.
• Fig. 5 shows the matrix 15 completely renewed with the fresh film 37. Said ustrix can therefore be engraved as desired by the user, after which it is sent to the user for a new printing run .

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Inorganic Chemistry (AREA)
• Printing Plates And Materials Therefor (AREA)
• Manufacture Or Reproduction Of Printing Formes (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=11366300

Family Applications (1)

Country Status (5)

Families Citing this family (3)

Family Cites Families (6)

• 1993
  • 1993-05-31 IT IT93MI001130A patent/IT1264791B1/it active IP Right Grant
  • 1993-07-12 AU AU45827/93A patent/AU4582793A/en not_active Abandoned
  • 1993-07-12 CZ CZ953097A patent/CZ309795A3/cs unknown
  • 1993-07-12 EP EP93916146A patent/EP0701508A1/de not_active Withdrawn
  • 1993-07-12 WO PCT/IT1993/000074 patent/WO1994027831A1/en not_active Ceased

Non-Patent Citations (1)

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