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
  • B41N1/22—Curved printing plates, especially cylinders made of other substances

Definitions

• the invention relates to an intaglio printing cylinder in which a steel cylinder is coated with a coating bearing the print image to be engraved.
• a grating remains in the area of the engraving, which has the height of the cylinder radius and, after inking before printing, serves as a guide for the ink knife (squeegee).
• the ink adhering in the wells of different depths in the printed image is applied to the material to be printed under high pressure.
• Gravure cylinders with copper coatings usually have a service life of around 300,000 to 400,000 prints. Longer service lives of up to 3 million prints can be achieved by applying a thin hard chrome layer of approx. 3 ⁇ m on the engraved copper layer, which however has to be produced by galvanic means.
• the object of the present invention is to provide a gravure cylinder, the coating of which significantly exceeds the number of 400,000 prints without the application of an additional wear protection layer.
• the coating of the rotogravure cylinder consists of polyamide 11 with a melt viscosity of 1.3 to 1.6 or with a melt index of 15/17 g / 10 min. Such a coating leads to a service life of at least 430,000 prints.
• the service life can be increased to approximately 500,000 prints.
• a pigment e.g. Find titanium dioxide.
• cylinders produced in this way can be used for current printed products without further surface finishing, i.e. if no corrections are required after engraving and the print run remains within the aforementioned limits.
• the polyamide 11 coating can contain 20 to 40% by weight of fine-grained, metallically conductive particles, preferably copper particles, and an approximately 3 ⁇ m thick hard chrome layer is electrodeposited on the coating.
• Such an intaglio cylinder is used for demanding, high quality, large print runs.
• the polyamide 11 coating is covered with a layer of a metallic hard material, preferably chromium, chromium-aluminum or tungsten nitride, which is up to 3 ⁇ m thick after engraving. As a result, downtimes of several million prints are achieved.
• a metallic hard material preferably chromium, chromium-aluminum or tungsten nitride
• This process is also particularly environmentally friendly because, in contrast to galvanic coating processes, no acids or other chemicals are required and may need to be disposed of.
• the vortex sintering process is used to produce the polyamide 11 coating, in which powdered polyamide 11 with a grain size of 80 to 250 ⁇ m is placed in a liquid-like state in a corresponding container and the steel cylinder preheated to 230 to 350 ° C is inserted into the polyamide 11 powder-air mixture is immersed.
• the length of the immersion time and the level of the preheating temperature determine the layer thickness of the polyamide 11 coating.
• a PVD method for example cathode sputtering, has proven to be particularly suitable for applying the layer consisting of metallic hard material to the polyamide 11 coating.
• a steel cylinder intended for gravure printing is preheated to a temperature of 250 ° C. and then immersed in the polyamide 11 powder-air mixture in the container of a vortex sintering system for 2 minutes.
• the steel cylinder then has a polyamide 11 coating of approx. 2 mm layer thickness, which after machining the surface is provided with the printed image by electronically controlled engraving.
• the gravure cylinder coated according to the first exemplary embodiment is coated with a chromium nitride layer with a thickness of 2 to 3 ⁇ m after machining its surface and engraving by using the PVD method in about 60 minutes.

Landscapes

• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Printing Plates And Materials Therefor (AREA)
• Manufacture Or Reproduction Of Printing Formes (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=6466618

Family Applications (1)

Country Status (2)

Cited By (3)

Citations (6)

• 1992
  • 1992-08-27 DE DE19924228596 patent/DE4228596A1/de not_active Withdrawn
• 1993
  • 1993-08-06 EP EP93202326A patent/EP0584857A3/de not_active Withdrawn

Patent Citations (6)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events