Gravure plate printing principle

First, engraving method

1. Hand-engraved gravure

The hand-engraved gravure is carved on the copperplate with various guillotines. It can directly etch the concave lines. It can also be coated with a resist film on the copperplate to scratch the resist film and expose the surface of the copperplate. Chemically etched.

2. Mechanical engraving gravure

Mechanical engraving gravure is the use of color pattern engraving machine, embossing engraving machine, parallel line stencil machine and scale engraving machine and other mechanical direct engraving, or scratch the copper surface of the corrosion layer and then re-etched into gravure.

Hand-engraved or mechanically-engraved gravure lines are exquisitely detailed, and patterns are delicately printed. They are mainly used to print banknotes and bonds with security values.

3. Electronic engraving

(1) Electronic film engraving

1 film production.

2 roller installation.

3 film paste.

4 programming.

5 test moments.

6 scan calibration.

7 engraving.

(2) No film electronic engraving

The working principle of filmless electronic engraving is: the original is scanned into the computer, the use of computer to complete the revision, typesetting, imposition and other work, after soft proofing or color digital proofing, the final generation of electric engraving machine color image file, and then directly send The electric engraving machine controlled engraving system for engraving.

1 front input.

2 plate layout work station.

3 proofing.

Compared with traditional gravure platemaking process

A. Improve product quality. No color separation films are used to reduce information loss and improve the quality of engraving.

B. Improve platemaking efficiency. Efforts have been made to eliminate manual work such as photocopying, clipping, dipping, and developing, and the cycle of platemaking has been greatly shortened.

C. Reduce costs and expenses. Films, development, processing, photography and other materials are no longer needed

D. Reduced equipment investment.

E. Improved design and production capabilities.

4. Laser engraving

The gravure laser engraving uses one or more high-energy laser beams to ablate the mesh holes on the material to be carved on the surface of the drum.
Gravure laser engraving method:

(1) Directly engrave the metal surface of the roller with a high-energy laser to form a cyberspace

(2) Apply a coating layer on the copper roller, and use a laser to ablate the area of ​​the cell so that the copper layer at the cell site is exposed. The non-cell hole is protected by the coating layer and resist corrosion. Cyberspace

(3) The surface of the drum is corroded into a desired grid shape, the surface is sprayed with an epoxy resin, and then processed on the surface of the drum and laser-engraved

5. Electron beam engraving

Using a device consisting of an electron beam gun and an electron beam generator and an electron beam optical system, a high-energy electron beam shot directly by an electron beam gun forms a cell site on the copper layer on the surface of the roller.

Electron beam engraving features:

1 Compared with electronic engraving, the production efficiency is 1 to 2 times higher.

2 The electron beam can engrave any line and network line angle;

3 The shape of the grid generated by electron beam engraving is hemispherical, which is favorable for the transfer of ink under high-speed printing.

Second, corrosion gravure plate making method

1. Photogravure method

Also known as the shadow edition, the exposure of the film to the sensitized carbon paper, the surface of the platen roller, and the intaglio plate is developed and etched.

(1) Carbon paper sensitization; (2) printing; (3) overprinting; (4) developing; (5) applying an etching inhibitor; (6) etching; (7) chrome plating.

Mature technology, rich layers of print, fine arts effect. However, the process is complex, the quality is not easy to control, the production cycle is long, the production speed is slow, and the corrosion results of the printing plate are difficult to grasp and predict. The application range is gradually reduced due to the application of the electronic engraving intaglio.

2. Roller imaging gravure production method

Roller imaging gravure production method directly on the photosensitive resist is coated on a degreased copper drum, dried and then printing, development, fill plate, and then etching with ferric chloride etching solution, the drum surface gravure network.

(1) Roller surface treatment

(2) Photosensitive adhesive coating

(3) printing plate

(4) Development and Cleaning

(5) Coating inhibitor

(6) Corrosion