Gravure and its gold and silver ink common troubleshooting

Gravure knowledge

1. Gravure gold and silver ink common faults and troubleshooting

Gravure printing gold and silver ink common faults are the following, exclusion methods are listed after each type of fault.

1 stick back, bonding. After printing the gold and silver ink on the plastic film, the back surface is dirty, and when the film is severe, the peeling between the films will not open, or the background image will be glued off. The main reasons for this phenomenon are the slow dryness of the link material, or the nature of the link material in the bottom ink and the gold/silver ink link material; the ambient temperature is too high, the printing speed is too fast, the pressure is too high, and the far-infrared light is insufficient; It is also sometimes the PE resin film itself is tacky. The exclusion method is to change the formula of gold oil, can use the formula of polyamide oil: polyamide resin 40% to 50%, isopropyl alcohol 25% to 27%, xylene 25% to 28%, and add the same amount of Gold powder. At the same time reduce the operating environment temperature, slow down the printing speed, adjust the pressure, strengthen the air volume and far infrared light. If the resin itself is sticky, replace the resin.

2 shedding. The fastness of the ink layer is extremely poor, and gold and silver powder particles can easily fall off. The reason is that using a single solvent to directly harmonize gold and silver powders, lacks the necessary viscosity. Can be solved by changing the link material.

3 burrs, spots. The phenomenon is that a large part of the area produces speckle patterns, and the gloss is extremely poor; some of the ink is spread outward from the edges of the image. The reason is that the printing is too light, the solvent is too much, the leveling property is poor, the pattern is too deep, and the plastic film is electrostatically accumulated. The method of elimination is to control the amount of solvent and apply anti-static treatment to the plastic film, and the pattern should not be too deep when making the plate.

4 escape. Thin lines are not clearly printed or printed. The reason is that the link material dries too fast and the printing speed is too slow. Large areas of gold and silver ink blocks and thin lines coexist in gold. The exclusion method is to adjust butanol, adjust the printing speed, and divide the large-area color and thin lines into two plates.

5 colors gray. Gold and silver inks are dark and dull. The reason for this is that the time of reconciliation is too long. It is oxidized or eroded by acids, alkalis, sulfur and other chemical substances, and is colored with other inks. The method of elimination is that gold ink is used with the adjustment and the ink pump, pipe, ink tank and printing plate are cleaned on time to prevent cross-coloring. Once the color is strung, it is replaced immediately.

6 paste version. Before the gold and silver inks have been transferred to the film surface, they have dried in the printing plate texture. The reason is that the printing plate has not been cleaned in time, so that the residual ink is solidified in the pattern and gradually accumulated, so that patterns, lime sand and the like are incorporated into the ink. The exclusion method is to clean the plate at any time and pay attention to the hygiene of the operating environment.

2. The type of gravure :

Gravure has two major categories: gravure and gravure. Photogravure is further divided into traditional gravure (ie, carbon paper or photogravure) and photographic gravure. The engraving gravure is divided into hand carving, mechanical carving and electronic engraving. Currently used are gravure, photographic gravure and electronic engraving gravure.

1 gravure is on the dichromate sensitized carbon paper, first drying gravure network, and then drying continuously adjusted positive image, and then transfer the carbon paper image onto the roller, through the development, Fill plates and corrodes to make plates.

(2) Photogravure Gravure plate printing method applies direct emulsion coating on roller by spraying method or slip ring method, directly exposing printing plate with positive plate added with concave net, then developing, filling plate, and etching to obtain printing plate. .