The relationship between knife line and ink particle size

The thickness of the ink particles is closely related to the production of the knife line. The finer the ink, the better the quality of the printed product, resulting in a corresponding reduction in the knife line and the probability. There are strict requirements on the size of the ink's grain size. Usually the ink's fineness is 15um. The ink's fineness will not meet the requirements. The rough particles will push the blade upwards, which will result in the knife line. At the same time, the too coarse ink particles will cause the blade and printing. The damage of the edition is very big, the thickness of the ink should be moderate, too thin and not good.

Plastic gravure knife line causes and solutions

After long-term observation of such knife lines, it was found that the direction of the knife lines caused by the rough ink particles is not the same on the printed products, mainly in three forms.

1. Irregular thickness lines appear on the prints of the first knife line, which extend from the printed pattern part to the unpatterned part. The knife line is longer, and with the squeegee's left and right swings, the knife line also moves, sometimes one, two, and sometimes many. The solution is to adjust the position of the squeegee up and down. At the same time, we should observe whether the color of the squeegee is missing or not.

2. The direction of the second knife line is very regular, appears in the printing pattern part on the same printing plate, and is in the same position, with the squeegee's left and right swing, basically no big change, this is because the ink The coarse particles in the top push up the scraper, and the left and right swing of the scraper cannot drive it at all. If it appears in the middle color, the next color ink will fill the cut lines, that is, the next color ink appears at the cut line.

3. The third knife line is easy to appear in the last color, usually printed on the white plate in the plastic film, such a one or two knife lines will run through the entire print, viewed from the front of the print, if The knife line is not rough, not easy to find, from the back of the printed product can see the knife line through the formation of the "mark", this "trace" will appear undoubtedly in the compound, especially when the composite aluminum film, more It can be clearly seen.

Whether it is the above kind of knife line, the solution is to stop printing, filter the ink, usually the first and second color used in the ink before filtering on the machine, the filter mesh 140 mesh metal screen, after long-term practice It has achieved initial results and is worthy of learning and learning from peers.