The determinants of cut line generation

The production of the knife line is related to the thickness of the ink particles. The finer the ink, the better the quality of the print and the corresponding cut lines and odds. At the same time, if the particles are finer, the hiding power is better. There are strict requirements on the grain size of the ink. Generally, the fineness of the ink is required to be 15 and the fineness of the ink cannot meet the requirements. The rough particles will push up the scraper. Produce knife line, at the same time the too coarse ink particle to the blade, the printing plate damage is very big, the ink thickness must be moderate, too thin is not good. 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:

The first type of knife-line prints have irregular thickness lines on the prints. The line extends from the printed pattern part to the non-patterned part. The knife line is long. As the doctor blade swings left and right, the knife Lines are also moving, sometimes one, and sometimes many. The solution is to adjust the position of the squeegee up and down, and at the same time observe whether the color of the squeegee is missing or not. Especially when the printing plate is a shallow web, the squeegee can be easily adjusted from top to bottom.

The direction of the second knife line is very regular and appears in the same position on the printing pattern part on the same printing plate. With the squeegee left and right, basically no major changes. This is because the coarse particles in the ink lift 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 these cutting lines. That is, the next color of ink hue appears at the knife line.

The third kind of knife line is easy to appear in the last color, usually printed on the white plate when printing in the plastic film, such one or two knife lines will penetrate the entire print product. When viewed from the front of the printed product, if the knife line is not rough, it is not easy to find out. From the back of the printed product, you can find the trajectory of the knife line, and always form a long mark. This kind of trace will appear undoubtedly during compounding, especially In the composite aluminized film, it is more legible in a large area of ​​white.