Factors Affecting Printing and Coating Quality of Aluminum Foil

When the gravure printing foil is used, if the ink concentration is too low, the printed text pattern will not be bright and the gravure printing will occur. If the ink density is too high, cracks will appear at the pattern, which will not only waste ink, but also cause prints. The surface is uneven and not beautiful.

At present, most pharmaceutical aluminum foil printing and coating equipment employs an anilox roller coating device, which is also called a wire coating method. The anilox roller is composed of a hole and a net wall. The pit on the roller is usually called a net hole, and the high part is called a net wall or a network cable. The ratio of the net wall to the net hole is about 1:5. After the anilox roller is processed, a hard chrome with a thickness of 0.015 to 0.02 mm is plated to increase the surface hardness of the anilox roller. The hardness value is HRC62. ~65.

When using the aluminum foil device for printing and coating, the construction principle and working state of the anilox roller are as follows: when the binder is filled in the anilox roller, the anilox roller rotates, and when the cell dot leaves the adhesive liquid surface, The liquid on the smooth surface of the roller is scraped off by a scraper, leaving only the liquid that cannot be scraped off in the concave groove. The liquid adhesive is then brought into contact with the surface of the coated aluminum foil substrate. This contact is made through a resilient rubber. By the action of the pressure roller, a part of the adhesive solution in the cell site is transferred to the surface of the aluminum foil substrate. Since the adhesive has fluidity, it will automatically level out on the surface of the aluminum foil to make the original liquid become continuous. Even liquid layer.

A part of the liquid in the anilox roller net room is transferred to the aluminum foil, and the anilox roller is rotated at the same time, and then it is immersed again in the binder liquid after one rotation, the liquid binder fills the net hole, and the cycle starts again. , An anilox roller with a small diameter can transfer the adhesive solution to the aluminum foil substrate uniformly without interruption, so that the surface of the aluminum foil can achieve the purpose of uniformly coating the mixture agent.

If the screen wire in the anilox roller is smaller per inch and the cell site is shallow, the filled adhesive volume is small, and the coating amount thereof is relatively small. The anilox roller has a different shape of the cells, and its coating amount is not equal. 200 pyramidal anilox rollers have 200 cells per inch, and there are about 8 cells per mm. The storage capacity of the binder is About 0.5 pounds per 1000 square feet, or 2.4 grams per square meter, and 24 triangular-threaded anilox rolls, the binder stocks up to 13 pounds per 1,000 square feet, or 63 grams per square meter.