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What's wrong with the ink in the aluminum foil bag not being cleaned?

Release time:

2021-12-08

Aluminum foil bags are bags made of various plastic films by bag making machines. They are used for packaging food, medical and industrial products, daily necessities, etc. However, aluminum foil bag manufacturers will encounter the problem that the ink on the aluminum foil bags is not clean during production. , So what is the reason why the ink on the aluminum foil bag is not cleaned? The editor will introduce it in detail below.

What's wrong with the ink in the aluminum foil bag not being cleaned?

1. Solvent drying is too fast or too slow.

If the solvent dries too fast, it will not only increase the viscosity of the ink in a short time, but also cause the ink to stick to the free part of the plate cylinder, if the solvent evaporates too quickly, the ink attached to the plate cylinder will be gelatinous . When the plate cylinder passes through the squeegee, due to the high adhesion of neutral ink, the squeegee cannot scrape it off after the plate cylinder runs for a week, and it will be brought directly to the printing substrate, causing dirt and scratches.

The solvent itself volatilizes slowly, causing the free part of the ink on the plate cylinder to not dry on the surface of the plate cylinder in time, and its state is similar to the dotted ink, so when the substrate passes through the plate cylinder, the free part of the ink on the plate cylinder Easily transferred to substrates, causing dirty scratches.

2. The scraper assembly is too soft and the angle is too flat.

The scraper assembly is too soft. When the angle is too low, due to the action of air pressure, the scraper will bend on the surface of the plate cylinder, that is, at the scraper point, causing the relationship between the scraper and the surface to replace the point, so that the ink on the free part of the plate cylinder, that is, the part without the point, cannot be Scraping effectively can also cause scratches to become dirty.

3. The plate cylinder assembly is not concentric

The plate cylinder assembly is not concentric. Generally speaking, the runout within 10 lines will not affect the registration and product quality. When the plate roller rotates from the side with the larger diameter of the ellipse to the side with the smaller diameter of the ellipse, the distance becomes longer instantly. Since the scraper is an external force acting on the plate roller, there is a time difference during the conversion process, and the pressure of the scraper is relatively reduced in an instant, so that the pressure of the scraper is tightened and loosened in one cycle of the plate roller due to the beating of the plate roller, causing local scratches.

4. Ink viscosity is too high

When the viscosity of the ink increases, its surface tension will also increase accordingly, and the interaction force will also increase accordingly, so that when the scraper is in contact with the ink, the ink will increase, and the impact force of the scraper will destroy its balance point, resulting in the scraper unable to print The ink remaining on the plate cylinder is completely scraped off, which directly affects the quality of the product.