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Off-ink phenomenon of self-adhesive materials
- Sep 01, 2017 -

Monlchamus phenomenon in the paper self-adhesive material printing in a relatively low probability, more in the film material, which is mainly due to the surface tension of the film material instability. In general, the cause of film-type material printing ink is thin film material surface tension, UV curing bad, ink additive dosage too large.

1. Thin film surface tension caused by low ink

Generally speaking, the film material surface tension needs to reach more than 38 to ensure normal printing, to make the ink firmly attached, the requirement to reach more than 42. If the printing process appears in ink phenomenon, can be used to test the surface tension of the material, if below the standard, it is recommended to use the mechanical corona or coated bottom oil method to increase the surface tension of the film material, in order to achieve a better ink adhesion effect. If there is no condition to use the above two methods to solve the problem, you can also use low surface energy inks to try to solve. At present, a lot of ink manufacturers are provided specifically for the low surface energy material inks, printing enterprises can be tested to find a matching with the label materials to solve this problem.

2. UV curing caused by bad ink

Off ink and UV ink curing effect has a great relationship. If the power of the UV lamp is insufficient, or the printing speed is too fast, there will be a "false-dry" phenomenon, this situation can easily lead to the ink. The so-called "false-dry" means the surface of the ink has been dry/cured, and the interior is not completely dry

Dryness/curing. It is particularly clear that this phenomenon is caused by a large area of printing ink in the field pattern. This is because the field pattern with a large amount of ink, ink layer is not easy to completely cure. In addition, sometimes printing ink only a certain color off the ink is more obvious, the most common is black ink seriously. This is because UV light is difficult to penetrate the black ink layer, and in most cases black ink will be arranged in the last color group for printing, curing the total length of the shortest, not easy to complete curing.