What problems are prone to occur in the printing process of self-adhesive coated paper?

The problems that are prone to occur in the printing process mainly include the following aspects:

1. Improper printing pressure control

Problem performance: printing pressure is too large easily lead to powder, dot imprinting is not clear, and even increase plate wear; If the printing pressure is too light, the impression may not be strong, and it is necessary to blindly increase the ink layer to make up for it, resulting in sticky, slow drying, and poor overprinting.

Solution: The printing pressure should be strictly controlled to make it uniform and appropriate. The ideal printing pressure is in the case of a certain compression deformation of the printing surface, so that the graphic part of the plate on the paper impression is strong enough, while using the minimum pressure.

2. The amount of ink is not reasonable

The surface of the coated paper is coated, and the ink absorption is moderate, but if the ink amount is too large when printing, it will lead to incomplete drying and dirty phenomenon. Especially in the field printing, it is not appropriate to deepen the ink color by increasing the pressure and the amount of ink.

Solution suggestions: The amount of ink should be reasonably controlled, and the method of "deep ink thin printing" should be adopted, that is, the ink should be properly darkened, so that the ink layer is correspondingly thin when printing, which can not only meet the printing color requirements, but also reduce the chance of imprinting over the bottom, and prevent the overlapping color printing.

3. Sticky and dirty problem

Problem performance: The ink absorption of coated paper is weak, the back is relatively smooth, and it is easy to produce sticky and dirty problems when printing a large amount of ink or multi-color overprinting.

Solution: Anti-stick measures should be taken to overcome, such as adding the appropriate amount of anti-stick agent to the ink and then stirring, printing can receive a better anti-stick effect. However, the amount of anti-stick agent should be reasonably mastered to avoid ink emulsification, printing ink layer flower and ink layer gloss decline and other bad diseases.

4. Printability problem

Problem presentation: Each batch of coated paper may have differences in smoothness, pH, absorption, dryness, scalability and surface bonding strength, which will affect the printing effect.

Solution Suggestions: Before being put into use, these characteristics of paper should be tested and analyzed, and corresponding technological measures should be taken according to the characteristics of paper, such as adjusting the viscosity, fluidity, dryness and anti-stick measures of the ink, so as to achieve standardized scientific production and prevent bad printing.

5. Poor printing environment control

Problem expression: Improper temperature and humidity control in the printing workshop will also affect the printing effect. For example, excessive humidity can cause problems such as curling of self-adhesive materials or wrinkling of labels.

Solution: Strengthen the control of temperature and humidity in the workshop to ensure a stable printing environment. When necessary, measures such as heating or humidification can be taken to adjust the workshop environment.

6. Static electricity

Symptom: Static electricity may be generated during the printing process, which causes the self-adhesive label to be difficult to separate, the paper on the receiving table is not received properly, or the paper on the feeding table is skewed and the overprinting is not allowed.

Solution suggestion: Install static eliminator on the printing press or use water spray to eliminate static electricity on the paper. At the same time, increasing the humidity of the printing workshop also helps to eliminate static electricity.

In summary, the problems prone to occur in the printing process of self-adhesive coated paper mainly involve printing pressure, ink volume control, sticky problems, printing suitability problems, printing environment control and electrostatic treatment. Taking appropriate measures to solve these problems can ensure the printing effect and quality.