Causes and solutions of printing back sticking
Phenomenon: the phenomenon of ink transferring to the opposite side of the film or sticking with the film when the printed matter is rolled up and piled up.
reason:
1. Solvent separation: ink solvent composition has a greater impact (especially slow drying solvent). Version depth is too deep or multicolor overprint, the absolute amount of solvent volatilization is large, the ink surface drying is too fast, the internal solvent can not volatilize, resulting in the occurrence of sticky back.
2. Temperature: the binder in the ink is softened by heating, and the existence of a small amount of solvent, the softening point of the ink is lower. When winding up, the ink is softened due to heating in the oven, which is caused by heat sticking.
3. Pressure: when the winding pressure is high, it is easy to cause sticking back, especially for the film with high thermal shrinkage, after winding and cooling, the winding core pressure becomes very large, which is easy to cause sticking back. When the direction of the printing pattern is consistent with the printing direction, the place with ink after winding is thick, resulting in excessive pressure in the place with ink, causing sticking back.
4. Time: printing materials are easy to stick back if they are kept for a long time.
5. Printing substrate: the substrate contains plasticizer, lubricant, antistatic agent, antioxidant, stabilizer and other auxiliaries, which can cause adhesion. Plasticizer is a non-volatile solvent that can migrate to the ink film to soften the coating. This problem is difficult to solve. The lubricant and antistatic agent will migrate to the surface of the film, which will make the ink worse and the ink film soften
6. Contents: spices, animal and vegetable oils, fiber plasticizers, antistatic agents and textile auxiliaries in food can be transferred into ink through the film to soften the coating.
Countermeasures:
1. Choose the appropriate diluent.
2. The printed matter must be cooled.
3. The winding pressure should be small. The winding volume and stacking weight should be small.
4. Keep the pressure low during long-term storage (such as longitudinal accumulation).
5. The amount of film plasticizer produced in winter is too large to be used in summer. It should be indicated in the name of the film.
6. Before printing, the proper ink should be selected according to the content and package composition.
Dongguan Beite packaging materials Co., Ltd. - located in Dongguan City, the world's manufacturing city, is a subsidiary of Beite packaging (China) Co., Ltd., with a plant area of 6000 square meters. It is a flexible packaging enterprise integrating R & D, production and sales. It has a complete set of domestic advanced production equipment, a scientific and humanized management system and a group of experienced technical personnel For backing, to provide customers with quality products and first-class service.
The company produces composite bags, roll film, fruit bags, aluminum foil bags, suction mouth bags, self-supporting bags, zipper bags, anti-static bags, special-shaped bags, etc., which are suitable for the internal and external packaging of food, daily chemicals, electronics, toys, medicine, cosmetics, industrial products and other industries.
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