PET film is a kind of polar film with 45-50dyn surface tension without treatment. It is also a film with good firmness no matter what type of plastic ink is printed on. However, when the two-component polyurethane adhesive is dry compounded with other films, especially with PE film, sometimes the printing ink layer will be adhered from the PET film and the delamination occurs (the deinking of thicker PE film is more serious). That is to say, the printing ink layer on PET film, after compounding, part or all transfer to the inner film. So, what are the reasons for this? What are the ways to avoid it?
As PET film has excellent barrier, anti leakage is also very strong, so the solvent is difficult to penetrate, relative ink solvent suction is poor. The adhesive (resin) of plastic surface printing ink has good affinity with PET film, so printing on PET film has higher firmness than printing ink in plastic composite. In fact, the transfer of ink layer after compounding of printed PET film has nothing to do with the use of surface printing ink. On the contrary, using compound inner printing ink is more likely to cause ink transfer.
How to avoid ink transfer
Attention should be paid to the following aspects when printing and dry laminating PET films:
1. As far as possible on the ink, ink to dry (dry), to prevent ink false dry phenomenon (especially when using chlorinated polypropylene composite plastic ink printing). If the printing speed of the printing machine cannot be turned on and the drying oven has poor effect, the printed matter can be rewound once, and blown or placed for some time during rewinding, and then compounded after the ink hardens (when it is used after printing, it is better to rewind and blow to prevent adhesion of printing film).
2. When compounding, the amount of glue must be small, and the solvent of compound glue should be volatilized as far as possible when passing through the drying channel (it is necessary to check whether the exhaust system of the drying channel is unblocked, and the composite hot drum temperature of the laminating machine should not be lower than 70 ℃.
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.
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