The method to judge the adhesion fastness of printing ink is to use glass paper pressure-sensitive adhesive tape to test. The printing fastness varies with the type of ink. The main reasons for the poor adhesion of ink are as follows:
1. Misusing ink model or mixing with different ink. For different types of substrate, to choose different types of ink, using the wrong will produce poor bonding. For example: cellophane gravure ink is nitrocellulose series, printing paper ink is rosin system, otherwise, it will produce the phenomenon of weak adhesion.
2. The surface condition of substrate is poor. Such as polyethylene, polypropylene, nylon, polyester and other plastic film, its surface is very smooth, low surface energy, no affinity for ink, ink is not easy to adhere to it, so it must be treated, change its surface condition and chemical structure, increase surface roughness, enhance the polarity of components, in order to improve the ink adhesion fastness.
3. Hazards caused by improper use of additives. Various additives contained in plastic film. Such as antistatic agent, smooth agent, plasticizer and so on. Once these additives float on the surface of the film, the adhesion of the ink to the substrate is damaged, and the printing fastness is greatly reduced.
4. Surface moisture absorption. Such as nylon, ordinary cellophane, vinyl resin and other raw materials are easy to absorb moisture, and there is a layer of water molecular film on the surface to separate the ink from the substrate, which greatly reduces the printing fastness. The material should be kept under the condition of RH = 50% ～ 60% and T = 18 ～ 23 ℃, so as to avoid damp.
5. Ink swelling or solid precipitation, resulting in poor adhesion.
6. Insufficient heating. Gravure printing, dryer to provide sufficient heat, heat shortage, poor viscosity. This is because gravure ink in the binder resin is a hot-melt adhesive polyamide resin, only when it reaches a high enough temperature, it has viscosity. However, if the temperature is too high, the film will wrinkle or stretch, resulting in poor dimensional stability, affecting overprint, and bring adverse cooling, resulting in adhesion after winding.
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.
We uphold the integrity of cooperation, good quality, good service business philosophy, won the industry's approval, products sold to all over the world; welcome friends from all walks of life to inquire, visit our factory to investigate guidance and business negotiations.