Application of Aluminum Foil Ink

Abstract: In this paper, according to the characteristics of aluminum foil ink printing and post-processing requirements, the functional characteristics of aluminum foil special ink are introduced; and the production process of two different structures of fruit milk cover posts is compared to provide reference for optimizing the process flow of color printing manufacturers.

Keywords: ink, aluminum foil, cover sheet, PTP, application.

Among the packaging materials, aluminum foil (AL) is mainly used as the outer layer material and the intermediate composite barrier layer material. The difference in the production process can be divided into two kinds: hard aluminum and soft aluminum. Hard aluminum is calendered from aluminum sheet, cleaned by surface treatment, and directly coiled without high temperature vacuum annealing. Most hard aluminum thickness is 20 ~ 35um, can be applied to pharmaceutical blister packaging (PTP), direct surface printing of aluminum foil. Soft aluminum is made of hard aluminum by high temperature vacuum annealing, the surface after high temperature, cleanliness increases, the surface oxidation thickness relative increase. Generally used in composite flexible packaging, general thickness of 7 ~ 15um, such as cooking bags (NY / AL / CPP), fruit milk cover posts (PET / AL / CPP), candy paper (AL / paper) and so on. I analyze the application of aluminum foil on the market, printing directly on the surface of aluminum foil, mainly distributed in pharmaceutical blister packs (PTP), beer labels, covered posts (AL / CPP), candy paper (AL / paper) and so on. In order to meet the needs of the market, Zhejiang New Oriental Ink Group Co., Ltd. successfully developed two kinds of aluminum foil special inks; Wanda 992 type, 993 type aluminum foil special ink.

Pharmaceutical blister packs (PTP) are generally printed directly on the surface of a hard aluminum foil with a thickness of 20 to 25 μm. The protective layer is printed on the surface, and the coating is heat-sealed on the reverse side. Then, it is heat-pressed with PVC. The instant temperature is above 200°C. The pressure is maintained at 2kg/cm. Because the ink is directly printed on the surface of the aluminum foil, sometimes there is not even a protective printing layer. Therefore, the ink printed on the surface of the aluminum foil is required to have good affinity and high temperature resistance, otherwise the phenomenon of discoloration and deinking may easily occur. In China, the number of aluminum foil special inks that can meet the requirements of pharmaceutical packaging manufacturers can be counted. The special type 992 aluminum foil ink produced by Zhejiang New Oriental Ink Group is one of the best. At present, the product is used in pharmaceutical packaging manufacturers in the Pearl River Delta, Jiangsu, Zhejiang, and the three provinces of Northeast China. Through information feedback, the 992 product can replace the same type of imported products and has considerable price competitiveness. 992 type aluminum foil special ink not only meets the technical requirements of the aluminum foil and PVC suction cover heat compression, but also has excellent solvent release, high transparency, give full play to the aluminum foil itself has a metallic luster.

With the development of the food industry in China, various types of fruit and milk beverages and hobby beverages are becoming more and more abundant on the market. A considerable part of this type of product packaging is filled with PE, PET bottles, heat-sealed, and then sterilized by high-temperature cooking. At present, there are two types of cover posts for production heat sealing:

PET/AL/CPP, AL/CPP. In the overseas, the packaging of the same type of products is generally based on the latter; in addition, from the perspective of packaging cost accounting, the cover of the AL/CPP structure is the dominant direction of development, and the main factor that currently restricts the development of the structure is domestic use of the product. The lack of special foil for aluminum foil. When the cover is AL/CPP or AL/LLDPE, the ink is printed directly on the surface of the aluminum foil. When the contents are filled and the sterilizing process is performed, the water in the pot inevitably contains oil and is weakly acidic due to the leakage of the contents. Therefore, such severe conditions have a considerable effect on the ink layer printed on the surface of the aluminum foil. The aluminum foil ink used for this product must be able to withstand long-time high-temperature cooking, and has excellent water resistance, grease resistance, acid resistance, in addition, also need a good gloss retention, not because of prolonged cooking And the gloss disappeared. Zhejiang New Oriental, with its strong development capabilities and years of experience in high temperature cooking inks, developed the Wanda 993 high-temperature cooking (two-fluid) aluminum foil ink for the revolutionary production of lidtie production. Variety.

Aluminum foil printing is a technically demanding process in the packaging industry. It not only requires strict selection of printing equipment and raw materials, but also requires the printers to be skilled in the operation technology and have a good comprehensive ability. In the selection of aluminum foil, it is best to use well-known manufacturers' products. The surface is highly clean and there is no uneven oil pollution. It is required that the surface energy of 31i is better than the above, and the surface energy of imported aluminum foil can reach 32 dyne. When aluminum foil is printed, it is generally necessary to use a special aluminum foil printing machine because the creases are easily generated when the foil is passed through the guide roller. When using aluminum foil printed by a gravure printing machine, the drying path of the printer is required to be strong and the air volume is large, and the ink can be completely dried. In the printing of 993 aluminum foil ink, it is possible to adopt a process of compounding, then printing, and then curing, but in the compounding, the secondary pollution of the aluminum foil on the dryer is to be prevented. 993 type aluminum foil ink is a two-liquid reactive ink, so when the ratio is required, the amount of hardening agent should be properly adjusted according to the customer's specific requirements, generally about 8%.

So far, no film can really replace the functional properties of aluminum foil: high barrier properties, metallic luster. People's increasing demand for packaging has led to more and more aluminum foil prints. This growing market, who will be able to take the lead, will play an important role in its future competition.

Reprinted from: Ink Information