Eco-friendly gravure printing ink

Since the 1980s, the rapid development of China's plastic flexible packaging industry has also accelerated the pace of food, daily chemical and pharmaceutical packaging replacement. Although gravure printing can realize flexible packaging printing with various functions and beautiful decorations, the evaporation of a large amount of organic solvents generated during the printing process also brings serious harm to the environment. At present, gravure printing inks and dry composite adhesives used in flexible packaging printing in China still use a large amount of aromatic hydrocarbons and ester ketone solvents. With the increase of people's awareness of environmental protection and health and safety, the requirements for plastic flexible packaging have become increasingly stringent, especially its health and safety, such as the toxicity of solvents, the residual amount of solvents, the determination of heavy metal content, etc., and the environment-friendly gravure printing ink. Development and improvement cannot be delayed.

In theory, the use of water-based plastic gravure ink instead of solvent-based inks now used can achieve environmental protection. However, given the characteristics of water-based inks and the existing printing equipment in China, the promotion of water-based inks on plastic flexible packaging will take some time. Because water-based inks use water as a solvent carrier, the volatilization rate is slow, so the printer is required to have stronger drying, blowing and exhausting capacity; due to the chemical action of water, components that touch water in printing machinery, such as plate cylinders, scrapers , ink pumps, etc. need to have a higher corrosion resistance, corrosion resistance. In this case, the alcohol-soluble ink is more easily accepted by the environment than the currently used toluene-based ink, which solves the problem of environmental pollution and human health damage caused by the use of the benzene-based solvent. Therefore, the alcohol-soluble ink is used as Water-based ink transition products are more easily accepted by users.
Based on the use of foreign ink technology, Zhejiang New Oriental Ink Group, in line with market development, introduced a modified polyester series of alcohol-soluble plastic packaging inks, free of benzene and other aromatic solvents, ensuring the safety and health of packaging prints. .

Alcohol printing ink

At present, the most used area for printing ink is liquid milk packaging film printing. As many beverage and liquid milk producers’ fresh-keeping filling production lines have been launched one after another, the cost of paper aluminum-plastic composite packaging materials has remained high, making the liquid flexible packaging using PE co-extruded film as a base material widely used, thus stimulating packaging printing. The rapid development of printing inks.

Among the plastic intaglio printing inks on the market, most of the products are polyamides or modified polyamides. This type of ink is used for the gravure printing of polyethylene film, and the ink layer has good fastness and good gloss. However, polyamide inks generally have defects such as poor water resistance, poor oil resistance, and resistance to freezing. When printed under a high temperature environment, the ink film tends to become sticky and soft, and at low temperatures, freezing phenomenon occurs. In the process of filling, transporting, storing, and transporting the liquid packaging production line, high temperature sterilization or freezing and the like are required. Therefore, the polyamide type surface printing ink cannot satisfy the requirements for liquid packaging. However, after the polyamide-based binder was changed to polyester (modified), it had the characteristics of alcohol dissolution, water resistance, boiling resistance, and anti-hydrogen peroxide sterilization, and radically improved the defects of the polyamide type surface printing ink. The ink can be used for high-pressure polyethylene film, BOPP (heat-sealable) film printing, and packaging of higher-demanding biscuit products. In addition, due to its good high temperature resistance properties, it has been used in beverage packaging for paper aluminum plastic materials.

New Oriental's 313FA ink is the printing ink of this kind. It is safe and hygienic. It eliminates the contamination of the contents of the packaging bag and meets the food preservation requirements.

Alcohol-soluble composite ink

When printing plastic bags, if the ink or solvent used contains toluene, since the boiling point of toluene is 110°C or more, it is impossible to evaporate completely in the process of printing and compounding, and therefore the odor will remain on the package. Some color printing factories that specialize in printing milk powder bags spend a lot of financial and material resources to control the odor of the bags, such as the introduction of high-speed machines and the use of quick-drying solvents, but they cannot solve the problems fundamentally. Now they use alcohol-soluble compound inks. Can reduce or avoid residual odor well.

Alcohol-soluble compound inks are preferably used with alcohol-soluble binders to achieve the best printing quality and composite strength, and at the same time, it is also possible to ensure that the solvent residue of the packaging bags is the lowest. Alcohol-soluble composite ink should not be used ester-soluble polyurethane adhesive, so as not to cause ethyl residue. New Oriental's alcohol-soluble compound ink 303LV, using alcohol solvent as a diluent, the release of the resin to the solvent is good, the residual solvent is very low after printing.

At present, there are not many domestic manufacturers that can produce alcohol-soluble adhesives. When different types of adhesives are used in combination with Chaolifu 303LV ink, the final composite strength will be different, as shown in Table 2. Because the alcohol solvent in the alcohol-soluble ink will affect the cross-linking reaction of the binder main solids, thereby reducing the adhesiveness of the inner and outer membrane; and the use of ester-soluble binders, you should choose to have a greater degree of alcohol tolerance lamination Agents, such as PU2975 polyester adhesives, to improve their composite quality.

China has now begun to formulate relevant packaging regulations, and the health and safety requirements for food packaging will gradually be in line with international standards. Environmental-friendly ink is the only way to achieve hygienic and safe packaging and printing. At present, the promotion of alcohol-soluble ink and alcohol-soluble compound ink will promote the rapid development of flexible packaging inks to environmental protection.

Source: China Ink Web