Application of gravure printing ink for environmental protection flexible packaging

Since the 1980s, the rapid development of China's plastic flexible packaging industry has promoted the continuous upgrading of food, daily chemical and pharmaceutical packaging. The intensification of the industrialization process has brought about more environmental problems. Governments in various countries have formulated policies that require the development of the economy to better protect the environment and natural resources. People's increasing awareness of environmental protection and health and safety have prompted us to tighten the requirements for plastic packaging, especially the requirements for hygienic safety indicators, such as solvent toxicity, residual solvent content, and heavy metal content.

Soft-pack gravure printing provides people with different functional packaging bags, but it also brings serious environmental negative effects due to the volatilization of large amounts of organic solvents. At present, in China's flexible packaging inks and dry composite adhesives, volatile organic solvents such as aromatic hydrocarbons and ester ketones are widely used, and people in the printing industry generally believe that only by improving the environmental pollution in the gravure printing process can gravure printing be ensured for a long time. The further development of the industry, otherwise it will face the possibility of elimination.

In the future, water-based plastic inks will certainly replace organic solvents that are currently used. However, in view of the characteristics of water-based inks and the state of the existing printing machinery and equipment in China, the promotion of large-scale water-based inks on plastic flexible packaging still needs time. Mercury ink uses water as a solvent carrier and the evaporation rate is slow. This requires the printer to have stronger corrosion and rust resistance, such as spot roller, doctor blade and ink pump. Therefore, compared to the current toluene-based inks, alcohol-soluble inks are easily accepted by the environment, solving the environmental damage caused by the use of toluene and harm to human health, and due to the high boiling point of aromatic hydrocarbons, easy Retention causes print solvents to have many residues, odors, and practical printing problems that affect the contents of the package.

New alcohol printing ink

At present, the well-known manufacturers in the food industry are optimistic about the beverage and liquid milk markets and successively launch related production lines. However, the cost of paper-plastic compound brick packaging is still high, and it cannot meet the needs of fast-food and popular liquid milk packaging development. Under the pressure of competition, food companies began to focus on the decline in the cost of related auxiliary materials. The packaging of milk and other contents using a PE co-extruded film as a substrate not only achieves a shelf life of 7 to 30 days, but also significantly reduces the cost of packaging. It is against this background that the liquid flexible packaging has grown rapidly and has driven the rapid development of printing ink for printing liquid packaging. In the market of plastic intaglio printing inks, most of the polyamides are changed to the binder. This type of ink is used for polyethylene film, and the film has good adhesion and good gloss; but polyamide inks Poor water resistance, grease resistance, and resistance to freezing are common ubiquity. The use of this type of ink for high-temperature printing in the summer is apt to produce stickiness and softening, and freezing occurs during low-temperature printing in winter. Liquid packaging in the filling, circulation, storage and other post-processing, through high-temperature sterilization or freezing process, therefore, the inherent defects of polyamide printing ink can not meet the liquid packaging requirements. Chao Lifu 313A ink is polyester (modified) as the connecting material, with alcohol, water, boiling, anti-hydrogen peroxide sterilization features, fundamentally improved the polyamide type table printing ink defects, put an end to the bag The contamination of the contents ensures the hygiene and flavor of the food. The ink is mainly used for high pressure polyethylene film, such as liquid packaging, export daily necessities outer packaging. At the same time can be used for BOPP (heat seal) table printing, making high-demand biscuit packaging. In addition, due to its excellent high temperature resistance characteristics, it has been successfully used in beverage packaging with Tetra Structure. The measured data of various indicators are shown in Tables I and II.