In the printing industry's march into the green development highland, if the printing machinery is a warhorse that clamors for hooves, then the green ink is the “grass and grass” that enables the warhorse to ride the battlefield. It is particularly important to see if food and horses can satisfy the appetites of war horses.

Environmental inks are increasingly favored by printers

In the situation of environmental protection “wind”, many sensitive printing areas, such as food packaging, pharmaceutical packaging, surface printing of children's products, and packaging and printing, have been quietly changing their colors and green. This trend will become even more apparent in the future.

The problem of printing ink pollution is getting more and more attention from all parties. Especially the safety and environmental protection of printing inks such as food packaging and children's toys have become a hot spot for consumers and government departments concerned. The higher the price, especially the printing of export products, will be strictly tested by the environmental protection laws of the importing countries.

At the same time, the production capacity of the domestic printing industry has become relatively surplus. The foreign orders should be the new economic growth point for the printing industry. The printed foreign orders should also meet the requirements of relevant countries' laws and regulations in terms of environmental protection. To meet the requirements of these new printing and consumption trends, printers will increasingly prefer green inks.

In recent years, environmental protection regulations in developed countries such as Europe and the United States have added provisions related to printing, such as the clear restrictions on the emission of volatile organic compounds in the printing industry, which not only increases the content of waste disposal, but also reduces the loss of ink consumption. way.

Offset printing ink has many improvements in terms of low toxicity or no toxicity and no pollution, especially the development speed of UV ink is even more alarming. The environment-friendly ink represented by water-based inks, alcohol-soluble inks, and UV inks for flexible packaging printing is increasingly favored by printers. In the United States, Japan, Germany and France, aqueous inks are increasingly used in plastic film printing.

Flexible packaging printing water-based ink into the mainstream

In June 2000, the United Kingdom banned the use of solvent-based inks to print food packaging films. In 1982, the "Chemical Products Act" was promulgated in Germany. It regulates the protection of the human body in the printing shop, the protection of general health, and the protection of the environment. Austria 1996 The enactment of laws and regulations strictly restricts certain solvent additions and inks. Some solvent components (such as aromatic hydrocarbons) must not exceed 5%.

The regulations on packaging and printing inks such as foods and pharmaceuticals are more stringent. For example, in European and American regions, the content of ethyl acetate and isopropyl alcohol in the solvent residues of food packaging inks must not exceed 5 mg/m2; the US Food and Drug Administration also stipulates that Adhesives and ink types used in food or pharmaceutical packaging are strictly prohibited as long as they are not mentioned in the regulations.

In recent years, China has also made some provisions for food packaging. The status of environment-friendly ink has been continuously improved, and water-based ink has become the main ink type in flexible packaging printing. From the perspective of the development trend of international packaging printing, water-based inks and UV inks have evolved from a single carton printing ink to a variety of substrates and multi-color overprinting.

Environmental protection has become the main driving force for ink innovation. The focus of innovation is mainly on removing volatile organic compounds (VOCs) from the ink, thereby reducing the environmental damage caused by the ink and reducing the use of harmful pigments such as heavy metals. At the same time, in recent years, factors such as the dramatic rise in international oil prices and the reduction in oil resource reserves have further stimulated the enthusiasm for finding new fuels, such as the replacement of non-renewable petroleum materials with renewable oils (such as soybeans, flax and other plant oils).

Special fields give birth to new ink curing methods

In addition to ink formulation, some new ink drying methods are being actively explored. They are used in some special areas of printing requirements. The main ones are trademarks and packaging printing, especially anti-counterfeiting and printing with confidentiality requirements.

These new ink curing methods mainly include: a. Energy curing type. In particular UV and UV/traditional hybrid curing has become a new development trend, its advantages are lower energy consumption and no VOC, instantaneous curing facilitates post-processing of the print, stronger durability and higher print quality Printing can be performed on almost all substrates (including plastics without voids). It is also very easy to switch from traditional inks to UV-cured inks. The main factor currently affecting this way of expanding the application field is the higher cost.

b. reaction curing type. When the ink comes into contact with the paper, some components of the ink react with certain components of the paper and dry and solidify. The ink cures rapidly and there is no environmental problem with VOCs. However, inks and papers that react with each other must be selected for printing.

c. Pressure curing. This is a technique that is transplanted from carbonless copy paper. That is, the ink is made into microcapsule particles. During the printing process, the ink microcapsule particles are pressed to break. The different components of the microcapsule particles react and rapidly solidify. This drying process is free of VOCs and requires no drying device.

d. Tempering curing. This kind of ink shows a solid state at normal temperature. When printing, the temperature rises, and the ink changes from a solid state to a liquid state. When the ink is transferred to the surface of the substrate, the ink film rapidly changes from a liquid state to a solid state, and the drying proceeds quickly. Solvent evaporation, no drying device, but the need to heat printed components, can be achieved in the silk screen. In addition, there are water-based UV curing technology, thermal combustion curing, catalytic combustion curing, vacuum curing and other methods.