Plastic gravure ink application range

Plastic gravure inks are mainly used in food packaging, salt packaging, cosmetic daily product packaging, and pharmaceutical packaging. Food packaging is based on composite inking ink, some candy paper with table printing ink; cooking packaging using high-temperature cooking ink, the general vacuum packaging is to use polyester ink; dairy packaging should use water, acid, temperature resistant ink; Pharmaceutical packaging and cosmetic packaging are mainly based on polyester ink; some manufacturers use table printing inks, some manufacturers use compound printing inks, but more manufacturers use polyester inks; with the packaging market grade There are more and more products that use composite inks and special special inks.

The application of water-based ink is the trend

At present, gravure printing inks used in China contain a large amount of organic solvents (about 50%). Toluene, ethyl acetate, butanone and other solvents have low boiling points, high volatility, aromatic hydrocarbons, and are toxic and flammable. They are the major sources of environmental pollution.

Intaglio printing inks are generally made of chlorinated polymers. In the ink production process, the chlorinated polymer needs to be dissolved using a strong solvent (such as toluene and other aromatic solvents), and the viscosity of the ink is adjusted with toluene during the printing process. Chlorofluorocarbon gases that are volatilized during the production of chlorinated polymer inks can destroy the atmospheric ozone layer. The use of aromatic solvents (toluene) in the printing process can harm workers' health and safety (fire hazards). In addition, the problem of ink solvent residues in packaging products is a concern. Benzene can easily remain in the dry ink film layer (low-speed printing requires the use of xylene to adjust the drying speed of the ink, xylene is more likely to remain), and benzene residues can contaminate the food or articles in the package. Although the gravure alcohol ester ink is the leader of the alcohol-soluble ink, although there is no benzene-free ketone, it will still pollute the environment and there will be residual solvent.

The production of plastic gravure inks is subject to laws and regulations such as Fire Protection Law, Labor Safety Law, and Health Law. Therefore, it is an inevitable trend to actively develop and apply green inks that meet the requirements of environmental protection. Water-based gravure ink as a solvent-based ink replacement system has attracted the attention of various sectors, and the ink-based water-based packaging film printing is also under development.

On the whole, the important reason why water-based gravure inks have not been popularized further is that the printing performance and quality still cannot meet the standards for printing of solvent-based gravure inks. Mainly due to the large surface tension of water, resulting in difficult to wet the ink; water does not volatilize, printing speed can not go up if you want to obtain gravure printing ink printing speed and printing quality, not only water-based ink itself requires advanced technology improvements , And gravure equipment and printing plate roller also need to be improved.

For example: Change the corrugated roller or electric engraving roller with a printing plate roll depth of about 38 μm to 42 μm to a laser printing plate roll with a depth of about 24 μm to 28 μm, and the printing roller needs to be resistant. Corrosion materials to make. There is also a need for a more powerful and effective ink drying system, as well as equipment components such as ink squeegees, on the printing press. These improvements all require considerable investment and a long period of time.

Since the water-based gravure ink is removed for printing on paper, plastic film printing cannot completely replace the solvent-based ink. Therefore, the ink industry has been working hard to develop alcohol-soluble inks with less environmental pollution. Alcohol ester composite plastics gravure inks have low odor, no benzene, ketone and other characteristics. Alcohol-soluble inks can help us solve toluene-based inks. The benzene damage and benzene residues that are caused by health affect the quality of packaged foods.

The production of such environmentally friendly inks will certainly increase the competitiveness of gravure printing in the field of plastic flexible packaging printing. In Japan, South Korea and Southeast Asia, toluene inks have been eliminated and replaced by alcohol-based gravure inks. In Europe, it is strongly advocated that flexo printing and gravure printing use alcohol-soluble ink (benzene dissolving ink is prohibited). The development of water-based ink in the United States has taken the lead. Alcohol-soluble ink has been gradually applied in the domestic gravure printing industry. It can be foreseen that in the near future, the development trend of ink for flexible packaging in China is: benzene-soluble ink will be replaced by alcohol-soluble ink, and water-soluble ink will have great development. space.

At present, the domestic gravure printing industry is looking forward to: a single solvent (ease of recycling), surface printing, printing, compounding, cooking, all kinds of plastic films are applicable, any climate is adaptable (can reduce the production of enterprises (Cost), high-speed, medium-speed, low-speed, low-cost, universally-recognized gravure inks appear in the market.

Advice on the use of ink manufacturers

The printing speed of foreign printing presses is fast, the production environment is more standardized, and the varieties are bulky and color-specific. Therefore, the requirements for inks are limited to high solid content, low viscosity, brilliant color, and strong coloring power. In China, many low- and medium-speed printers are the main products, and the domestically-made printers are uneven, with large performance gaps, small quantities of products, various types of products, relatively poor production environments, and non-standard operations. Therefore, the requirements for inks are more diverse, requiring not only strong ink adaptability, good fluidity, but also low prices. In addition, due to the operator's mentality, using imported ink, printing problems, choose to adjust the press. In reverse printing with domestic ink, problems are usually found in inks and plates.

The gravure printing system of domestic gravure printing machine has poor ink circulation system (except for the high-speed printing machine delivering ink supply type), and there are many small and medium packaging color printing plants that do not even use the ink circulation system. Some operators do not understand the law of ink on gravure printing. Little is known about the performance of inks. Ink dilution is not in place. According to observations, the wastage rate of ink is an average of 25% to 30%. There are many small-scale packaging printing plants and even wasteful rates. 40%~50%). Therefore, it is more necessary to popularize the basic knowledge education of the production technology of plastic flexible packaging, as well as technical services after ink sales.