The development of China's flexible packaging industry began in the early 1980s, when Dalian Dafu Color Printing Company introduced the first flexible packaging color printing equipment from Fujifilm. After 20 years of development, China's flexible packaging industry has reached a considerable scale and a certain level of technology.
According to incomplete statistics, as of 2004, China already had more than 700 imported flexible packaging production lines, and no less than 8,000 small and medium-sized production enterprises had purchased home-made flexible packaging production equipment. Each year, the country consumes more than 4 million tons of plastic film substrates (excluding aluminum foil and other substrates), and soft packaging inks use 7-8 days of tons, and adhesives about 80,000 tons. It can be seen that the flexible packaging industry has become a high-growth emerging industry in the packaging industry.
The status of flexible packaging ink market
1. Status Quo of Japan's Flexible Packaging Ink Market
Let us first understand the history of ink development for flexible packaging from Figure 1. According to the packaging application, cooking packaging accounted for 20%, boiled packaging accounted for 30%, general packaging accounted for 50%: According to the composite method, dry compounding, PP extrusion compounded accounted for 30%, PE extrusion compounded accounted for 40%.
It can be seen that in the 1980s, Japan had rarely used chlorinated polypropylene inks, accounting for only 20:6 of the market share. By the end of the 20th century and the late 1990s, Japan had all adopted polyester (one-liquid) type inks, and now all have been changed to modified polyester inks that do not contain benzene-based solvents, and water-based inks have been used in production practices.
2. Development Status of China's Flexible Packaging Inks
As far as plastic flexible packaging inks are concerned, China now mainly uses chlorinated polypropylene type OPP composite inks, polyamide type surface printing inks, and polyurethane type inks. See Table 1 for specific data.
At present, there are more than 400 domestic ink production enterprises with an annual output of approximately 150,000 tons, accounting for only 5.6% of the world's total output. Among them, the ink produced by the ink joint venture established in the 1990s accounted for 70% of the total output.
Polyamide type ink is the earliest industrialized production of flexible packaging ink in China. It adheres firmly to polyolefin films, has good printability, and has good print glossiness. It can be used to produce alcohol-soluble inks. The main surface ink type. Due to its low cost and good sanitation, alcohol-soluble polyamide printing ink still has a lot of room for development. However, polyamide resins have the disadvantages of poor temperature resistance, poor resistance to oils and water, and poor water resistance, which restricts the application of polyamide inks on flexible packaging.
The chlorinated polypropylene ink was introduced when China introduced the flexible packaging gravure production line from Japan in the 1900s. It is mainly used for printing in BOPP film. Due to its adaptability to the needs of the multi-layer composite flexible packaging market, it has become the most widely used composite printing ink in China, accounting for more than 50% of the market share. However, this type of ink has many drawbacks. First of all, chlorine-containing resins such as chlorinated polypropylene are not safe, and residual chlorine can contaminate foods. Second, the use of aromatic solvents such as toluene as the main solvent does not equalize environmental protection requirements. Finally, it is only good for OPP materials. The printing suitability, general composite strength, incompatibility with high temperature and other defects in the application also limit the development of this type of ink. Therefore, as the market continues to improve the packaging hygiene requirements, the market share of this type of ink will continue to decrease until disappear.
Among the three major categories of inks, although the production and application of modified polyester inks started relatively late in China, they have experienced the most rapid development in the market in the past two years. From the history of the development of inks for Rizhao's flexible packaging, it can be seen that Japan replaced the chlorinated polypropylene ink with modified polyester ink in the mid-1990s. Polyester ink has a good adhesion to a variety of substrates, good gloss of printed products, excellent temperature resistance, can be used for table printing ink, can also be used for printing composite ink.
China's flexible packaging manufacturing enterprises are mainly small-scale color printing manufacturers. The technical content of soft packaging products produced is not high, and the homogenization of products is very popular. Due to the fierce competition in the food flexible packaging industry, flexible packaging manufacturers often pay more attention to the reduction of product costs, while ignoring the technical requirements and hygiene requirements of the products.
China's printing ink for flexible packaging lags behind in safety and hygienic performance. Toluene and other aromatic hydrocarbon solvents are still in great use. Toluene is a moderately volatile solvent and has good affinity for polyolefin films such as BOPP. In the printing process, if the process is not controlled properly, it may lead to excess toluene solvent residues.
The toxicity of benzene solvents is large, long-term exposure can damage the human nervous system, and even lead to leukemia. In addition, the direct discharge of large amounts of organic solvents will also have a greater negative impact on the atmospheric environment. In 1995, the Japan Gravure Printing Industry Federation issued a proposal to promote benzene-free, and many end-users demanded that the residual solvent content of food packaging be controlled below 10mg/m2.
At present, in the hygienic standards for food packaging bags in China, the amount of residual solvents is required to be controlled within 10 mg/m2, and there is no clear indication of which type of solvent, and the recommended standard requires that the residual amount of toluene be less than 3 mg/m2.
Development trend of ink for flexible packaging
In Europe and the United States, inks for flexible packaging can only use solvents such as alcohols, esters or water, and aromatic hydrocarbon solvents are not allowed to be used in foods. In packaging printing inks such as toys, ketone solvents are also strictly prohibited for producing or diluting ink because of their large odor. In food packaging inks used in Europe and the United States, the amount of nitrocellulose is the largest, and the requirement for solvent residues is that the content of ethyl acetate and isopropyl alcohol must not exceed 5 mg/m2.
Water-based inks represent the most advanced technology for the development of flexible packaging inks. Water-based ink uses water, alcohol, etc. as a solvent, safety and health, and adaptability to the operating environment is extensive. Completely overcome the solvent-based ink in the summer high temperature, high humidity environment due to ink absorption and affect the use of the problem. In China's mainland market, water-based inks are widely used in the field of flexible packaging due to limitations in technology, equipment, and competitive environment.
In summary, the pattern of China's plastic gravure ink will undergo tremendous changes, benzene inks will soon be eliminated, and non-benzene alcohol-soluble ink will become the mainstream product of food flexible packaging ink. After years of hard work, Zhejiang New Oriental Ink Group has developed benzene-free or alcohol-soluble inks suitable for plastic film printing.
Conclusion
Since gravure printing technology entered China, it has been showing a steady development trend, and the development prospects are still seen. In China's food plastic flexible packaging industry, gravure printing has an absolute advantage, which is different from other countries such as Europe and the United States. In large supermarkets, food that catches your eyes. The flexible packaging of daily chemical products is gravure products, but in Western Europe, flexo printing accounts for more than 70% of the plastic packaging of food, and the volume of gravure food packaging bags is still decreasing.
With China's accession to the WTO, the requirements for plastic flexible packaging will gradually be in line with international standards. The country will gradually formulate more stringent standards. Manufacturers who supply raw materials for flexible packaging manufacturers must plan ahead and adjust their technological orientation to meet the needs of the development of the times before they can The market is invincible.
Source of information: pack.cn