Today's society has developed to the point that all goods need packaging, and all packaging needs to be printed. Printing is the most important decoration and processing method for product packaging. Packaging without printing is almost unthinkable. Printing plays a role in conveying information, promoting and introducing products. At the same time, for some commodities, printing also plays an important role in anti-counterfeiting. Today's packaging printing is moving towards more refinement and increasing the added value of goods.
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1. The hidden dangers of food packaging inks
In today's increasingly fierce market competition, the competition of food packaging and printing products is not only the competition of product quality, but also packaging safety has become a key issue affecting product quality. How to improve the quality and safety of food and food packaging and protect the health of consumers has become a focus of increasing attention from the government and consumers.
At present, new, beautiful and branded contact materials make the use of ink more and more widely. Almost all food packaging is inseparable from the decoration of ink, but the ink contains a large number of toxic and harmful chemicals, including heavy metals, residual solvents, organic volatiles and polycyclic aromatic hydrocarbons. Therefore, food packaging safety is an important part of food safety. The health and safety of ink is directly related to food safety and people's health. In particular, plastic-based food packaging (including paper-plastic composite materials, aluminum-plastic composite materials and other composite food packaging materials) has a certain moisture permeability and oxygen permeability, coupled with the chemical migration of ink, resulting in the printing ink on food packaging. of harmful substances contaminate food contents. Solvent residues such as toluene in inferior printing ink products are as high as 151mg/m2 (my country's requirement for food packaging is that the total amount of solvent residues is ≤10mg/m2), and the "soluble" lead content is as high as 430mg/kg (the EU and other developed countries have a The "soluble" lead content limit of paint and other products is less than or equal to 25mg/kg).
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Second, food packaging printing ink safety regulations
The Food Safety Law of the People's Republic of China clearly sets forth requirements for food packaging materials and containers, which have significant implications for ink manufacturers, food packaging printers and consumers. The use of green ink has become the only way for environmentally friendly printing. At present, the European Union, the United States, Japan and other countries and regions have long had regulations and laws on ink hygiene and safety, such as Japan's NL regulations (independent restrictive regulations for food packaging materials inks) and the rationality of inks in the German packaging law standards.
my country's first general national standard to regulate food packaging - "General Principles of Composite Films and Bags for Packaging" (hereinafter referred to as "General Principles") has made new regulations on solvent residues, and the individual standards for benzene solvent residues are more. strict. It is stipulated in GB10005 "Biaxially oriented polypropylene/low density polyethylene composite films and bags" that the total amount of solvent residues should be ≤10mg/㎡, of which benzene residues should be ≤3mg/㎡; while in the "General Rules", solvent residues The total amount remains unchanged, but the benzene residues are revised to ≤2mg/㎡.
3. Food packaging printing safety inspection
In recent years, food manufacturers and consumers have paid increasing attention to the safety of food packaging. Food packaging has gradually risen from the original beauty and packaging function to the topic of safety. The health and safety of food packaging is generally controlled from the safety control of raw and auxiliary materials, the control of printing methods, the requirements of environmental facilities and equipment, the establishment of food safety control systems, and the establishment and implementation of good operating practices.
The current packaging hygiene requirements related to ink can be roughly divided into the following categories:
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Total Migration Detector
The first category: the migration of heavy metal elements or the content of heavy metal elements and compounds; the commonly used total migration detectors are used for various tableware, containers and food packaging films, cans or other various food tools, pipes and other products. Determination of Dissolution in Immersion Liquids. The total migration of the analyzed material, which is an indicator of leaching, is carried out by measuring the evaporation residue.
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Gas Chromatograph
The second category: the residual amount of volatile organic compounds, that is, the VOC content related to ink and printed matter; in actual produc