Benzene free printing technology will be the mains

2022-09-19
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Food packaging: the use of benzene free printing technology will be the mainstream

the national food packaging safety technology seminar was recently held in Chengdu, Sichuan Province. With the theme of "safe food, healthy packaging, benzene free printing", the conference discussed new technologies and materials such as benzene free inks for food packaging safety in China

at the national food packaging safety technology seminar, the participants put forward their opinions on the current situation of harmful substance residues in food packaging affecting food safety. The safety situation of food plastic packaging materials in China is very serious. Many food plastic packaging materials in the market are difficult to meet the national requirements for food safety, health and environmental protection. In recent years, the sampling qualification rate of packaging bags in various places is generally low, and the qualification rate is only 50% - 60%. The main reason for disqualification is that benzene residues exceed the standard. CCTV's weekly quality report once broadcast the Lanzhou "toxic milk powder" incident. Due to the excessive residue of toluene and xylene solution, the unqualified rate of food packaging bags was as high as 50%. Benzene solvents are highly toxic. If they penetrate into the skin or blood, the residues of benzene solvents will harm human blood cells and hematopoietic function with the blood, damage human nervous system, and cause leukaemia, which constitutes a patent protection group. FDA lists them as carcinogenic chemicals. Therefore, the United States, Western Europe, Japan and other developed countries expressly prohibit the use of benzene solvents in food packaging and printing. However, there is still no clear regulation in China. In the production of food packaging films and bags, benzene (toluene, xylene) solvents are widely used as solvents for inks and adhesives, and there is no management and supervision. At present, the relevant departments have decided to strictly manage them

the impact of plastic packaging materials on food safety

Plastic packaging materials in China, especially soft composite packaging materials for food and drugs, have developed rapidly in the past 20 years. There are not only many manufacturers, but also many varieties of products, and the quality has reached a certain level. However, in the process of the rapid development of the packaging industry, we focus on the scale, output, physical and mechanical properties, high and low temperature resistance requirements, medium erosion resistance and other aspects, but we do not pay enough attention to the health and safety performance of the packaging materials themselves. Therefore, many manufacturers of composite packaging materials have some unsanitary and unsafe hidden dangers in the purchase and use of raw and auxiliary materials, the improvement of production conditions, and the detection of finished products; Many food and drug manufacturers do not consider the impact of packaging materials on the health and safety of packaging materials and human body, only pay attention to fastness, strength, appearance and price, and at most care about whether there is peculiar smell. Generally speaking, in the past, people paid little attention to the potential impact of packaging materials on the health and safety of food and drugs and the global environment. Therefore, there is still a big gap between the health and safety quality of packaging materials in China and the world advanced level. In the past two to three years, the state has supervised and inspected the hygiene and safety of food itself, implemented the reassuring food project, and implemented the QS certification and market access system. Since June, 2005, the health and safety problems of food packaging materials have been supervised and tested. The media has exposed some benzene exceeding the standard in food packaging bags, which has aroused great concern of the whole society. This is an important measure taken by the Chinese government to put people first and protect the safety and health of consumers, and it is a manifestation of social progress

most of the inks printed on composite packaging bags are organic solvent gravure inks containing methylbenzene and xylene. Among them, there are two aspects closely related to food hygiene and safety or human health:

the first is benzene solvents. It is not allowed to be used in gb-9685 standard, but it is still widely used in the actual situation, which is very inappropriate. The boiling points of toluene and dimethylbenzene both exceed 110 ℃. During the printing process, the drying temperature is only 70 ℃ - 80 ℃, rarely more than 90 ℃, and the speed is very fast, up to 150 meters or even 250 meters per minute. The solvent cannot be completely removed, and there will always be some residue in the ink layer. If absorbed by the human body, it will damage the human nervous system and destroy the hematopoietic function of the human body, causing typical permanent benzene poisoning symptoms such as vomiting, insomnia, anorexia, fatigue, decreased white blood cells, decreased resistance, etc., which accounts for a large proportion of occupational diseases (such as footwear, luggage, paint, decoration, etc.)

second, there are heavy metals (lead, cadmium, mercury, chromium, etc.) and substances such as aniline or fused ring compounds in the pigments and dyes used in the ink. Lead in heavy metals will hinder children's physical development and meet any requirements for intellectual development. Mercury will produce harmful effects on human nerves, digestion, endocrine system and kidney. It is necessary to establish and improve the comprehensive evaluation criteria and industry standards for plastic granulator equipment, especially on the fetus and infants, and also damage the human brain and lead to death. Cadmium is taken from desktop database; Query module will cause bone damage, while aniline or fused ring dyes are obvious carcinogens, which pose a great threat to human health. Therefore, the harmful substances in the printing ink of packaging bags have an obvious and serious impact on food hygiene and human health. In addition to the base film and ink, the health and safety of composite adhesives are also important. In gb-9685 standard, only maleic anhydride modified polypropylene and polyurethane adhesives are allowed to be used in food packaging, while single component pressure-sensitive adhesives with benzene as solvent are not allowed to be used

benzene free printing technology is the direction of future packaging

at present, China's flexible packaging inks are close to 50000 tons, of which chlorinated polypropylene inks account for more than 40%, polyamide inks account for more than 30%, polyester polyurethane inks account for nearly 20%, and others, such as alcohol based inks, account for less than 5%. Polyamide ink was the first to be industrialized in China. Due to the shortcomings of poor temperature resistance, poor oil resistance and poor water resistance, the amount of polyamide ink is decreasing year by year. Chlorinated polypropylene ink has become the most used variety in China at present because of its good adhesion fastness to BOPP. However, due to the residual chlorine and aromatic hydrocarbons such as toluene brought into the ink production, using it as a solvent may cause food pollution, which does not meet the environmental protection requirements and brings great insecurity in use. Polyester polyurethane ink is developing rapidly because of its many modified varieties, wide application range, good temperature and water resistance, high printing gloss and low toxicity. It is gradually accelerating the pace of replacing chlorinated polypropylene ink. Although alcohol soluble inks are rarely used at present, their growth rate is also accelerating. More and more enterprises use alcohol soluble inks in combination with two-component polyurethane adhesives to reduce the use and emission of toluene

packaging enterprises should ensure the safety of food from the technical source. The environmental protection evaluation of benzene free ink basically achieves non-toxic and harmless. From the perspective of food safety technology, it should be said to be a development direction

at present, there are more and more kinds of green food on the market, but many green food do not use green packaging. Green packaging should use environmentally friendly packaging materials, printing inks and adhesives. The 21st century is a century of environmental protection. Environmental problems are becoming more and more important, and resources and energy are becoming more and more tense. Building a circular economy society and taking the path of sustainable development has become the focus and urgent task of global attention, and has become the criterion for the development of all walks of life and human activities. With the rapid growth of China's packaging industry, we should pay attention to hygiene and environmental protection, actively promote benzene free printing technology for healthy packaging, improve the overall technical level of the food packaging industry, reduce the impact of harmful substances in packaging on consumers' health and ecological environment, and let consumers rest assured about the food itself and have confidence in the health status of food packaging, which requires the joint efforts of the whole society

source: China Packaging News

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