The management of food packaging must be strengthe

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We must strengthen the management of food packaging

printing ink is one of the factors that cause hygienic quality problems in food packaging. Many food packages are printed with colorful exquisite patterns. However, most printing inks contain benzene, which is harmful to human body. In order to quickly print thick ink on the plastic film used for food packaging, enterprises need to add a mixed solvent to the ink to dilute and promote drying when producing packaging bags. Because the ink itself in the ink system currently used in China contains benzene, it can only be diluted with a mixed solvent containing toluene. At present, the purity and price of toluene on the market vary a lot due to different extraction sources. If enterprises use low-cost toluene with low purity when producing food packaging bags, the problem of benzene residue will be more serious. Toluene, butanone, ethyl acetate, isopropanol, etc. are the basic raw materials for mixing solvents. Excessive residue of these materials will undoubtedly affect the safety of packaged food

most relevant enterprises know the harm of benzene residue very well, but the methods of controlling benzene residue vary greatly among enterprises. For example, large-scale enterprises usually use high-speed printing equipment and powerful air supply and exhaust systems to reduce benzene residues, but such equipment can only be equipped with investment of millions or even tens of millions of yuan. In addition to adding exhaust fans in the workshop, small enterprises with relatively simple equipment can only reduce the residue of benzene by baking in such a high-temperature curing workshop

because benzene will appear in ink diluents and adhesives, if the manufacturer does not leave enough time for benzene to volatilize in the production process, benzene will continue to remain in the finished products, and if it exceeds a certain amount, it will pose a threat to human health

organic solvents can dissolve many natural and synthetic resins and are important components of various inks. Some of these ingredients will damage the human body and subcutaneous fat, and long-term contact will make the skin dry and rough. If it penetrates into the skin or blood vessels, it will endanger human blood cells and hematopoietic function with the blood. Being sucked into the trachea, bronchus, lungs or transmitted to other organs through blood vessels and lymphatic vessels may even cause the body to slowly pass through the efforts of all parties. The toxicity of some inks containing heavy metal ions. Pigments and dyes contain carcinogenic ingredients, which are very harmful to human health

a large number of inks, organic solvents and adhesives are used in the printing of composite packaging materials. Although these auxiliary materials have no direct contact with food, some toxic substances will migrate into food during the process of food packaging and storage, endangering people's health. Ethanol, isopropanol, butanol, propanol, butanone, ethyl acetate, butyl acetate, toluene, xylene and other organic solvents are often used in printing inks. Influence of eccentricity: the load borne by the card end produces uneven stress distribution on the end section. Although most of these solvents can be removed by drying, the residual solvents will migrate to food and endanger human body

benzene is an aromatic hydrocarbon, which is the product of coal tar distillation or petroleum cracking. Benzene can cause chronic poisoning, which mainly improves the large-scale production capacity and has more advantages in price, causing damage to the nervous system and hematopoietic system, manifested as headache, dizziness, insomnia, continuous leucopenia, thrombocytopenia and bleeding tendency. These damages occur slowly, will not appear in the short term, and are easy to be ignored by consumers. Therefore, ink can not be in direct contact with food. Now most food packaging bags are printed in this way: after printing the pattern on the plastic bag, attach a layer of plastic on it, even if the ink is enclosed between the two layers of plastic, so it will not easily pollute the food. But consumers still need to be vigilant. Plastic bags that can wipe the patterns off by hand are unqualified. Benzene is a highly volatile substance, which is easily released into the atmosphere during the printing process and pollutes the environment

gravure inks use more VOC as solvent. Long term exposure to high concentrations of VOC will cause great damage to the human body, especially the nervous system. VOC also has photochemical reaction with nitrogen oxides in the air, producing ozone and smoke. At present, the gravure printing technology in China has a strong distribution capacity because its printing ink contains formaldehyde, which is harmful to human body, but it has not been banned yet. At present, there may be only two layers of plastic between some pickled foods and the harmful chemical formaldehyde

since most flexible packaging materials are composite materials, glue must be used in composite materials. There are many impurities in aromatic and aliphatic glue. In the process of food manufacturing, high-temperature cooking environment is often encountered. In these cases, these harmful substances will dissociate, form harmful substances GDI (isocyanate) and penetrate into food

Europe and the United States and other countries have not allowed the use of raw materials containing benzene and heavy metals in food packaging, and the Japanese government has stipulated three years ago that benzene should not be contained in food packaging materials. At present, China has only made requirements for the inner packaging of food, but only recommended standards. The national standard gb/t10005-1998 implemented on February 1st, 1999 stipulates that the total amount of solvent residues in composite membranes and bags is ≤ 10mg/㎡, including benzene solvents ≤ 3.0mg/㎡. As for the outer packaging of food, its supervision is limited to the size, appearance, strength and indoor mechanical properties, and rarely involves harmful substances such as solvent residues

there is no mandatory standard, no effective supervision, no unified blending process, and no specific restrictive measures. These factors lead to a common phenomenon that a residue in the products of enterprises exceeds the standard. At present, the national ink Standardization Technical Committee has reported to the relevant national departments and is preparing to draft two mandatory standards to regulate the residue limits of ink solvents in food packaging

source: Chinese ink technology

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