Environmental protection and safety problems of th

2022-08-24
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Environmental protection and safety issues of composite packaging adhesives

various factors should be considered in the selection of adhesives for food flexible packaging. Generally speaking, the following conditions should be met:

(1) non toxic; (2) There is no harmful extract after packaging food; (3) Applicable temperature requirements for food storage; (4) Good weather resistance, no yellowing and blistering, no pulverization and delamination; (5) Have certain medium resistance; (6) It does not erode the printing pattern ink, and has a high affinity for the ink

the adhesive for packaging composite film should also have the following properties:

(1) adhesion: the adhesive must have the performance of bonding two different materials at the same time

(2) softness: it can meet the needs of settling and expansion of meimeike for flexible transportation and storage after compounding

(3) heat resistance: according to the food post-processing technology, there is a manufacturing technology level and overall strength to further improve the heat resistance

(4) cold resistance: it can meet the requirements of low-temperature storage of food

(5) medium resistance: the stability of the adhesive is very important. It should be able to withstand the erosion of the medium, otherwise it will cause the delamination and peeling of the composite film and lose its packaging function

(6) safety and hygiene: meet the requirements of relevant standards for food packaging safety and hygiene

nbsp; China has long had laws and regulations and corresponding health standards for food and its packaging materials, including two: the food hygiene law of the people's Republic of China and the measures for the administration of plastic products and raw materials for food. The food hygiene law was promulgated by the State Council, while the administrative measures was promulgated by the Ministry of health. These two are mandatory laws, and those who violate their provisions will be liable to the law. The content of food hygiene regulations is much broader than the management methods, and it is a comprehensive law. The latter is professional, which only refers to plastic products and raw materials, and the scope of management is limited to all kinds of plastic tableware in contact with food? Container? Production management, packaging materials made of conveyor belts and plastics, and synthetic resins and additives used

there are two main series of substitutes for solvent based adhesives at present

first, water-based adhesives. The advantages of water-based adhesives are: the viscosity does not change significantly with the molecular weight of the polymer, so the polymer can be quantified to improve its cohesive strength; Viscosity is generally lower than that of solvent type; Easy to mix with other resins or pigments to improve performance? Reduce costs; Incombustible? Non toxic, suitable for substrates easily eroded by organic solvents; It is easy to prepare formula and clean up

aqueous adhesives mainly include two product series: one component and two component. The single component series is characterized by direct use without proportioning, simple operation process, low cost and high production efficiency. The advantages are more prominent in the composite properties of the film and the aluminized film, which will not cause the transfer of the aluminized film like polyurethane glue. Due to the limitation of peel strength, one component aqueous adhesives are mainly used in puffed food? biscuit Candy? Light packaging fields such as condiments and drugs. And the two-component aqueous adhesive breaks through the peel strength? Technical problems such as heat resistance and chemical resistance can be used in the packaging of cooked food and liquid food

second, solvent-free adhesives. Solvent free adhesives are basically composed of two-component polyurethane adhesives. Their main agent and curing agent have high viscosity at room temperature, but they still have fluidity and are semi-solid substances. When compounding, the main agent and curing agent are mixed in proportion, put into the adhesive tray with heating and insulation function, reduce the viscosity to an appropriate level by heating, and then apply it to the substrate through the corrugated roller with heating and insulation function. After coating, it can be directly compounded with another substrate without heating and drying

Rohm & Haas is a multinational company that takes the lead in promoting water-based composite adhesives in China's flexible packaging market, and is also the first enterprise to commercialize the supply of water-based adhesives in the Chinese market. Rohm & Haas believes that the European and American flexible packaging markets currently mainly use water-based and solvent-free series, and the development direction of China's flexible packaging market is undoubtedly more environmentally friendly and hygienic. Rohm & Haas helps customers calmly deal with future regulations

at present, Rohm & Haas has accounted for about 90% of the water-based adhesive market in the global flexible packaging industry. The water-based adhesives of Rohm & Haas company in the United States mainly include two product series: one component and two component. One component water-based adhesives are mainly used in puffed food? biscuit Candy? Condiments and other light packaging fields. And the two-component aqueous adhesive breaks through the peel strength? Technical problems such as heat resistance and chemical resistance can be made into high-end products such as cooked food and liquid packaging. The adhesive layer of waterborne acrylic adhesive is soft and tough, especially suitable for manufacturing various laminated composite films for food packaging. Domestic (3) many well-known egg yolk pie producers of food related products? biscuit instant noodles? oatmeal? Soymilk brands even designated their packaging manufacturers to use the water-based adhesives produced by Rohm and Haas. The support of end users accelerated the promotion of water-based adhesives in China

Rohm & Haas is more committed to promoting the development of the whole industrial chain towards high efficiency, energy conservation, safety and environmental protection. Through technical support and exchanges with food manufacturers, they will recognize new environmentally friendly packaging, so as to promote the normal and healthy development of the industrial chain. At the same time, Rohm and Haas has always paid attention to the environment, the voice of the community and consumers, advocated appropriate packaging and green packaging in the industry, advocated that packaging should take practical environmental protection and safety and health as the main consideration, and pay attention to environmental protection and other societies

Rohm & Haas is the world's largest manufacturer of acrylic lotion, and has invested in the construction of two acrylic lotion production plants in Beijing and Shanghai, China. Rohm & Haas introduced the mature environmental friendly water-based adhesive in the U.S. market. It does not contain organic solvents, and its performance can fully meet the film and film used in ordinary food packaging? The dry compounding between the film and the aluminized film requires that it can replace the solvent based polyurethane adhesive and can be directly used on the existing solvent based dryers. The raw materials of Rohm and Haas adhesives, such as monomers and intermediates, are produced and synthesized by Rohm and Haas. The strong supply chain ensures the stability of raw materials. Rohm and Haas advanced production technology and full grip screw force automation equipment make it produce water-based adhesives that occupy a leading position in the world. In addition, this water glue composite packaging film can be cut immediately without aging, so it can reduce the production cycle for color printing manufacturers, especially in the peak season, and can calmly deal with the emergency orders of food manufacturers

reprinted from: China Packaging News

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