Application status of synthetic adhesives in packa

Application status of synthetic adhesives in packaging and printing industry in China at present, there are more than 1500 adhesive production enterprises in China, with more than 3000 varieties, which has become one of the fastest-growing key industries in the field of chemical industry in China. Synthetic adhesive has a wide range of applications and outstanding advantages of using this material, including excellent mechanical properties, high mobility, outstanding color stability, excellent chemical resistance, simplicity, high economic benefits, rapid development and many other characteristics. With the development of economy and science and technology, it will be paid more and more attention by people and become an industry with great development prospects. In China, large-scale production began in 1958, and the development of adhesives reached a climax in the 1980s. However, the synthetic adhesive industry in developed countries in the world has entered a highly developed stage, with an average growth rate of about 3% in the 1990s and 19.5% in China. In 1998, the global sales volume of synthetic adhesives was about $25billion, of which the United States accounted for about 35% of global sales, Western Europe for 25%, Japan for 15%, and China for only 7%. The global consumption structure of synthetic adhesives is that the packaging industry accounts for 35%, the construction industry accounts for 25%, the wood processing industry accounts for 20%, the automobile transportation industry accounts for 10%, and others account for 10%

from the application structure of adhesives, it can be seen that the packaging industry is the largest industry in the application of adhesives. It is widely distributed in various fields of the packaging industry, such as paper products, printing and decoration, plastics, etc. at the same time, with the development of the adhesive industry, it also improves the quality and grade of packaging products, and promotes the development of the packaging industry

I. cartons and cartons

the production industry of cartons and cartons is the industry with the largest amount of adhesive in China. At present, there are more than 15000 carton and carton production enterprises in China. When producing cartons and cartons at the beginning, foam alkali adhesive was used. As the foamed alkali adhesive is easy to regain moisture, pan alkali, low bonding strength, and the cartons and cartons bonded with it are easy to deform and change color, the use of it has been banned by the state as early as 1985, requiring the use of starch adhesive or other binding agents with the same effect

at present, except for the low-grade boxes that use foamed alkali adhesive, the automatic production lines of medium and high-grade cartons and cartons have all used starch adhesive or other equivalent extruders as the adhesive of important processing equipment. Starch adhesive production technology is also constantly updated and developed, from heating production in the 1980s to cold water production now; From the earliest colloid (liquid) to various types of solid rubber powder, the improvement of adhesive production technology has greatly facilitated the production of cartons and cartons, so that the drying speed of cartons and cartons has developed from more than 40 hours to more than 1 hour now, and can enter the next process. At first, starch adhesive was only used in the production of high-grade cartons, but now it can be used in the production of various grades of cartons. The progress of non coagulant starch adhesive technology has played a key role in the development of China's carton and carton industry

II. Packaging and printing

in order to achieve the purpose of beautifying the packaging, film covering should be carried out on the packaging printed matter. On the premise of not changing the original tone of the printed matter, the film covering can increase the gloss and make it more dazzling, and can prevent moisture, dirt, wear, etc., so as to effectively protect the inner layer. Adhesives for film covering and film covering industry are also developing. Solvent based or lotion adhesives such as e-va, polyurethane, polyacrylate, rubber, polyester, etc. are usually used, while solvent based film covering adhesives are organic solvent based adhesives. The solvents used are generally toluene, ethyl acetate, solvent oil, etc., accounting for more than 60% of the total adhesives. Therefore, in the process of operation, they not only pollute the environment and endanger the health of workers, It may also cause fire. With the attention paid to environmental protection at home and abroad, printing enterprises are urged to choose adhesives that can meet both quality requirements and environmental requirements

water based paper plastic composite adhesive takes water as the medium, and has the characteristics of strong adhesion, non-toxic, odorless, non combustion, no three wastes, safe use, high transparency and gloss. In addition, it is safe to use, no damage to workers' bodies, and no pollution to the environment. Therefore, it is deeply welcomed by the printing industry. At present, it has been widely used in packaging and printing, book printing and other fields

III. The production and application of pressure-sensitive adhesive and pressure-sensitive tape have also made great progress recently. In 1996, the market sales of adhesive tape in China reached 2.26 billion m2, most of which were packaging tapes (accounting for 2 billion m2). Since the 1990s, the production technology of domestic pressure-sensitive adhesives has gradually developed in a comprehensive direction. The United States, Japan and other countries have successively established wholly-owned or joint ventures in China, which has promoted the improvement of the technical level of pressure-sensitive adhesive products in China to a certain extent. For example, in the production of double-sided tape, acrylate soft monomer solution copolymer resin has been authorized by Alcoa, and pressure-sensitive adhesives and products with excellent performance have been prepared in the form of cross-linking other than various cross-linking agents; For another example, in the development of applicable materials: hot melt pressure-sensitive adhesive products such as metal and non-metal materials, as well as radiation curing pressure-sensitive adhesive, foreign advanced technology has also been used for reference, and now many enterprises can produce them on a large scale

the development and production of high-performance special pressure-sensitive adhesives in China, such as protective tapes with high adhesive strength for automobiles, tapes with strong adhesive properties for lifting and reuse, and special tapes with high temperature resistance and high insulation, need to be further studied and improved

in addition to the above types of adhesives, other packaging adhesives in China, such as label label, paper plastic sealing adhesive, cigarette adhesive and paper tube adhesive, should also be constantly updated with the requirements of the development of various production technologies

although China has achieved remarkable development in packaging adhesives in the past decade, there is still a certain gap with the world advanced level in many aspects, mainly including: the variety and quality can not fully meet the requirements, and many varieties still need to be imported; The research of applied technology cannot catch up with the development requirements of new varieties; The production equipment is backward, and there are many low-level duplicate varieties. At present, there is no systematic national and industrial materials and testing means