At present, my country has more than 1,500 adhesive manufacturers with more than 3,000 varieties, which has become one of the fastest-growing key industries in my country's chemical industry. Synthetic adhesives have many characteristics such as wide application, easy use, high economic benefits, and rapid development. With the development of economy and technological progress, it will attract more and more people's attention and become an industry with great development prospects. In my country, large-scale production began in 1958. In the 1980s, the development of adhesives reached a climax. However, the synthetic adhesive industry in developed countries in the world has entered a highly developed stage. The average growth rate in the 1990s was about 3%, and the average growth rate in my country was 19.5%. In 1998, the global sales of synthetic adhesives were about 25 billion US dollars, of which the United States accounted for about 35% of global sales, Western Europe accounted for 25%, Japan accounted for 15%, and my country accounted for only 7%. The global synthetic adhesive consumption structure is 35% for the packaging industry, 25% for the construction industry, 20% for the wood processing industry, 10% for the automobile transportation industry, and 10% for the others.
It can be seen from the adhesive application structure that the packaging industry is the largest industry in which adhesives are applied. It is widely distributed in various fields of the packaging industry such as paper products, printing and decoration, and plastics. Quality and grade have promoted the development of the packaging industry.
1. For carton and carton
The carton and carton production industry is the industry with the largest amount of adhesives in my country. At present, there are more than 15,000 carton and carton manufacturers in my country. In the initial production of carton and carton, Paohua alkali adhesive is used. Because the Paohua alkali adhesive is easy to return moisture, efflorescence, low bonding strength, and the cartons and cartons bonded with it are easily deformed and discolored, so as early as 1985, the state has explicitly banned the use, requiring the use of starch adhesive instead. agent or other binding agent of equivalent effect.
At present, in addition to the low-grade box using phenolic caustic soda binder, the automatic production lines of medium and high-grade carton boxes and carton boxes have all used starch binder or other binders with the same effect. 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 development of adhesive production technology. The improvement greatly facilitates the production of cartons and cartons, so that the drying speed of cartons and cartons from the original more than 40 hours to the current more than one hour can enter the next process. At first, starch adhesive was only used for the production of high-grade cartons, but now it can be used to produce various grades of cartons. The advancement of non-gelling starch adhesive technology has played a key role in the development of my country's carton and carton industry.
2. Packaging and printing
In order to achieve the purpose of beautifying the packaging, lamination should be carried out on the packaging printed matter. The lamination can increase the gloss and make it more eye-catching without changing the original tone of the printed matter, and can prevent moisture, stains, wear, etc., Thereby effectively protecting the inner layer. The adhesives for lamination and the lamination industry are also developing continuously. Usually, solvent-based or emulsion-based adhesives such as E-VA, polyurethane, polyacrylate, rubber, polyester, etc. are used. The adhesive is an organic solvent-based adhesive. The solvents used are generally toluene, ethyl acetate, solvent oil, etc., accounting for more than 60% of the total adhesive. Therefore, during operation, it not only pollutes the environment, endangers the health of workers, but also may cause fire. , With the emphasis on environmental protection at home and abroad, printing companies are prompted to choose adhesives that can meet both quality and environmental requirements.
The water-based paper-plastic composite adhesive uses water as the medium, and has the characteristics of strong adhesion, non-toxic, odorless, non-flammable, no three-waste pollution, safe to use, high transparency and gloss, plus it is safe to use and is safe for workers. No damage, no pollution to the environment, so it is very popular in the printing industry, and it has been widely used in packaging printing, book printing and other fields.
3. Pressure-sensitive adhesive and pressure-sensitive tape
The production and application of pressure-sensitive adhesives and pressure-sensitive tapes have also developed significantly recently. In 1996, my country's market sales of tapes reached 2.26 billion m2, most of which were packaging tapes (accounting for 2 billion m2). After entering 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 my country, which to a certain extent has promoted the technological level of pressure-sensitive adhesive products in my country. improve. For example, in the production of double-sided tape, it has been possible to use acrylate soft monomer solution to copolymerize resin, and use various cross-linking agents to obtain pressure-sensitive adhesives and products with excellent performance in the form of cross-linking; another example, in the development of hot melt In terms of pressure-sensitive adhesive products and radiation-cured pressure-sensitive adhesives, foreign advanced technology has also been used for reference, and many enterprises can now produce them on a large scale.
In the development and production of high-performance special pressure-sensitive adhesives in my country, such as protective tapes with high bonding strength for automobiles, tapes with strong adhesion properties for lifting, and special tapes with high temperature resistance and high insulation, further research is needed and needs to be improved.
In addition to the above types of adhesives, other packaging adhesives in my country, such as label labels, paper-plastic sealing adhesives, cigarette adhesives, and paper tube adhesives, must be constantly updated with the development of various production technologies.
Although my country's packaging adhesives have achieved remarkable development in the past ten years, there is still a certain gap with the world's advanced level in many aspects, mainly including: varieties and quality can not fully meet the requirements, many varieties still need to be imported; application technology research work It cannot keep up with the development requirements of new varieties; the production equipment is outdated, there are still many low-level repeated varieties, and there is currently no systematic country, industry materials and testing methods.