At present, the adhesives used in the flexible packaging industry include one-component polyurethane adhesives, two-component polyurethane adhesives, acrylic adhesives, solvent-free adhesives, alcohol-soluble, water-soluble polyurethane adhesives, and the like.
The development of China's flexible packaging industry is closely linked with the technical progress of domestic two-component polyurethane adhesives. At present, the domestic production capacity of two-component polyurethane adhesives for flexible packaging is nearly 50,000 tons, ordinary adhesives and some functions. The adhesive can already be fully domesticated. 75% solids two-component polyurethane adhesives occupy 60% of the market share, and the market for 50% solids two-component polyurethane adhesives is shrinking, but it still occupies more than 30% of the share, less than 10% of special In the adhesive market, imported adhesives still have an advantage. Domestic adhesive companies have matured and their technological development capabilities have been greatly enhanced. Their products have become functional and have occupied more than 80% of the domestic market share. The market competition has also shifted to a meager and orderly stage. There have appeared markets such as Beijing Gaomeng Chemical Co., Ltd., Beijing Chemical Industry Research Institute, Zhejiang New Oriental Ink Group Co., Ltd., Guangdong Zhongshan Kanghe Chemical Co., Ltd., and Jiangsu Jintan Adhesive Factory. On the leading companies, these companies have the ability to develop and produce functional adhesives themselves and have been validated in the market.
China's flexible packaging materials are mainly based on dry composites. The rapid development of dry composite materials has brought about tremendous changes in the packaging industry, and has obtained huge economic and social effects. The two-component polyurethane adhesive used in this composite process is mature and low-cost. Its disadvantage is that it emits a large amount of solvent to pollute the environment. In addition, during the compounding process, trace amount of residual solvent remains in the substrate. It will produce odors in the packaging. Environment and development have become major issues of concern in the world today. Countries have set off a revolution to protect the environment and reduce pollution. Under this background, traditional polyurethane adhesives have been challenged unprecedentedly, and foreign companies are also sticking to environmental protection. The mixture has attracted the Chinese market, and domestic forward companies have also conducted extremely meaningful explorations of environmentally friendly adhesives. For a long period of time, polyurethane adhesives will still occupy most of the market share in China, and the use of solvent-free adhesives will increase significantly in the short term, but it will not develop much.
The reason for this is that in addition to the current non-solvent adhesives, alcohol-soluble, water-soluble and other products whose performance, price, or equipment investment costs are inferior to the existing two-component polyurethane adhesives, domestic production of base film materials and equipment conditions, It is still not fully satisfied with the application requirements of alcohols, water-based adhesives, and drying requirements. China's actual national conditions are also a reason that cannot be overlooked. At present, China has introduced more than 30 solvent-free production lines, most of which are still in production and semi-discontinued. State, companies with solvent-free production lines are working hard to transfer some products to solvent-free equipment, which will expand the application of solvent-free adhesives, but expensive equipment investment will be overwhelming for companies. In recent years, there have been no domestic The introduction of solvent production lines has significantly weakened.
Soft packaging companies and adhesive production companies cannot blindly catch up with the new wave. They must build on the basis of national conditions and seeking truth from facts, and find a new path for the smooth and healthy development of China's flexible packaging industry so that environmental resources can be effectively protected. Effectively solve some environmental problems that are currently urgently needed to solve and have the ability to solve, such as: Do not use one-component polyurethane adhesives, eliminate toluene emissions, reduce the use of 50% adhesives, increase the concentration of coating work, and further reduce B Ester volatilization. Domestic high-concentration working concentration coating technology is not very good grasp, the general business is best to only achieve 35% coating, and in addition to high transparency requirements of products, polyurethane adhesives can generally increase the working concentration to 40 % to 45%, which is very significant for reducing the volatilization of ethyl ester, protecting the environment and reducing costs. Adhesive companies must work closely with equipment manufacturers and roller manufacturers to help composite companies improve coating technology. Adhesive companies should focus on the development of water-based, solvent-free adhesives. Alcohol-soluble adhesives are just excessive products. It is not an environmentally friendly product in the true sense. Its application is limited, and its application volume in the foreign flexible packaging market is also very small. Domestic adhesive manufacturers should use the advantages of two-component polyurethane adhesives, concentrate their efforts on the development of functional blends, and expand their market space.
The most recent functional adhesives that have been successfully introduced on the market today are: 1. Fast-curing adhesives. Generally after the two-component adhesive is compounded, it should be placed in an environment of about 50 degrees for more than 48 hours, and then it can be taken out to cut and cut the bag, which reduces the production efficiency and does not meet the fierce market competition requirements. Fast-curing adhesives can be slit as long as they are placed in an environment of about 50 degrees for 4 to 8 hours. However, due to the defect of decreased strength after aging, the composite film becomes brittle and has not yet entered the market. The rapid curing station mixture is In 2000, it really took the market. 2, anti-chemical media erosion adhesive. In this regard, Henkel Corporation still occupies a large advantage, especially in the packaging of liquid pesticides, it is understood that in the food and cosmetics, domestic adhesives have been able to provide acid, alkali, salt, anti-pungent, oil , Aromatic, Surfactant Resistant Adhesive. 3. Adhesive with high additive content film composite. With the wide application of composite flexible packaging, the requirements for packaging materials have become more and more diversified, and various functional auxiliaries have been added to the manufacture of thin films. However, the addition of a large amount of functional auxiliaries has brought new problems. The adhesive cannot meet the requirements for composite strength. After aging with ordinary adhesives, the strength drop is very obvious and can not even be used. In addition, the development of dry composite radiation or UV curing polyurethane batches is also a hot spot in the future.