Composite process comparison:
a. Production speed: Dry composite is affected by the solvent volatilization rate of the adhesive. Generally, the maximum speed is only about 100m/min. Extrusion compounding can reach 150m/min, and some extruders can reach 300m/min. 
b. Peel strength: Dry composite peel strength (plastic/plastic composite) is generally 1 ~ 3.5N/15mm, suitable for most product requirements, extrusion composite peel strength under the general process conditions (plastic / plastic composite) 0.7～1.5N/15mm, suitable for general packaging materials, products with high peeling strength must be added with thermal bonding resin, when combined with thermal bonding resin, peel strength can reach 10N/15mm, even more high. 
The combination of history and the status quo has been a 40-year history since its inception in the 60s. Especially since the 1980s, extrusion compounding has been at a rapid development stage in Europe, America, Japan and Korea. At present, extruded composites account for about 50% of flexible packaging in the United States and Europe, and 70% in Japan and South Korea. Extruded composite products cover almost all areas of packaging. Compared with advanced countries, the development level of China's extrusion compounding industry is quite different. At present, China's extruded composite products account for about 25% of flexible packaging, and most of them are low-grade instant noodle packaging.
Adhesive
At present, there are three major categories of adhesives commonly used in the flexible packaging industry: solvent-free adhesives, water-based adhesives, and solvent-based adhesives. Environmentally-friendly European and American developed countries use mainly solvent-free adhesives and water-based adhesives in the production of flexible packaging. Most flexible packaging companies in Asia and Africa still use solvent-based adhesives; solvent-based adhesives account for over 90% of the market share in Japan, where the flexible packaging industry is more developed. According to incomplete statistics, there are more than 6,000 flexible packaging manufacturers in China, and more than 95% of flexible packaging manufacturers use solvent-based adhesives. Less than 5% of companies use environmentally friendly adhesives. The use of high solids and low viscosity adhesives has become an important development direction for dry composite adhesives. Previous two-component polyurethane adhesives, whose solid content of the main agent was 35% or 50%, have now been increased to 75% or 80%. 75% solids two-component polyurethane adhesives occupy 60% market share, and the market for 50% solids two-component polyurethane adhesives is shrinking to less than 30% market share. Due to the characteristics of high solids and low viscosity, it is possible to use high solids content for high-speed composite machining.
Flexo ink
In the United States, water-based inks complying with the VOC regulations must be used in an ink composition in which the volatile matter content is below 25% and the moisture content is above 75%. In the case of inks with less moisture, the non-volatile components are above 60%. Two standards. In the United States, 95% of flexographic prints and 80% of gravure prints use ink. Flexographic printing is still in its infancy in China and currently accounts for only about 3% of the printing industry. In the flexo package printing, the vast majority of domestic and foreign water-based ink printing. From 1995 to the end of 1998, China introduced more than 130 combined flexo printing lines in more than 20 provinces and cities in the country in just a few years. There are nearly 200 narrow flexographic printing production lines in China. More than 100,000 tons.
The proportion of flexographic printing in the printing field, especially packaging printing, will gradually increase.
It is estimated that by 2010, flexographic printing will reach about 15% in the printing field, and annual demand will be over 100,000 tons of water-based ink.
Plastic film At present, the annual output of plastic packaging in China is over 2.5 million tons, among which disposable plastic packaging that is difficult to recycle accounts for 30%. The waste generated each year is about 17 million tons, and the annual waste of plastic packaging products is as much as 1 million. Ton.
Recently, according to the inspection results of the food packaging bags (films) announced by the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ), the sampling failure rate is as high as 15%. The main quality issue is that the health indicators do not meet the standards and the physical and mechanical properties of the products are poor. In food flexible packaging, plastic film accounts for 70% of the total composition, adhesives account for 10%, ink accounts for 10%, and others account for 10%.
Source: PACK.CN
