The valve packing bag puts forward higher requirements for the high precision intelligent high speed level of packaging machinery.

Valve pockets can be divided into pp valve pockets, PE valve pockets, paper-plastic composite valve pockets, kraft paper valve pockets and multi-layer kraft paper valve pockets. The PP valve pocket is made of polypropylene braided cloth on the valve port or the lower valve port, which can improve the packaging efficiency than the general PP woven bag; PE valve pocket is made of polyethylene braided valve port; The paper-plastic composite valve pocket is made of plastic woven bag (referred to as cloth) as the base material and is made by the streamline composite method (cloth/film composite is two-in-one, cloth/film/paper composite is three-in-one); The material of the kraft paper valve pocket is mainly kraft paper, which is divided into imported kraft paper and domestic kraft paper. Valve pockets can be divided into: upper open valve pockets, lower open valve pockets, upper and lower open valve pockets. The valve pocket is mainly used for packaging food powder, chemical powder, fertilizer, synthetic materials, explosives, food, salt, minerals and other powdered or granular solid materials and flexible items. Especially suitable for export enterprises to use, can improve the packaging grade of products. With the rapid development of China's economy, the purchasing power level and consumption willingness of domestic residents have gradually increased, and the consumption concept will tend to further improve the quality of life. The market demand for liquid food such as beverages, alcohol, cooking oil and condiments will also grow steadily with the development of the economy and the improvement of people's living standards. In the long run, China's liquid food industry such as beverages, alcohol, cooking oil and condiments still has a large room for growth, especially the improvement of consumption power in rural areas will greatly stimulate the consumption of liquid food such as beverages. In short, the rapid development of the downstream industry and people's pursuit of quality of life, will inevitably require enterprises to invest in the corresponding packaging equipment to meet the needs of production, but also the high precision, intelligent, high-speed level of packaging machinery put forward higher requirements, so China's liquid food packaging machinery will show a broader market prospects. Composite flexible packaging materials can be used only when they are finally made into various packaging bags. There are two ways to make bags, one is that the packaging manufacturers use the roll film in the automatic packaging machine filling, and molding packaging into a variety of bags; The other is due to the bag-making mechanism into various bags and then fill the contents. Due to the precise control of professional bag making, beautiful bag shape, large bag making changes, and many bag types, therefore, in quite a few cases, bags are made first. The main varieties of bags are: three-side sealing bag (palm sealing bag), back sealing bag, folding tip (organ bag), upright bag and so on.