The valve bag is a type of packaging bag that sets the valve port on the top or bottom of the bag into the material filling port of the valve bag filling machine to achieve high-speed quantitative filling. It uses a variety of different types of valve ports to adapt to various types of valve bag filling machines and types of packaging products. The high-strength kraft paper or paper-plastic composite cloth has high firmness and strong impact resistance. After being filled with materials, it automatically fills up the cuboid, which is convenient for stacking neatly. It is suitable for the packaging of granular, powder and ultra-fine powder materials. It is currently international The widely used environmentally friendly packaging bag type is especially suitable for export enterprises. Valve pockets are mainly used for packaging powdery or granular solid materials and flexible articles such as edible powder, chemical powder, fertilizer, synthetic materials, explosives, grain, salt, minerals, etc.