Airless pressurized filling with pre-formed bags is a popular form of packing in the international packing industry. It is characterized by its novel shape, varying design, reliable measurement, firm sealing, simple operation and low cost for packing materials. It is widely used in the airless packing of dairy (milk, yogurt and lactic drinks, etc.), soybean products (Japanese bean curd, etc.), condiments (soy, cooking oil, etc.), beverage, ice-cream, mineralized water, detergent, wine, etc. to avoid secondary contamination.