This type of machine is suitable for processing natural or colored flat bags made of cylindrical plastic films such as HDPE films, LDPE films and so on (applicable to medicine bags, vacuum bags, etc.) The feature of this machine is to reduce the stretch of the bag sealing during operation. This machine can process film bags with a welding width of 1-15mm, and increase the welding strength of the bags. Computer-controlled servo motor structure. (Three servo motors) The servo motor-controlled flying cutter structure takes the place of up-down cutter structure. The up-down movement of welding knife is controlled by a servo motor (optional). The electric eye tracks the color mark of color printing film, making the position of words and pictures more accurately. The length and production speed of bag are controlled by the computer, which makes less waste and easier operation. This machine has many automatic functions, such as feeding, sealing and cutting, counting, dischargi