Core principle: Heated hot knife completes sealing and cutting in one single action.
Roll film goes through unwinding, tension control and web guiding. Photoelectric sensor tracks color mark to fix bag length. When film reaches the preset position, the heated knife presses down. High temperature partially melts the plastic film. It bonds the film (sealing) and cuts off the web at the same time. After cooling, the cut edge fuses together automatically.
PLC and servo system synchronize knife movement and feeding. Temperature is a critical parameter. Overheat causes film burn-through and yellowing; insufficient temperature leads to incomplete cutting and weak seals.
Core principle: Separate stations for sealing and cutting. Heat seal first, then cut by unheated mechanical knife. The cutter itself has no heating.
Film unwinds, tension adjusted, web corrected and positioned by photoelectric eye. First, an independent heat sealing bar heats and bonds the film to form the bag bottom seal (seal only, no cutting). The film moves forward to cold cutting station. The ambient upper & lower flying scissors cut the film by pure mechanical shearing force.
Cutting is just physical separation. No melting occurs, so the cut edge remains open. Servo flying cut mechanism follows the running film synchronously while feeding continues, realizing continuous production.
