In foot sealer case, user has to put the pedal to press a heating bar with a pressing bar so the rod connected to pedal draws to press a heating bar, but this work may give a damage to user’s knee if an user works for long time in a day, so it is the reason why semi-auto sealer which is completed to draw a pressing bar by solenoid (electric magnetic), not by manual is developed. As it uses magnetic power, it can save the labor hour and user’s fatigue . NA (auto sealer) is upgraded item from NS because it has a timer to control pressing time of upper bar (a pressing bar). It can be controlled, drawing upper bar definitely by setting timer.
However these model have a limitation to produce a lot of sealing in a day so band sealer can solve this problem using belt. (We just put the film to the mouth of rolling belt)