The working process of the food vacuum packaging machine can be roughly divided into four parts:
1. Vacuum
The vacuum chamber is closed, the vacuum pump works, the vacuum chamber starts to evacuate, the packaging bag is vacuumed at the same time, the vacuum gauge pointer rises, and the rated vacuum degree is reached (controlled by the time relay ISJ). The vacuum pump stops working and the vacuum stops. While the vacuum is working, the two-position three-way solenoid valve IDT works, the heat sealing air chamber is vacuumed, and the heat pressing frame remains in place.
2. Heat sealing
IDT is disconnected, the outside atmosphere enters the heat sealing air chamber through its upper air inlet hole, and the heat sealing air chamber is inflated by the pressure difference between the vacuum chamber and the heat sealing air chamber, so that the upper heat pressing frame moves down and presses the bag mouth; at the same time, the heat sealing transformer works and starts sealing; at the same time, the time relay 2SJ works, and it acts after a few seconds, and the heat sealing ends.
3. Return air
The two-position two-way solenoid valve 2DT is open, the atmosphere enters the vacuum chamber, the vacuum gauge pointer returns to zero, the heat pressing frame is reset by the reset spring, and the vacuum chamber is opened.
4. Cycle
Move the above vacuum chamber to another vacuum chamber, and then enter the next working process. The left and right chambers work alternately, and the cycle repeats.