The mechanical part of the packaging scale is mainly composed of a storage hopper, large and small spirals, a weighing hopper, a material discharge transition bin, and a bag clamp; the electrical control part is composed of a weighing sensor, a weighing display instrument, a PLC, a bag clamp switch, a solenoid valve, and a frequency converter. Improper operation of the packaging scale may cause the quantitative packaging scale to malfunction. So what are the reasons for the failure of the packaging scale and how to deal with it when it occurs?

(1) No bag clamping and no material discharge, usually due to problems with the bag clamp switch, bag discharge switch, or solenoid valve or cylinder that controls the bag clamp.

(2) The large and small material cutting doors and the weighing hopper discharge door cannot be opened or closed, usually due to problems with the control solenoid valve or cylinder.

(3) After the material is weighed, the material door cannot be opened automatically to discharge the material and loosen the bag. If the manual discharge button is pressed, it does not work. Generally, there is a problem with the solenoid valve or cylinder that controls the material door. It will return to normal after replacing the spare parts. If the manual discharge button is pressed, it means that the weighing is out of tolerance or the system parameter setting is wrong.

(4) Material leakage from the weighing bucket or bag clamping port is usually caused by poor sealing of the scale body, insufficient air pressure (check that the air source is greater than 0.4MP), solenoid valve or cylinder problems.

(5) Inaccurate measurement and unstable instrument display. It may be that the instrument zero point drifts (calibrate with standard weights) or the parameter setting needs to be re-corrected, or the weighing sensor fails (replace the sensor and use weights for calibration).

(6) When the system cannot discharge the material normally, set the selection switch to manual, and then press the discharge button for more than 3s, and the corresponding packaging scale can return to normal after the initialization operation.