The mechanical part of the packaging scale mainly consists of a storage hopper, a large and small spiral, a weighing hopper, a discharge transition bin, and a bag clamp; The electrical control part consists of a weighing sensor, a weighing display instrument, a PLC, a bag clamp switch, an electromagnetic valve, and a frequency converter.


Improper operation of packaging scales can cause malfunctions in quantitative packaging scales. So, what are the reasons that can cause packaging scales to malfunction and what should be done when malfunctions occur?


(1) Not clamping bags, not discharging materials, usually due to issues with the bag clamping switch, bag releasing switch, electromagnetic valve or cylinder controlling the bag clamping.


(2) The inability to open or close the cutting and discharging doors, as well as the weighing and discharging doors, is usually caused by issues with the control solenoid valve or cylinder.


(3) After the material weighing is completed, it is not possible to automatically open the material door to discharge and loosen the bag. If the manual discharge button is pressed, it is also not possible. Generally, there is a problem with the electromagnetic valve or cylinder that controls the material door. After replacing the spare parts, it will return to normal. If pressing the manual feeding button is feasible, it indicates that the weighing is out of tolerance or the system parameter settings are incorrect.


(4) Leakage from the weighing bucket or bag opening is usually caused by inadequate sealing of the scale body, insufficient air pressure (check if the air source is greater than 0.4MP), electromagnetic valve or cylinder issues.


(5) Inaccurate measurement and unstable instrument display. It may be due to zero drift of the instrument (calibrated with standard weights) or the need for parameter settings to be corrected, or a malfunction of the weighing sensor (replacing the sensor and nominal with weights).

(6) When the system cannot discharge materials normally, set the selection switch to manual, and then press the discharge button for more than 3 seconds. After the corresponding packaging scale initialization operation, it can be restored to normal.