In industrial production, when the bulk bag packaging scale delivers materials, there may be slight overloading or underloading. This phenomenon is usually the result of the interplay of various factors such as equipment conditions, material properties, and external disturbances. To solve this problem, we need to conduct in-depth investigation and analysis from the following key dimensions:
I. Physical Impact of Mechanical Structure
The condition of the mechanical components is the fundamental factor causing the weight deviation.
The tension variation of the soft connection components
The soft connections (such as cloth bags or canvas tubes) between the packaging scale and the lower conveying equipment or the bags are prone to adsorb dust from the air during normal operation. When these soft connections become dirty, rough, or partially knotted, their own hanging properties and frictional resistance will change. This fluctuation in physical tension will directly interfere with the gravitational signal received by the weighing sensor, thereby causing errors.
2. The smoothness of the feeding mechanism
If the spiral feeding method is adopted, it is necessary to check whether there is any material bridging or agglomeration inside; if it is the gravity self-flow type, attention should be paid to whether the action of the pneumatic gate valve is tight. If the gate is not closed tightly, it will lead to a slight leakage of materials, and if the feeding port gets blocked, it will cause an instantaneous interruption of the flow. These two extreme situations will seriously affect the accuracy of measurement.
II. Dynamic Matching of Parameter Settings
The operating parameters of the equipment are the key software factors that determine the accuracy of material cutting.
The coordination of the fast and slow feeding logic
The packaging scale is usually set to quickly load the material to approach the target value first, and then switch to slow and accurate feeding. If the amount of premature stopping during the fast loading stage is too large, it will result in an excessive amount of material to be filled during the slow loading stage, which is very likely to cause excessive impulse. On the contrary, if the fast loading stops too early, the time for the slow loading stage is prolonged. Due to the influence of airflow or mechanical inertia, it is also prone to cause insufficient weight.
2. Calibration of the offset compensation value
At the moment of cutting off the feed source, due to mechanical inertia, there are still a few materials falling in the air. If the weight of this "airborne material column" is not properly compensated in the system, it will become a source of error. The system's drop compensation parameters need to be adjusted in a timely manner according to the fluidity of the materials.
III. Environmental Constraints on Material Characteristics
The physical state of the packaged materials directly restricts the measurement process.
Interference from humidity and static electricity
Changes in environmental humidity can affect the repose angle and adhesion properties of powder or granular materials. An overly dry environment is prone to generating static electricity, causing the materials to adhere to the pipe walls or hopper walls and fail to fall; while an excessively high humidity may cause the materials to aggregate into lumps, resulting in intermittent and uneven discharging.
2. The effect of air-filled agitation
For certain specific materials, the packaging scale system is equipped with an inflation-assisted flow device. If the air source pressure is unstable or the distributor gets clogged, it will result in insufficient fluidization of the material, causing "mouse holes" or "bridging" phenomena, thereby disrupting the uniformity of the discharge.
IV. Hidden Factors of the External Environment
Vibration and foundation settlement
The resonance generated by heavy equipment (such as crushers and large fans) near the packaging scale during its start-up, shutdown or operation will be transmitted to the scale's support through the factory's foundation. This slight vibration will cause the sensor to produce false signals, affecting the stability of the reading.
2. Fluctuations in climatic conditions
The thermal expansion and contraction of equipment caused by the temperature difference between day and night, as well as the pressure changes brought about by the monsoon, although not easily noticeable, will gradually have a minor impact on high-precision measuring equipment over time.
V. Systematic Solution Suggestions
When encountering the problem of inaccurate material cutting (either too heavy or too light), the following comprehensive measures are recommended:
• Regular cleaning and maintenance: Establish strict schedules to remove accumulated dust from the inner walls of the silo, the discharge ports, and the flexible connections, ensuring the flexibility of the mechanical moving parts.
• Conduct physical calibration: Do not rely solely on theoretical calculations. Instead, use standard weights or objects with known weights for multiple-point calibration, allowing the system to relearn the current physical state.
• Fine-tuning dynamic parameters: While the equipment is operating stably, attempt to slightly adjust the "pre-stop quantity before target value" or the "compensation coefficient", observe the trend and record the parameter combination with the smaller deviation.
• Isolate the vibration source: Check whether the anchor bolts of the packaging scale are securely fastened. If necessary, add shock-absorbing pads or vibration trenches at critical locations.
Through the above multi-dimensional investigation and adjustment, it is usually possible to effectively solve the weight deviation problem of the material feeding of the bag packaging scale, and improve the stability and qualification rate of the entire packaging line.
