1. Liquid overflow: During the liquid filling process, overflow may occur, which may be caused by too fast filling speed or too high liquid viscosity. The solution is to reduce the filling speed or dilute the liquid appropriately.

2. Mixed colors: Sometimes the filled liquid appears mixed in color. This may be caused by the equipment not being thoroughly cleaned or the liquid from the previous filling not being completely removed. The solution is to thoroughly clean the equipment and ensure that the previous filling is completely emptied.

3. Inaccurate filling: Sometimes the amount of liquid filled is not accurate enough, which may lead to unstable product quality or waste. The solution is to ensure the accuracy and stability of the filling equipment and check and calibrate it regularly.

4. Bottle caps are not tight: After filling, sometimes the bottle caps are not tightened properly, causing liquid leakage or contamination. The solution is to check the quality and tightness of the bottle caps and ensure that the equipment is adjusted correctly.

5. Foam generation: Sometimes a lot of foam will be generated during the liquid filling process. This may be caused by too fast filling speed or the presence of air or impurities in the liquid. The solution is to reduce the filling speed, regularly check the equipment cleanliness, and ensure that the liquid quality meets the requirements.

6. Valve blockage: The valve of the liquid filling line may be blocked, causing the liquid to not flow normally. The solution is to clean the valve regularly and ensure that the liquid used in the equipment meets the requirements.

7. Inaccurate liquid temperature control: When filling liquids, temperature control may be required for certain products. If the temperature control is inaccurate, it may affect the product quality. The solution is to ensure that the equipment temperature control is accurate and regularly check and calibrate the temperature sensor.

8. Waste of consumables: During the liquid filling process, there may sometimes be waste of consumables, such as overflow, liquid reflux, etc. The solution is to optimize the filling speed and volume, and ensure the adaptability of the equipment and container to reduce waste.

9. Equipment failure: Liquid filling line equipment may have various failures, such as electrical failure, mechanical failure, etc. The solution is to regularly check the equipment operation status, maintain and repair it in time, and keep the equipment clean and tidy.

10. Human operational errors: On the liquid filling line, improper operation by the operator may lead to problems, such as improper settings, operating errors, etc. The solution is to train and guide the operators to ensure the operation is standardized and accurate.

The above are some examples of common problems and solutions for liquid filling lines. Other problems may arise in actual production. For each problem, the solution may vary depending on the specific situation and needs to be analyzed and handled according to the actual situation. The key is to maintain the normal operation of the equipment and the stability of production, to ensure the improvement of product quality and production efficiency.