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How to troubleshoot common problems in a manual piston paste filling machine?

2025-06-10

Hey there! As a supplier of manual piston paste filling machines, I've seen my fair share of common problems that users run into. In this blog, I'm gonna walk you through how to troubleshoot these issues so you can keep your filling machine running smoothly.

Problem 1: Inconsistent Filling Volumes

One of the most common problems with manual piston paste filling machines is inconsistent filling volumes. You might notice that some containers are overfilled while others are underfilled. This can be a real headache, especially if you're trying to maintain quality control.

Possible Causes

Worn Piston Seals: Over time, the piston seals can wear out, causing leaks and inconsistent filling. If you notice that the filling volumes are getting more and more inconsistent, it's a good idea to check the piston seals.
Incorrect Piston Stroke Adjustment: The piston stroke determines how much paste is drawn into the piston and then dispensed into the container. If the stroke is not adjusted correctly, you'll get inconsistent filling volumes.
Clogged Nozzles: A clogged nozzle can restrict the flow of paste, leading to underfilled containers. This can happen if the paste has a high viscosity or if there are solid particles in the paste.

Solutions

Replace the Piston Seals: If the piston seals are worn out, simply replace them with new ones. Make sure to choose seals that are compatible with your filling machine and the type of paste you're filling.
Adjust the Piston Stroke: Refer to your machine's manual to find out how to adjust the piston stroke. You may need to use a wrench or other tools to make the adjustment. Once you've made the adjustment, test the machine to see if the filling volumes are more consistent.
Clean the Nozzles: To clean the nozzles, remove them from the machine and soak them in a cleaning solution. Use a brush to gently scrub away any debris or clogs. Rinse the nozzles thoroughly and reinstall them on the machine.

Problem 2: Leaking Paste

Leaking paste can be a messy and wasteful problem. It can also make a mess of your work area and contaminate other products.

Possible Causes

Loose Fittings: If the fittings on the filling machine are not tightened properly, paste can leak out. This can happen at the connections between the piston, the cylinder, the nozzles, and the hoses.
Damaged Hoses: Over time, the hoses can become damaged or cracked, causing leaks. This can happen if the hoses are exposed to high temperatures, chemicals, or sharp objects.
Worn Seals in the Cylinder: Similar to the piston seals, the seals in the cylinder can also wear out over time, leading to leaks.

Solutions

Tighten the Fittings: Use a wrench or other tools to tighten the fittings on the filling machine. Make sure not to over-tighten them, as this can damage the fittings or the machine.
Replace the Hoses: If the hoses are damaged, replace them with new ones. Make sure to choose hoses that are compatible with your filling machine and the type of paste you're filling.
Replace the Cylinder Seals: If the seals in the cylinder are worn out, replace them with new ones. This may require some disassembly of the machine, so make sure to follow the instructions in your machine's manual.

Problem 3: Difficulty in Piston Movement

If you're having trouble moving the piston up and down, it can be difficult to operate the filling machine.

Possible Causes

Lack of Lubrication: The piston and cylinder need to be lubricated to ensure smooth movement. If there is not enough lubrication, the piston may stick or move slowly.
Debris in the Cylinder: Debris or paste residue in the cylinder can also cause the piston to stick or move slowly. This can happen if the machine is not cleaned regularly.
Misaligned Piston: If the piston is not aligned correctly in the cylinder, it can cause resistance and make it difficult to move.

Solutions

Lubricate the Piston and Cylinder: Apply a small amount of lubricant to the piston and cylinder. Make sure to use a lubricant that is compatible with your filling machine and the type of paste you're filling.
Clean the Cylinder: Remove the piston from the cylinder and clean the inside of the cylinder with a cleaning solution. Use a brush to gently scrub away any debris or paste residue. Rinse the cylinder thoroughly and reinstall the piston.
Align the Piston: If the piston is misaligned, you may need to adjust it. Refer to your machine's manual for instructions on how to align the piston.

Problem 4: Air Bubbles in the Filled Containers

Air bubbles in the filled containers can be a cosmetic issue, but they can also affect the quality and shelf life of the product.

Possible Causes

Inadequate Degassing: If the paste is not properly degassed before filling, air bubbles can get trapped in the paste and end up in the filled containers.
Fast Filling Speed: Filling the containers too quickly can cause air to be trapped in the paste.
Incorrect Nozzle Design: The design of the nozzle can also affect the formation of air bubbles. If the nozzle is not designed to minimize air entrainment, you'll get more air bubbles in the filled containers.

Solutions

Degas the Paste: Use a degassing machine or other degassing method to remove air bubbles from the paste before filling. This can help reduce the number of air bubbles in the filled containers.
Reduce the Filling Speed: Slow down the filling speed to allow the air to escape from the paste as it is being filled into the containers.
Choose the Right Nozzle: Consider using a nozzle that is designed to minimize air entrainment. There are different types of nozzles available, such as anti-drip nozzles and bottom-up filling nozzles, that can help reduce air bubbles.

Other Tips for Troubleshooting

Keep a Maintenance Log: Keeping a maintenance log can help you track when you last performed maintenance tasks, such as replacing seals or cleaning the machine. This can help you identify patterns and prevent problems from occurring.
Follow the Manufacturer's Instructions: Always follow the manufacturer's instructions for operating and maintaining your filling machine. This can help ensure that the machine operates correctly and reduces the risk of problems.
Train Your Operators: Make sure your operators are properly trained on how to use and troubleshoot the filling machine. This can help prevent operator error and ensure that the machine is used correctly.

If you're still having trouble troubleshooting the problems with your manual piston paste filling machine, don't hesitate to reach out to us. We're here to help you keep your machine running smoothly. And if you're in the market for a new filling machine, we also offer a range of other filling machines, such as the Automatic Rotor Pump Paste Filling Machine, Semi-automatic Spout Bag Filling Machine, and Full Automatic Rotor Pump Filling Machine.

If you're interested in learning more about our products or have any questions about troubleshooting your filling machine, feel free to contact us for a procurement discussion. We look forward to working with you!