Common bag making machine problems and solutions: practical guide and solutions

As core equipment in the packaging industry, bag-making machines' stable operation is directly related to production efficiency and product quality. Operators will inevitably encounter various problems during actual operation. This article will detail common bag-making machine issues and their solutions, providing a reference for routine maintenance and troubleshooting.

1. Overview of the basic principle and structure of bag making machine

Before delving into specific issues, it's important to first understand the basic working principles of a bag-making machine. A bag-making machine primarily produces plastic bags through processes such as unwinding, forming, heat-sealing, cooling, and bag cutting. The heat-sealing and cutting systems are the most prone to problems. The machine consists of three major components: the electrical control system, the mechanical transmission system, and the actuator. Any malfunction in any of these components can affect the entire machine.

2. Common mechanical problems and solutions

1. The cutter does not cut continuously or the bags are not cut neatly

This is one of the most common production issues. First, check if the cutter is worn or blunt. If so, replace the blade. Next, adjust the cutter position to ensure the upper and lower blades are fully aligned. If using a heated cutter, also check that the heating temperature has reached the set value. Finally, check if the blade holder screws are loose and tighten if necessary.

2. The seal is not firm or leaks

Sealing quality directly impacts the performance of packaging bags. Poor seals are primarily caused by insufficient heat sealing temperature, insufficient pressure, or too short a sealing time. Check the heat sealer's heating element for proper operation and pressure regulation. Also, check the material's suitability for the current temperature setting; different plastic thicknesses require different heat sealing parameters.

3. Film deviation (film material deviation)

Film deviation can lead to problems such as asymmetrical bag shapes and misaligned printed patterns. First, adjust the unwinding and rewinding tension to maintain balanced film tension. Next, check that the guide rollers are parallel and that the surfaces of the rollers are clean and free of contaminants. Installing a photoelectric web-correction system can effectively resolve persistent web deviation issues.

4. Abnormal noise in the transmission system

Abnormal noise often comes from worn gears, damaged bearings, or insufficient lubrication. Lubricate transmission components regularly and check gear clearances for proper function. Worn parts should be replaced promptly to prevent further damage.

3. Troubleshooting of electrical control systems

1. The motor cannot start

First, check that the power is on and then check if the fuse is blown. For inverter-controlled motors, verify that the parameters are set correctly and reset the inverter if necessary. A fault in the motor itself is also a possible cause; use specialized equipment to test the motor windings.

2. Temperature control system malfunction

Inaccurate temperature control can directly affect sealing quality. Check for damaged thermocouples or poor contact, proper operation of solid-state relays, and burnout of heaters. Regularly calibrating temperature control instruments can reduce these issues.

3. PLC program error

Modern bag-making machines often use PLC control systems. Program errors can cause the machine to malfunction. These errors can be corrected by re-entering the program or restarting the system. Always back up the original program to prevent accidental loss.

4. Material-related issues and solutions

1. Poor film adhesion

Film that is too sticky or too slippery can affect the bag-making process. Adjust the tension setting and guide roller angle based on the material's characteristics. Properly adjusting the workshop temperature and humidity within acceptable limits can also improve film processing performance.

2. Printing pattern misalignment

This problem is often caused by insufficient sensitivity or contamination of the photoelectric eye. Clean the photoelectric eye surface and adjust the tracking sensitivity. Also, check the quality of the printing film itself. Excessive printing errors are difficult to fully correct through equipment adjustments.

5. Key points for process parameter setting

Correct process parameters are crucial for ensuring bag quality. Temperature, pressure, and speed all require coordinated adjustment. Generally speaking, thicker materials require higher temperatures and pressures, but production speeds should be reduced to ensure sufficient heat-sealing time. The optimal parameter combination should be re-adjusted each time material specifications change.

6. Daily maintenance and maintenance specifications

Prevention is better than cure, and regular maintenance can significantly reduce the likelihood of failures. Daily maintenance should include cleaning the machine's exterior and interior to remove accumulated dust, checking for loose fasteners, lubricating moving parts, and replacing wearing parts. It's recommended to develop a detailed maintenance schedule that includes daily, weekly, and monthly inspections.

It is particularly important to cut off the power supply before maintaining the equipment to ensure safe operation. Adjustments to precision parts should preferably be performed by professional technicians or under their guidance.

7. Precautions for safe operation

As a large piece of machinery, bag-making machines must comply with safety regulations during operation. Operators should receive professional training and be familiar with the location and use of emergency stop buttons. Hands should not be placed in hazardous areas while the machine is running. Cleaning or adjustments must be performed only when the machine is stopped. Hot parts should be clearly marked and isolated to prevent burns.

Troubleshooting bag-making machine problems requires systematic thinking and extensive experience. Operators should be familiar with the equipment manual and understand the basic principles of the machine to quickly and accurately identify the problem. The common problems and solutions listed in this article cover most practical situations, but each machine is unique and requires flexible application in actual operation. Maintaining a detailed equipment maintenance file, recording each malfunction, cause, and solution, will be an invaluable reference for future troubleshooting. Through scientific maintenance and standardized operation, your bag-making machine will remain in optimal working condition, providing a reliable guarantee for producing high-quality products.

Remember, when you encounter complex problems that cannot be solved, you should contact professional maintenance personnel in time to avoid greater losses due to improper maintenance.