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With the rapid growth of the global packaging industry, more manufacturers are choosing high-speed China bag making machines to improve production efficiency and reduce manufacturing costs. These machines are widely used for producing shopping bags, courier bags, garbage bags, zipper pouches, food packaging bags, and industrial heavy-duty packaging bags.
However, during long-term high-speed production, factories often encounter problems such as poor sealing, inaccurate bag length, film deviation, servo motor alarms, unstable cutting, and excessive material waste. If these issues are not solved quickly, they can lead to production downtime, increased operating costs, and customer complaints.
In this article, we will discuss the most common China bag making machine issues, their causes, troubleshooting methods, and preventive maintenance solutions. Whether you operate a side sealing bag making machine, bottom sealing bag making machine, wicket bag machine, pouch making machine, or FFS heavy-duty bag making machine, this guide can help improve production stability and machine lifespan.
Modern plastic bag production lines operate at extremely high speeds. Some advanced high speed bag making machines can now reach over 500 pcs/min, while multi-line systems can exceed 2000 pcs/min output capacity. Under these conditions, even a small machine problem may lead to serious production losses.
● Bag sealing defects
● Printing position errors
● Film feeding instability
● Bag length inconsistency
● Servo synchronization failures
● Material waste increase
● Production downtime
Factories that perform effective troubleshooting and preventive maintenance can significantly improve machine stability, product quality, and operational efficiency.
Bag sealing quality directly affects the strength, appearance, and usability of plastic packaging bags. Poor sealing is one of the most common issues in plastic bag production.
Several factors can cause weak or incomplete sealing:
● Incorrect sealing temperature
● Uneven sealing pressure
● Damaged heating elements
● Low-quality plastic film
● Excessive production speed
● Worn sealing knife
When sealing temperature is too low, the film layers cannot fully bond together. On the other hand, excessive temperature may burn the film and cause wrinkles or deformation.
Verify whether the sealing temperature matches the film material.
| Film Material | Recommended Temperature |
|---|---|
| HDPE | 140–180°C |
| LDPE | 120–160°C |
| PP Film | 160–220°C |
| Laminated Film | Depends on layer structure |
A worn or contaminated sealing knife often causes poor sealing consistency.
Check for:
● Carbon buildup
● Knife surface damage
● Uneven pressure
● Incorrect knife alignment
High-speed production may reduce sealing time. Lowering machine speed slightly can improve sealing quality.
Bag length inconsistency is especially common in high-speed side sealing bag making machines and bottom sealing machines.
● Different bag lengths
● Misaligned printing
● Incorrect cutting positions
● Unstable bag registration
The EPC (Edge Position Control) system maintains film alignment during production. If the EPC sensor is dirty or improperly calibrated, film deviation may occur.
Servo motors control film feeding and cutting accuracy. Incorrect servo parameters may result in unstable bag length.
Uneven tension stretches the plastic film, changing actual bag dimensions.
● Clean EPC sensors daily
● Recalibrate photoelectric tracking
● Check servo motor settings
● Maintain constant film tension
● Inspect encoder feedback signals
Advanced China bag making machines now use intelligent servo algorithms to improve bag length precision during ultra-high-speed production.
Film tracking problems can seriously affect bag appearance and production stability.
● Film drifting left or right
● Wrinkled feeding
● Printing offset
● Feeding vibration
● Unstable rewinding
| Cause | Impact |
|---|---|
| Dirty EPC sensor | Inaccurate correction |
| Loose rollers | Feeding instability |
| Uneven tension | Film wrinkles |
| Poor servo response | Printing misalignment |
Dust or film debris may interfere with sensor detection.
Misaligned rollers can cause continuous film drifting.
Modern automatic bag making machines use servo tension systems to maintain stable film feeding.
Servo systems are critical components in fully automatic bag making machines. When servo alarms occur, the entire production line may stop immediately.
● Overload operation
● Voltage fluctuation
● Encoder communication failure
● Incorrect PLC parameters
● Excessive acceleration settings
Loose cables or unstable connectors may interrupt communication signals.
Improper acceleration and deceleration settings can overload the servo system.
If machine speed exceeds the servo system capacity, overload alarms may occur.
Damaged encoders reduce positioning accuracy.
Cutting precision is extremely important for high-quality plastic bag production.
● Uneven cutting edges
● Incorrect cutting position
● Film tearing
● Excessive burrs
● Knife overheating
Flying knife systems experience wear during long-term high-speed operation.
Incorrect synchronization between feeding and cutting systems causes inaccurate cuts.
Weak machine structures may reduce cutting stability at high speeds.
Modern flying knife bottom sealing bag making machines provide:
● Higher cutting speed
● Better sealing appearance
● Reduced waste
● Improved production stability
● Better performance during continuous operation
Chovyting Machinery has continuously upgraded flying knife technology, achieving significant speed improvements in recent years.
Preventive maintenance helps reduce unexpected downtime and extend machine lifespan.
● Clean sealing bars
● Remove film dust
● Inspect sensors
● Lubricate moving parts
● Check air pressure
● Monitor heating temperature
| Maintenance Item | Purpose |
|---|---|
| Servo inspection | Prevent alarm failures |
| EPC calibration | Improve tracking accuracy |
| Roller cleaning | Stabilize film feeding |
| Knife inspection | Maintain cutting quality |
| Electrical cabinet cleaning | Prevent overheating |
● Check PLC parameters
● Inspect bearings
● Test cooling systems
● Tighten structural components
● Replace worn parts
Factories that follow regular maintenance schedules usually achieve much higher machine stability and lower maintenance costs.
China bag making machine manufacturers have significantly improved automation, speed, and stability over the past decade.
● Intelligent servo systems
● Automatic tension control
● Independent heating systems
● EPC automatic alignment
● Flying knife technology
● Heavy-duty steel machine structure
● Multi-line production systems
These technologies help factories:
● Improve productivity
● Reduce labor costs
● Lower material waste
● Increase sealing precision
● Maintain stable high-speed production
A professional bag making machine manufacturer should provide strong technical support and global service capabilities.
● 24-hour online support
● Overseas engineer service
● Spare parts inventory
● Installation and debugging
● Operator training
● Remote troubleshooting
Reliable after-sales service can significantly reduce production interruptions and improve machine efficiency.
China has become one of the world’s largest manufacturing centers for plastic bag making machinery.
Chinese manufacturers offer cost-effective machinery compared with European equipment.
Many Chinese manufacturers continuously improve machine speed and automation.
Modern manufacturers provide:
● Side sealing bag making machines
● Bottom sealing bag making machines
● Vest bag making machines
● Garbage bag making machines
● Zipper pouch making machines
● FFS heavy-duty bag making machines
Machines can be customized for:
● Shopping bags
● Courier bags
● Medical packaging
● Food packaging
● Industrial packaging
● Diaper packaging bags
As a professional China bag making machine manufacturer with over 25 years of industry experience, Chovyting Machinery focuses heavily on machine stability, precision, and automation.
● More than 100 patents
● 50+ invention patents
● 10,000㎡ production base
● 180+ employees
● Professional overseas technical team
● CE-certified equipment
● ISO quality management system
Chovyting’s machines feature:
● High-strength steel machine structures
● Intelligent servo control systems
● Advanced flying knife technology
● Stable EPC tracking systems
● High-speed production capability
● Comprehensive bag-making solutions
The company also provides global technical support and installation services in regions such as South America, the Middle East, Europe, Africa, and North America.
Troubleshooting common China bag making machine issues is essential for maintaining stable production, reducing waste, and improving factory profitability. Problems such as poor sealing, inaccurate bag length, film deviation, servo alarms, and cutting instability can often be solved through proper maintenance, parameter adjustment, and operator training.
Modern China bag making machine manufacturers are continuously improving automation, precision, and production speed to meet global packaging demands. Choosing a reliable manufacturer with strong R&D capability, advanced technology, and professional after-sales support can greatly improve long-term production performance and machine reliability.
For factories looking to increase efficiency and reduce downtime, investing in a high-quality automatic bag making machine is becoming increasingly important in the competitive global packaging industry.
Incorrect temperature settings, uneven pressure, worn sealing knives, or unstable film tension are common causes.
Bag length problems are usually caused by EPC tracking issues, unstable film feeding, or servo synchronization errors.
Daily cleaning and inspection are recommended, while deeper electrical and mechanical maintenance should be performed weekly and monthly.
EPC stands for Edge Position Control. It helps maintain accurate film alignment during production.
Servo alarms may occur because of overload operation, voltage fluctuation, encoder communication failure, or incorrect PLC parameters.
Flying knife systems improve cutting speed, sealing precision, and production efficiency while reducing waste.
Preventive maintenance, operator training, stable machine structures, and professional after-sales support all help reduce downtime.
Yes. Many China bag making machine manufacturers provide CE-certified equipment, overseas installation, and global technical support.
If you have any questions or need help,
feel free to contact with our team.
