Introduction
Even with regular maintenance, flow wrapper problems will occur. The key is knowing how to quickly diagnose and resolve these issues to minimize downtime.
Prevention is always better than repair — follow our daily maintenance checklist to minimize downtime.
This troubleshooting guide organizes the most common problems by category, with clear symptoms, causes, and solutions. We’ve organized the most common problems by category, with clear symptoms, causes, and solutions.
Key Takeaway: Most flow wrapper problems can be solved by checking seal temperature, film tracking, and component wear. Learn these basics and save hours of downtime.
How to Use This Guide
For each problem, you’ll find:
1. Symptoms – What you’ll observe
2. Likely Causes – Most common reasons
3. Quick Solutions – Step-by-step fixes
4. Prevention Tips – How to avoid recurrence
Part 1: Seal Quality Problems
Problem 1: Weak or Failed Seals
Symptoms:
– Seals separate easily when pulled
– Packages open during handling
– Product visible through seal area
– Inconsistent seal strength
Diagnostic Checklist:
| Check | Normal | Problem Indicator |
|---|---|---|
| Seal temperature | ±5°C of setting | Large variation |
| Seal tape thickness | >0.5mm | Worn <0.3mm |
| Seal pressure | Consistent | Fluctuating |
| Film type | Matched to temp | Wrong film |
Solutions:
- Check and adjust seal temperature
- Use calibrated thermometer to verify
- Increase by 5°C increments
-
Re-test seal strength
-
Replace seal tape
- Remove old tape with sealant remover
- Clean surface completely
- Apply new tape evenly
-
Press firmly
-
Check seal pressure
- Inspect springs for fatigue
- Replace if compressed
-
Adjust pressure settings
-
Verify film compatibility
- Check film specifications
- Confirm seal temperature range
- Try known-good film sample
Problem 2: Seal Sticking or Burn Marks
Symptoms:
– Film sticks to seal bar
– Burn marks on film
– Film tears at seal
– Product damage from heat
Solutions:
- Reduce seal temperature
- Decrease by 5-10°C
- Test with sample packages
-
Find minimum effective temperature
-
Clean seal bar
- Use non-abrasive cleaner
- Remove all residue
- Apply anti-stick coating
-
Never use metal tools
-
Check seal timing
- Verify dwell time is correct
- Inspect cam wear if applicable
- Check for timing drift
Problem 3: Uneven or Crooked Seals
Symptoms:
– Seal not centered on package
– One side stronger than other
– Wrinkled seal edges
– Asymmetric appearance
Solutions:
- Realign seal bar
- Check bar is parallel to anvil
- Adjust using alignment tools
-
Verify with test packages
-
Replace worn anvil
- Inspect wear pattern
- Rotate or replace anvil
-
Ensure proper seating
-
Check film tracking
- Film must be centered
- Adjust tracking guides
- Verify dancer tension
Part 2: Film Handling Problems
Problem 4: Film Wrinkling
Symptoms:
– Wrinkled film on finished package
– Wrinkles near seal areas
– Visual quality issues
– Product damage from wrinkles
Diagnostic Flowchart:
Film Wrinkling
↓
Is wrinkle in seal area?
↓ YES ↓ NO
Check seal timing Check film path
↓ ↓
Check anvil condition Check tension
↓ ↓
Verify pressure Verify forming collar
Solutions:
- Adjust film tracking
- Loosen film path
- Manually center film
- Retighten gradually
-
Run and observe
-
Check forming collar
- Verify size matches product
- Check for wear or damage
-
Adjust collar position
-
Reduce film tension
- Check dancer operation
- Adjust brake tension
- Verify film properties
Problem 5: Film Tears or Breaks
Symptoms:
– Film breaks during operation
– Torn edges on package
– Frequent line stops
– Product exposed
Solutions:
- Identify tear location
- Near unwind: check edge quality
- Near former: check collar
-
Near seal: check seal timing
-
Check for sharp edges
- Inspect all rollers
- Check forming collar edges
-
Look for nicks or burrs
-
Adjust film tension
- Reduce brake tension
- Check dancer operation
-
Verify film properties
-
Use edge guide
- Install edge sensor
- Enable auto-tracking
- Check guide rollers
Problem 6: Film Tracking Problems
Symptoms:
– Film drifts to one side
– Film overlaps incorrectly
– Seal position varies
– Edge variations
Solutions:
- Manual tracking adjustment
- Loosen tracking roller
- Move roller in small increments
- Observe film behavior
-
Repeat until centered
-
Install edge guide
- Add edge sensor
- Connect to tracking adjustment
-
Enable auto-correction
-
Check dancer/square system
- Verify smooth movement
- Lubricate if needed
- Replace worn components
Part 3: Package Quality Problems
Problem 7: Incorrect Package Length
Symptoms:
– Packages too long or short
– Variable package lengths
– Seal positions inconsistent
– Product count per box varies
Solutions:
- Check encoder function
- Verify encoder clean
- Check mounting security
-
Test encoder output
-
Calibrate length setting
- Measure actual package
- Compare to HMI setting
- Adjust if needed
-
Retest
-
Check product spacing
- Verify timing screw adjustment
- Check product sensors
- Ensure consistent infeed
Problem 8: Product Misalignment
Symptoms:
– Product not centered in film
– Product contacts seal area
– Crooked packages
– Product damage
Solutions:
- Adjust infeed guides
- Center product on belt
- Align with forming area
-
Check for wear
-
Verify timing
- Check sensor position
- Verify timing screw setting
-
Adjust product spacing
-
Inspect conveyor belt
- Check belt condition
- Verify tracking
- Ensure proper tension
Problem 9: Wrapped Product Damage
Symptoms:
– Product crushed or deformed
– Product marks on film
– Leaking packages
– Customer complaints
Solutions:
- Reduce film tension
- Loosen gathering tension
- Adjust roller pressure
-
Test with product samples
-
Adjust folding plates
- Reduce pressure on product
- Verify plate positioning
-
Check for wear
-
Modify speed settings
- Reduce line speed
- Check acceleration
- Verify product handling
Part 4: Electrical and Control Problems
Problem 10: Machine Won’t Start
Safety First: Always check electrical issues with power OFF.
Diagnostic Sequence:
- Check emergency stop
- Verify E-stop not engaged
- Reset if needed
-
Test restart
-
Check guards
- All guards closed
- Interlock switches functioning
-
Reset if needed
-
Check power supply
- Main breaker on
- Voltage correct
-
Phase sequence correct
-
Check PLC status
- Power indicator lit
- No fault codes
- Restart controller if needed
Problem 11: HMI Touch Screen Unresponsive
Symptoms:
– Screen doesn’t respond to touch
– Commands not executing
– Frozen display
– Error messages
Solutions:
- Restart HMI
- Power cycle HMI
- Wait 30 seconds
-
Restart machine
-
Clean screen
- Use soft, damp cloth
- Avoid harsh cleaners
-
Never use solvents
-
Check connections
- Verify Ethernet cable
- Check connector security
-
Replace cable if damaged
-
Update firmware
- Download latest version
- Follow update procedure
- Back up current settings
Problem 12: Temperature Reading Errors
Symptoms:
– Temperature display shows “–”
– Wildly fluctuating temps
– Temperature won’t reach setpoint
– Over-temperature alarms
Solutions:
- Check thermocouple
- Verify connection
- Clean contacts
-
Replace if damaged
-
Check heater element
- Measure resistance
- Verify continuity
-
Replace if open
-
Check SSR (Solid State Relay)
- Check for output voltage
- Replace if failed
- Verify heat sink
Part 5: Mechanical Problems
Problem 13: Unusual Noise or Vibration
Symptoms:
– Grinding or squealing sounds
– Excessive vibration
– Rattling noises
– Impact sounds
Diagnostic Approach:
| Sound Type | Likely Source | Action |
|---|---|---|
| Grinding | Bearings | Replace |
| Squealing | Belt slip | Tension or replace |
| Rattling | Loose parts | Tighten |
| Impact | Misalignment | Realign |
Solutions:
- Identify noise source
- Run without film
- Run without product
-
Isolate which section
-
Check bearings
- Listen for roughness
- Check for play
-
Replace if needed
-
Check belts
- Inspect for wear
- Check tension
- Replace if cracked
Problem 14: Speed Variation or Instability
Symptoms:
– Speed fluctuates
– Can’t reach target speed
– Stops at high speed only
– Speed different than display
Solutions:
- Check drive system
- Motor condition
- Belt condition
-
Encoder feedback
-
Check PLC configuration
- Verify speed settings
- Check acceleration/deceleration
-
Reset to defaults if needed
-
Verify power supply
- Check voltage stability
- Measure current draw
- Check for interference
Quick Reference Troubleshooting Matrix
| Problem | First Check | Second Check | Third Check |
|---|---|---|---|
| Weak seal | Temperature | Seal tape | Pressure |
| Wrinkling | Film tracking | Forming collar | Dancer |
| Film tear | Sharp edges | Tension | Film quality |
| Length error | Encoder | Sensor | PLC settings |
| Won’t start | E-stop | Guards | Power |
| No heat | Thermocouple | Heater | SSR |
| Noise | Bearings | Belts | Alignment |
When to Call Technical Support
Call immediately if:
– Electrical damage or burning smell
– Pneumatic system issues
– PLC or HMI replacement
– Safety system malfunctions
– Major component replacement
Information to have ready:
– Machine model and serial number
– PLC and HMI firmware versions
– Error codes displayed
– Problem description and when it started
– Steps already tried
Conclusion
Most flow wrapper problems have straightforward causes and solutions. By understanding these common issues and their fixes, you can reduce downtime and maintain production efficiency.
Key Takeaways:
1. Start with the simplest causes first
2. Document problems and solutions
3. Check seal components first for seal issues
4. Verify film handling for film problems
5. Contact support for complex issues
Need technical support?
Path Pack builds horizontal packaging machines in Hangzhou, China. Every machine is tested with the customer’s product and film before it ships. If you are evaluating a flow wrapper or troubleshooting a line already in production, contact our engineering team — we reply within one working day.
About Path Pack
For seal-related issues, refer to our cut-off knife adjustment guide.
🛠️ Hands-on guide: For step-by-step instructions on your machine, see the Troubleshooting Center in the Path Pack Support Center.
