Every time a Konica Minolta bizhub photocopier prints a page, not all toner is transferred to the paper. A small amount of toner remains on the drum, the Intermediate Transfer Belt (ITB), and other image-forming components. If this residual toner is not removed before the next print cycle, it can contaminate the next image and cause print defects.
The Cleaning System is responsible for removing this unused toner, collecting it, and transporting it to the waste toner container. Although it operates quietly in the background, it is one of the most important systems for maintaining consistent print quality and preventing internal contamination.
For field technicians, understanding the cleaning system is essential because failures in this system can produce symptoms such as ghost images, vertical streaks, repeating marks, toner scatter, and waste toner errors.
What Is Waste Toner?
Waste toner is toner that is not permanently fused onto the paper.
Residual toner remains after several stages of the printing process:
- After toner transfers from the drum to the Intermediate Transfer Belt.
- After toner transfers from the Intermediate Transfer Belt to the paper.
- During calibration and image stabilization routines.
- During automatic cleaning cycles.
- During service mode test prints.
This toner cannot be reused because it may contain paper dust, developer particles, and other contaminants.
Why the Cleaning System Is Necessary
The electrophotographic process is based on precision. If residual toner remains on the drum or transfer belt, it will be carried into the next print cycle.
Without proper cleaning, the machine may produce:
- Ghost images
- Repeating marks
- Background toner
- Color contamination
- Toner buildup inside the machine
- Premature wear of image-forming components
The cleaning system ensures that every print cycle begins with clean imaging surfaces.
Components of the Cleaning System
A typical Konica Minolta bizhub color machine includes several cleaning mechanisms.
Drum Cleaning Unit
Each drum has its own cleaning assembly consisting of:
- Cleaning Blade
- Recovery Roller (model dependent)
- Waste Toner Channel
Intermediate Transfer Belt Cleaning Unit
The ITB cleaning assembly includes:
- ITB Cleaning Blade
- Cleaning Roller (model dependent)
- Waste Toner Collection Channel
Waste Toner Transport System
Collected toner is transported by:
- Waste Toner Augers
- Transport Screws
- Toner Conveyance Tubes
These components move waste toner toward the waste toner bottle.
Waste Toner Bottle
The waste toner bottle stores collected toner until it reaches capacity.
Sensors monitor the bottle to prevent overflow.
Step 1: Cleaning the Drum
After the toner image transfers from the drum to the Intermediate Transfer Belt, a small amount of toner remains on the drum surface.
As the drum rotates:
- The cleaning blade contacts the drum.
- Residual toner is scraped from the drum.
- The toner falls into the waste toner channel.
The drum surface is now clean and ready for electrical discharge before the next print cycle.
The Drum Cleaning Blade
The cleaning blade is made from flexible polyurethane or a similar wear-resistant material.
Its functions include:
- Removing residual toner
- Preventing image carryover
- Maintaining a clean drum surface
- Protecting image quality
The blade must maintain consistent pressure against the rotating drum.
Too much pressure accelerates drum wear.
Too little pressure allows toner to remain on the drum.
Step 2: Cleaning the Intermediate Transfer Belt
After the complete CMYK image transfers from the Intermediate Transfer Belt to the paper, a small amount of toner remains on the belt.
The ITB Cleaning Blade removes this toner.
Residual toner enters the waste toner transport system.
If the belt is not cleaned properly, leftover toner may contaminate future prints.
Step 3: Transporting Waste Toner
Waste toner cannot remain inside the cleaning unit.
Several augers continuously transport the collected toner through enclosed channels.
The transport system moves toner:
Cleaning Blade → Waste Channel → Auger → Transport Tube → Waste Toner Bottle
This transport process occurs automatically while printing.
Step 4: Waste Toner Collection
The waste toner bottle collects toner from:
- Drum cleaning units
- Intermediate Transfer Belt cleaning unit
- Calibration routines
- Internal cleaning operations
The bottle is removable for replacement or emptying, depending on the machine model.
Waste Toner Detection
Most Konica Minolta bizhub machines monitor the waste toner bottle using sensors.
Depending on the model, detection may involve:
- Optical sensors
- Mechanical actuators
- Toner level monitoring
When the bottle becomes full, the machine displays a message instructing the user to replace or empty the waste toner container.
Ignoring this warning can lead to toner overflow and contamination inside the machine.
Automatic Cleaning During Calibration
The cleaning system also operates during several maintenance routines.
Examples include:
Image Stabilization
Test patterns are printed and measured.
Unused toner is removed afterward.
Gradation Adjustment
Calibration charts generate additional waste toner that must be collected.
Color Registration
Registration marks are cleaned from the Intermediate Transfer Belt after measurement.
Relationship to the Electrophotographic Process
The cleaning system operates after image transfer and before the next print cycle.
The complete sequence is:
- Charging
- Laser Exposure
- Development
- Primary Transfer
- Secondary Transfer
- Fusing
- Cleaning
- Drum Erasing
- Next Print Cycle
Cleaning restores the imaging components to their original condition.
Common Cleaning System Problems
| Symptom | Possible Cause |
|---|---|
| Ghost images | Worn drum cleaning blade or toner remaining on the drum |
| Repeating marks | Damaged cleaning blade, contaminated drum, or cleaning failure |
| Toner scatter inside machine | Waste toner transport blockage or overflowing waste toner bottle |
| Background toner | Cleaning blade not removing residual toner effectively |
| Vertical streaks | Toner buildup on the drum or damaged cleaning blade edge |
| Color contamination | ITB cleaning failure allowing toner to remain on the belt |
| Waste toner full message | Full waste toner bottle or faulty waste toner sensor |
| Toner leaking inside machine | Cracked waste toner bottle, disconnected transport tube, or clogged auger |
Preventive Maintenance
The cleaning system should be inspected during scheduled maintenance.
Recommended procedures include:
- Inspect drum cleaning blades for wear or hardening.
- Check the ITB cleaning blade for damage or contamination.
- Empty or replace the waste toner bottle as specified by the service manual.
- Inspect augers for toner buildup or blockages.
- Clean waste toner sensors if contamination is present.
- Ensure all transport tubes are securely connected.
- Remove excess toner from the machine interior using an approved toner vacuum.
- Never use compressed air to remove toner, as it can disperse fine particles throughout the machine and damage sensitive components.
Diagnostic Tips for Technicians
When cleaning-related print defects occur:
- Print several solid-color test pages and inspect for repeating defects.
- Check whether defects repeat at intervals corresponding to the drum or ITB circumference.
- Inspect drum cleaning blades for wear, curling, or toner buildup.
- Examine the Intermediate Transfer Belt for residual toner after printing.
- Verify that waste toner augers rotate freely.
- Inspect the waste toner bottle and sensors for overflow or blockage.
- Confirm that toner is reaching the waste toner bottle instead of accumulating inside the machine.
A systematic inspection helps identify the actual source of contamination before replacing major components.
Why Understanding the Cleaning System Matters
Many print-quality defects originate after the image has been formed correctly. A perfectly functioning drum, developer unit, and laser system cannot produce clean prints if residual toner is left on the drum or Intermediate Transfer Belt.
Understanding the cleaning system allows technicians to distinguish image formation problems from image contamination problems, improving troubleshooting accuracy and reducing unnecessary replacement of expensive imaging components.
Conclusion
The cleaning system in a Konica Minolta bizhub photocopier removes residual toner from the drum units and Intermediate Transfer Belt after every print cycle, transports it through an enclosed waste toner system, and stores it safely in the waste toner bottle. By ensuring that all imaging surfaces are clean before the next page is printed, the system prevents ghost images, repeating marks, background toner, and internal contamination. A thorough understanding of the cleaning process enables technicians to diagnose print-quality issues more efficiently, maintain reliable machine performance, and extend the service life of critical imaging components.