Overview
Grade changes involve transitioning from one paper grade to another, typically requiring different target basis weights, control parameters, and valve positions. The system supports saving and recalling grade-specific settings.
Grade Management
Grade Database
Grades store all settings required for a specific product:
| Setting Category | Parameters Saved |
|---|---|
| Target Profile | Target basis weight, target profile shape |
| Control Parameters | Control gain, interval, filter depth, deadband |
| Valve Positions | Default valve positions, position limits |
| Zone Settings | Zone modes, enabled/disabled zones |
Creating a New Grade
-
Open Grade Manager
Navigate to Operations > Grade Manager
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Click New Grade
Enter a unique grade name (e.g., "Kraft 80gsm")
-
Configure Parameters
- Set target basis weight
- Adjust control parameters for this grade
- Configure default valve positions
-
Save Grade
Click Save to store the grade configuration
Editing Existing Grades
To modify a saved grade:
- Select grade from the dropdown list
- Click Edit
- Modify parameters as needed
- Click Save to update
After running a grade and achieving good control, save the current settings back to the grade. This captures optimized parameters for future use.
Grade Change Procedure
-
Prepare for Change
Before initiating grade change:
- Notify operators of upcoming change
- Verify new grade exists in database
- Review new grade parameters
-
Disable Auto Control (Optional)
For major grade changes, consider temporarily switching to Manual mode to prevent aggressive control actions during transition.
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Select New Grade
From the Grade selector dropdown, choose the target grade
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Apply Grade
Click Apply Grade to load settings:
- Target profile updates to new basis weight
- Control parameters change to grade settings
- Valve positions move to saved defaults (if enabled)
-
Re-enable Auto Control
Once basis weight stabilizes near target, enable Auto control mode
-
Monitor and Adjust
Watch profile 2-sigma as control engages:
- Profile should converge toward target
- Fine-tune control gain if response is too slow or oscillating
If the "Apply Default Positions" option is enabled, valve positions will move to saved defaults. Ensure this is appropriate before applying the grade.
Best Practices
Grade Naming Conventions
Use consistent naming for easy identification:
ProductType_Weight_Variant- e.g., "Kraft_80gsm_Standard"- Include basis weight in name
- Add variant suffix for different machines or conditions
Parameter Guidelines by Grade Type
| Grade Type | Basis Weight | Typical Gain | Notes |
|---|---|---|---|
| Light grades | < 60 g/m² | 0.3 - 0.4 | Lower gain, more sensitive |
| Medium grades | 60 - 120 g/m² | 0.4 - 0.5 | Standard settings |
| Heavy grades | > 120 g/m² | 0.5 - 0.6 | Higher gain acceptable |