Applicable Systems
Roland Offset Printing Machine
Symptoms
The printing blanket has a visible tear or lump. The printed image shows a repeating defect at the blanket cylinder circumference.
Possible Causes
- Blanket damaged by a paper web break or foreign object passing through the nip
- Blanket over-tightened during installation causing edge damage
- Blanket glue layer degraded from excessive solvent wash
- Blanket undercut too deep, causing paper embossing and early failure
Troubleshooting Steps
- Step 1: Remove the blanket and inspect the surface for tears, lumps, or chemical damage
Replace the blanket if any visible damage is found - Step 2: Clean the blanket cylinder surface and inspect for damage
Resurface the cylinder if it is scored or corroded - Step 3: Install the new blanket with the correct tension per the manual specification
Use a torque wrench on the blanket tensioning mechanism - Step 4: Verify the blanket undercut is correct using a depth gauge
Adjust the packing to achieve the correct impression pressure
How to Reset
Reset: After blanket replacement, run test prints and verify the defect is eliminated.
Common Replacement Parts
- Printing blanket: Compressible type, 1.95mm thick (Match to press model and application)
- Blanket packing: Calibrated paper, 0.05-0.10mm (For impression adjustment)
- Torque wrench: 0-50 Nm, calibrated (For blanket tensioning)
Frequently Asked Questions
- Q: How often should blankets be replaced?
After 10-30 million impressions, depending on paper quality and washing frequency. Inspect daily for damage.
- Q: How do I wash a blanket?
Use OEM-approved wash and a clean cloth. Wash in the direction of cylinder rotation. Avoid excessive solvent that degrades the blanket glue layer.
- Q: What is blanket undercut?
The depth that the blanket surface sits below the cylinder bearers. Correct undercut ensures proper impression pressure without embossing the paper.
Source: OEM Operation Manual
Category: Printing