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This
is the place where we address your questions as well
as problems related to printing. The section is designed
so that you can use it as a quick reference when you
encounter any issue with which you need advice.
Download "The
Advantages of Using Torque Wrenches" PDF
Download
"Technical Sales Sheet – Coating Blankets"
PDF
Download "Diagnosing
the Right Blanket" PDF
Download "Printing
Blanket Order Spec Sheet PDF
Download "Technical
Sales" PDF
Download
Troubleshooter Info PDF (Content below)
Ink Emulsification
Doubling in the Print (Circumferentially)
Doubling in the Print (Laterally)
Dot Gain too High
Ink Accumulation on Blanket in Non-Image Area
Linting
Piling
Blanket Delamination
Paper Edge Marking
Poor Solids
Gauge Loss
Poor Sheet Release
Excessive Plate Wear
Gapping of Blankets on Double Width
Presses
Paper Overfeed on Web Presses
Relief structure on blanket surface
Blanket surface glazing
If you have any questions, which aren’t answered
in this section or would prefer to talk to one of our
knowledgeable customer care consultants please don’t
hesitate to contact us anytime.
Ink emulsification
1. Fountain overfeed
Reduce water quantity
2. Extreme water pick-up of ink
Try ink with lower pick-up
3. Too “sharp” fountain solution
Adjust pH to 5 - 5.5
4. Too much alcohol in fountain
Adjust percentage to about 15%
5. Poor ink quality
Try higher quality ink
6. Too thin ink
Try thicker ink or add varnish
7. pH too high (over 6 pH)
Adjust pH to 5 - 5.5
8. Form roller setting to plate
Adjust proper pressure
9. Poor ink transfer to stock
Check nip pressure of plate/blanket/stock
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Doubling in the print
(circumferentially)
1. Blanket loose
Check blanket tension
2. Improper web tension (on webs)
Readjust tension
3. Untrue rolling conditions
Synchronize cylinder speeds
4. Mechanical defects
Inspect mechanical conditions
5. Different blanket types
Ensure that blankets in press are all of same type
6. Unsuitable subject lay down
Try to modify your ink tack accordingly
7. Different packing thickness
Ensure same packing height
8. Wet/damp packing
Change packing, reduce amount of solvent for blanket
cleaning
9. Improper packing height
Adjust packing to requirements
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Doubling in the print (laterally)
1. Incorrect paper quality
Ensure paper quality
2. Improper packing height
Adjust packing to requirements
3. Underpacking thickness variation
Ensure that packing is 100% equal on both sides
4. Mechanical settings
Ensure the cylinders are adjusted 100% spirit level
5. Incorrect blanket direction
Ensure correct blanket installation
6. Blanket uniformity
Check blanket for uniformity
7. Mechanical inconveniences
Check mechanical conditions of press
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Dot gain too high
1. Indentation value too high
Readjust to recommended value
2. Untrue rolling conditions
Synchronize rolling conditions
3. Too much water in ink
Adjust ink water balance to lower level or use different
ink
4. Form roller setting to plate
Adjust setting to recommendation
5. Unsuitable ink tack
Change ink to higher tack ink
6. Ink overload
Reduce ink value to optimum level for contrast/density
7. Unsuitable blanket surface
Change to blanket with very low dot gain value
8. Ink temperature too high
Keep ink level in fountain low for frequent refreshing
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Ink accumulation on blanket
in non-image area
1. Too low dampening level
Increase water supply to blanket surface
2. Too “fast” ink
Change color sequence or use “slower” inks
3. Ink tack too high
Reduce ink tack
4. Indentation in blanket/blanket nip too low
Check indentation value
5.
Blanket surface too smooth
Use rougher surface blanket
6. Blanket surface too tacky
Avoid the use of rejuvenators
7. Blanket exposed to heat
Keep heat of dryer away from blankets in last unit
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Linting
1. Loose fibers of paper
Change paper quality
2. Ink tack too high
Reduce tack
3. Dampening of previous cylinders too high
Reduce water to the paper
4. First impression
If possible, pre-squeeze the paper in a previous unit
5. Insufficient nip pressure
Adjust indentation value, repack
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Piling
1. Ink tack too high
Use ink with lower tack or modify
2. Coating containing (excess moisture)
Reduce water on previous unit
3. Insufficient nip pressure
Adjust indentation value
4. Unsuitable paper
Change paper quality
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Blanket delamination
1. Dry ink accumulation
Increase water supply to blanket surface
2. Ink accumulation on outside edges
Reduce width of blanket underpacking to minimum possible
3. Too high indentation
Reduce packing
4. Swollen packing and blanket
Change underpacking, avoid solvent penetration under
blanket
5. Plate edge cutting in blankets
Remove burrs
6. Unsealed blanket edges
Ensure edge sealing
7. Damaged blanket surface
Avoid blanket surface destruction
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Paper edge marking
1. Sharp edges of print stock
Keep packing smaller than stock
2. Coating and fiber accumulation
Keep blankets clean
3. Cutting knife of cutting machine
Change knife
4. Low compressible blanket
Change blanket quality
5. Too high nip pressure
Adjust indentation value
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Poor solids
1. Ink/water balance too high
Reduce balance
2. Indentation values too low
Adjust value, increase packing
3. Uneven packing
Use calibrated underpacking
4. Too soft underpacking
Use polyester foil or hard packing
5. Old or smashed blankets
Replace blankets or underpacking
6. Talc remnants on surface of blanket
Run a few sheets without water and clean blanket thoroughly
7. Ink roller adjustment
Ensure proper adjustment
8. Ink tack too high
Reduce tack
9. Destroyed print surface of plate
Change plate
10. Improper ink sequence
Change sequence
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Gauge loss
1. Blanket tension too high
Reduce tension according to recommendation
2. Unsuitable blanket quality
Change blanket quality
3. Too much nip pressure
Reduce indentation values
4. Ink and paper mist accumulation
Try to keep blanket clean
5. Mechanical conditions of press
Try blanket with high packing latitude
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Poor sheet release
1. Ink tack too high
Reduce tack
2. Untrue rolling conditions
Synchronize cylinder speeds
3. Surface swelling of blanket
Use less aggressive solvents
4. Ink too “fast”
Use “slower” ink
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Excessive plate wear
1. Indentation value too high
Readjust to recommendation
2. Untrue rolling conditions
Synchronize cylinder speeds
3. Blanket too hard
Use blanket with different value
4. Ink too “dry”
Contact ink manufacturer
5. Form roller setting too hard
Readjust form roller to plate
6. Developer too aggressive
Recheck developer mixture
7. Acid value in dampening water too high
Readjust pH to 5 - 5.5
8. Wrong direction of blanket
Recheck proper blanket mounting
9. Excess moisture in packing
Recheck proper conditions of plate and blanket packing
10. Blanket too loose
Re-tension blanket
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Gapping of blankets on double-width
presses
1. Excess moisture on outside edges of blanket packing
Change either one or both and avoid blanket/packing
excess solvent
2. Too high indentation
Readjust value to recommendation
3. Blanket too loose
Retension blanket
4. Mechanical conditions
Use blanket with high packing latitude
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Paper
overfeed on web presses
1. Indentation value too high
Reduce value to recommendation
2. Unsuitable blanket characteristics
Use a more “neutral” blanket
3. Blanket too hard
Use blanket with higher compressibility
4. Mechanical conditions of press
Use blanket with different characteristics
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Relief structure on blanket surface
1. Excessive lint build-up in non-image area
Keep blankets cleaner, reduce dampening on previous
cylinders,
change paper quality
2. Excessive ink accumulation on blanket
Increase alcohol on previous units, check surface pH
of dampening water, keep blanket clean, reduce ink tack
3. Ink build-up on impression cylinder
Keep impression cylinder clean
4. Minerals in ink make surface swell
Use blanket of higher quality
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Blanket surface glazing
1. Remnants of paper coating
Use anti-glazing solvents daily, contact your paper
supplier
2. Additives in fountain solution
Contact your solution supplier
3. Oxidation
Avoid UV ray exposure
4. Untrue rolling conditions
Synchronize cylinder speeds
5. Ink drier additives
Avoid use of additives
6. Unsuitable solvents
Use only recommended cleaning solvents
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If you still have questions, which weren’t answered,
we would be really pleased to be given the opportunity
to answer those! Please contact
us and we’ll talk about them!
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