| Problem |
Possible Cause |
Remedies |
| General
set-off | Insufficient
powder used Too fine a grade of powder Too
much ink carried Incorrect ink/water
balance Stack too high |
Increase amount of spray powder Change
to a larger micron size Reduce ink film
and use stronger ink Consult ink and/or
chemistry supplier Use smaller stacks |
| Uneven
stack | Too
much powder being applied Too fine a
grade causing the above | Reduce
powder applied Increase micron size of
powder and reduce quantity |
|
Powder building up on blanket on subsequent passes |
Too much powder being applied Incorrect
type of powder being used |
Use a coated powder and increase micron size of
powder to prevent overspraying Change
to soluble powder which dissolves on the blanket |
| Lamination
lifting from the substrate | Excessive
use of powder Insufficient cleaning of
sheets
Incorrect powder
|
Reduce powder usage Use
a soluble powder and clean sheet with only damping engaged Try
coated powder |
|
Loss of gloss after U.V. varnishing |
Excessive use of powder |
Reduce powder usage Use
soluble powder and clean sheet with damping engage in line or off line |
| Rough
finish | Too
much powder being applied | Reduce
powder usage Increase micron size of
powder to create better separation with less powder |
| Powder
‘flying about’ and soiling the press room |
Overspraying with a fine powder
Excessive
air turbulence at the delivery
|
Use a larger micron powder to reduce quantity Change
to the S88 range of highly graded powders |
