|
PROBLEM
|
CAUSE
|
SOLUTION
|
| Tinting
- scumming |
1)
Ink too thin
2) Fountain solution
is too acid
3) Incorrect
ink/water balance
4) Plate incorrectly
processed
|
1)
Use an ink with more body (seek assistance
from TRENAL)
2) Measure the
pH of the fountain solution. If the pH is
not between 5,0 and 5,5, re-adjust the fountain
solution.
3) Clean up ,
and correctly re-adjust the ink and water.
4) Prepare and
use a new printing plate
|
SET-OFF
in the delivery pile |
1)
Too much ink on the paper
2) Fountain solution
is too acid
3) Ink doen not
contain enough driers
4) Ink is too
stiff;doesn’t penetrate into paper
5) Poor quality
paper coating
6) Delivery pile
is too high
7) Static electricity
in pile is causing sheets to stick together
|
1)
Use less ink, or a more concentrated ink
2) Re-adjust
fountain solution to a pH of 5,0 - 5,5
3) Add GRAFO-DRIER
to ink
4) Reduce the
ink viscosity with a suitable reducer
5) Change paper
for a better quality paper
6) Reduce pile
height, and print smaller piles
7) Use a static
eliminator
|
| Hickies |
1)
Particles of dried ink or skin from ink can
2) Paper dust
3) Dust from
overhead objects e.g. lights
|
1)
Remove all skin or hard particles from ink
before putting ink
into duct
2) Remove paper
dust before running (clean edges of stack)
3) Clean all
overhead objects in the work area
|
Misting
Ink flies
off into admosphere of work place as a fine
mist. |
1)
Ink too thin
2) Press speed
too high
3) Inking rollers
are old and damaged
4) Too much ink
|
1)
Use an ink with more body (seek assistance
from TRENAL)
2) Reduce press
speed
3) Inspect rollers
and replace damaged rollers
4) Reduce the
ink film
|
| Slow
drying of ink on paper |
1)
Fountain solution too acid
2) Paper too
acid
3) Insufficiant
driers in ink
4) Ink not suitable
for the type of paper
|
1)
Re-adjust fountain solution to give a pH of
5,0 - 5,5
2) Replace paper
with a different grade and more neutral
pH
3) Add GRAFO-DRIER
to ink
4) Contact TRENAL
for technical assistance
|
| Poor
distribution of ink on paper |
1)
Ink too stiff or tacky
2) Ink rollers
are old and damaged
3) Ink rollers
are glazed
|
1)
Add GRAFO-GEL to ink
2) Inspect rollers
and replace damaged rollers
3) Remove glaze
from rollers with TRENAL DEGLAZER
|
| Piling
on ink rollers |
1)
Ink too stiff or tacky
2) Ink has become
emulsified with water
|
1)
Add GRAFO-GEL to ink
2) Add WATER
RESISTANT VARNISH V.950
|
| Drying
of ink on rollers |
1)
Too much drier in ink
2) Incorrect
type of ink for work being printed
|
1)
Reduce the driers in ink
2) Contact TRENAL
for technical assistance
|
| Picking
of paper |
1)
Ink too tacky
2) Impression
cylinder pressure too high
3) Poor quality
paper
|
1)
Add GRAFO-GEL to ink
2) Adjust and
reduce impression cylinder pressure
3) Change to
a better quality paper with higher pick
resistance
|
