|
PROBLEM |
CAUSE |
SOLUTION |
| TINTING/TONING:
Adhesion of ink
to non-image area of the plate
|
1.Ink
too thin.
2.Improper fountain
solution concentration
3.Ink and dampening
rollers set too tight to plate
4.Ink is taking
on too much water and breaking down.
5.Non-image area
of plate has become sensitized and ink receptive.
|
1.Use
ink with more body.Consult ink supplier..
2.Check fountain
solution by conductivity to ensure the correct
dosage.
3.Reset to lighter
pressure to avoid "grinding"pigment into
the plate surface
4.Consult with
ink and fountain suppliers
5.Use plate cleaner,if
toning returns remake plate and check fount
strength.
|
| SET-OFF: |
1.Too
much ink on the paper.
2.Ink is too
stiff and will not penetrate into the paper.
3.Paper is not
porous enough.
|
1.Use
less ink or switch to a more concentrated
ink.
2.Reduce ink
viscosity or change ink.
3.Consult paper
and ink supplier.
|
| HICKIES:
White spots surrounding
a small spot.
|
1.Particles
of dried ink.
2.Paper dust.
3.Dust from overhead
objects(lights,
ceiling…)
|
1.Clean
rollers and ink fountain.
2.consult paper
supplier.
3.Clean all overhead
objects in the work area.
|
| MISTING/SPITTING:
Misting-fine
droplets of ink thrown from ink rollers
Spitting-ink
being thrown from
Rollers in filaments
|
1.Too
much ink on rollers.
2.Ink too thin.
3.Press speed
too high.
4.Improper ink/water
balance.
5.Inking rollers
are incorectly set or damaged.
6.Roller train
is too hot.
|
1.Reduce
ink film or use stronger ink.
2.Use ink with
more body.Cosult inksupplier.
3.Reduce speed
of press.
4.Reduce ink
setting and then water to lower point of
ink/water balance.
5.Reset rollers
and replace damaged rollers.
6.Increase flow
of cooling water.
|
| PILING:
Build-up of paper
fibres or ink on rollers,blankets or plates.
.
|
PAPER:
1.Paper dust.
INK:
1.Ink is over-emulsified.
2.Blanket tack
is too high.
3.Ink is too
stiff or too tacky.
MECHANICAL:
1.Improper packing
of cylinders or rollers not set correctly.
|
PAPER
:
1.Try washing
it away by increasing water feed.
INK :
1.Consult ink
and fountain solution suppliers to reduce
water take-up of ink.
2.Run more water
or add non-piling additive.
3.Consult ink
supplier.
MECHANICAL :
1.Adjust settings.
|
| PICKING:
Pulling fibres from
uncoated or coating from coated papers.
|
1.Poor
quality paper.
2.Impression
cylinder pressure too high.
3.Blanket is
too tacky.
4.Ink too tacky
for paper .
|
1.Change
to a better quality paper with better pick
resistance.
2.Reduce impression
pressure.
3.Ensure that
blanket is washed completely and not tacky
after wash cycle.
4.Consult ink
supplier.
|
