|
Problem
|
Description
|
Cause
|
Advice
|
Foils
|
|
Air Entrapment
|
Irregular and various holes that appear
on a job. They are always towards the middle of the foiled area and never
on the edge.
|
Generally caused by the surface of the
substrate being impervious and not allowing the air caught between the
foil and the substrate (particularly laminate) to escape. It therefore
bursts through the foil
|
Reduce the heat, or use a softer release
foil, or run the job on a cylinder press which will squeeze the air out.
|
XL, PH, UV, MF.
LA
AMY
|
|
Blooming/ Rainbow Lines
|
Lines of distortion or "rainbow" effects
appear in the printed foil.
|
Temperature is too high, causing the foil
to warp or distort under the heat.
|
Reduce temperature, dwell or increase
speed.
|
Some foils have a heat resistant lacquer.
i.e. 6010LF or LA10
|
|
Corrosion / Oxidation
|
The foil changes from bright metallic
to dull, or gold to silver, or completely disappears a short time after
foiling. (6hrs to 2/3 weeks)
|
The combination of aluminium in the foil,
and amines (carbon humidity, and heat) in the ink, substrate or atmosphere.
This causes an Oxidation of the aluminium.
|
No cure, only prevention. Make sure the
board/ink is dry, and the combination of amines is not created.
|
Most foils are vulnerable
to this.
|
|
Gassing/Blistering
|
Irregular and various holes that
appear on a job. They are always towards the middle of the foiled area
and never on the edge.
|
Generally caused by the surface of the
substrate reacting with the heat of the die and a gas resulting. This Gas
cannot escape and bursts through the foil.
|
Reduce the heat, or use a softer release
foil, or run the job on a cylinder press which will squeeze the gas out.
|
MF, PH, UV, XL
AMY
|
|
Matting off
|
Normally after exposed to a lazor printer.
Foil dulls and starts to come off.
|
Lazor temperature is too high for foil.
|
Use a lazor resistant foil.
|
LA10
6010LA
|
|
Missing
|
Partial image is missing. Tending to be
the edge, particularly text.
|
Incompatibility of the foil and substrate.
|
Change the foil. Some adjustments in the
make ready can resolve some problems. i.e. packing under the make ready
where the missing occurs.
|
ABG, MF, UV, JD.
AMY
|
|
No Impression
|
No foil or only small bits of foil are
transferring.
|
1) Foil not suitable
2) Machine heater not turned on (it happens!)
3) Substrate is not blockable
|
T1) Change Foil
2) Turn machine on.
3) Treat surface to be printed.(ie Chorona
Treatment)
|
n/a
|
Offset/ Set off
|
Speckles of foil sticking to the
substrate above or next to it when stacked. Most often seen when a tacky
varnish is on the substrate.
|
It is caused by the ink/varnish, which
may not be fully cured, or is too foil friendly so as to attract any excess
foil transferred in blocking.
|
Fully cure the substrate. Use a clean
release foil, reduce machine pressure (a cylinder may help) reduce
temperature, or wipe the sheets prior to stacking.
|
ABX
ATK
AMY
|
Over
Printability
An example of a printed holographic
foil.
|
The ink varnish or another foil to adhere
properly onto the foil
|
All foils have a wax release coat to assist
them to release. This makes overprinting difficult
|
Special Printable foils help, but it may
also need some adjustment to the inks
|
Silver
PXL
Holographic
BU84 BD84
|
|
Picking
|
1) Lifting off of foil in small areas
during another process (i.e. overprinting)
2) Small areas of non transfer during foiling.
|
1) The foil is pulled off by the tackiness
of the inks and sticks to the print blanket.
2) The foil adhesive is not thick enough to
"grab" the substrate, or the release is too tight.
|
1) Use a cleaner foil, or thin the inks,
or reduce pressure of the machine.
2) Use a softer release or heavier adhesive
foil or build up the make ready.
|
MF, PH, UV.
AMY
|
|
Pin holing
|
A hole which appears in the foil. This
can be seen prior to using the foil when held up to the light. Sometimes
used when Gassing is a more accurate description.
|
A fault in foil manufacture, caused by
the metaliser "spitting" in production. Should be spotted prior to foiling.
|
Try an alternative "batch" of foil.
|
n/a
|
|
Plasticisor Migration
|
Only with PVC.
The Foil appears to have "smudged" some time after foiling. Metallics
"dull".
|
The plasticisor in the PVC migrates to the surface and attacks
the foil.
|
Use a foil resistant to Plasticisor.
|
PV
|
|
Rejecting
|
A jagged edge appears to the foiled area.
|
In compatibility between foil and substrate.
The foil cannot key.
|
Change the foil.
|
Dependent on the surface. See "Substrates"
|
|
Silvering
|
The evidence of silver showing through
a metallic colour.
|
The coloured lacquer can shatter when
"Blocked" to show the silver aluminiun underneath.
|
Try to lessen the impact by using less
pressure.
|
UV
|
|
Smudging
|
Foil appears to bleed into surround area
some time after foiling.
|
Reaction between foil and the substrate
or a material put on top. (i.e. lamination)
|
Change the offending material or substrate, or use a foil with
a barrier coat. (Tests will be needed.)
|
BA
|
|
Sticking
|
The Foil is "sticking" to the substrate.
|
The Temperature is too High or too Low.
|
Raise or lower the temperature. If image
is lost, change the foil.
|
n/a
|
| |
|
|
.
|
|
|
|
|
|
|
