|
Temporary
Lamination
Holography materials
certified and distributed by Geola are manufactured on glass and
TAC film substrates.
The temporary film
lamination technique described below is an alternative to the
well-known index matching technique and is easier and less
time-consuming. The technique is appropriate for film sheets of
20x30cm or larger.
We recommend using an
electrostatic transparent film similar to the 5105CL "Penstic"
Transparent film from Molco GmbH www.molco.com,
Germany. The procedure is as follows.
1. Clean a glass plate
and place it horizontally. The plate should be slightly bigger
than the actual film.
2. With a soft brush
create an electrostatic charge on the glass plate.
3. Apply the
electrostatic film to the glass plate with a (photographic) rubber
roller making sure that you eliminate all the air bubbles.
4. Again take a soft
brush and create an electrostatic charge on the electrostatic
film.
5. Apply the holographic
film to the electrostatic film with the rubber roller making sure,
once again, that you eliminate all the bubbles.
6. Now use the glass
plate as you would a normal holographic plate.
7. After making an
exposure (and latensification) simply peel off your photosensitive
film and process
it as described above.
Another technique useful to achieve the
necessary flatness for the recording of film holograms smaller
than 20x30cm is to put the film between two glass plates.
Final
Lamination
The emulsion of
holograms made on film and glass plates should be protected from
humidity and UV light. The diffusion of water into the emulsion
leads to the colour of the hologram changing. UV radiation causes
hologram brightness degradation (the "print out"
effect). In order to protect the hologram from these unwanted
effects one may cover and seal the hologram on one or both faces.
In the case of glass holograms
sealing from the back side is sufficient whereas film holograms
should be sealed both from the front and the back.
The
best way to protect the back side (the emulsion) of reflection
holograms is by lamination of a black self-adhesive film. We
recomend “Black Oracal” 641-070M from Orafol GmbH, Germany http://www.orafol.de/
, or a similar product. It is straight-forward to apply this black
film to the emulsion side of the hologram using a photographic
rubber roller. Alternatively a cold lamination machine may be
used. The result is a sandwich consisting of the holographic
substrate, the emulsion and the protective film.
For
emulsion protection of transmission film holograms we recomend the
use of a transparent double-sided self-adhesive film (e.g.
Optimount 60238 from Hunt Graphics Europe Ltd.) and a plexiglass
sheet (e.g. Plexiglas XT, from Rohm GmbH, Germany, http://www.roem.de/
).
One
side of the double-sided film is applied to the emulsion side of
the hologram and the other side is stuck to the plexiglass. This
can be done either by hand (rubber roller) or by using a cold
lamination machine. The result is a sandwich consisting of
holofilm substrate, emulsion, adhesive and plexiglass.
In
order to insure flatness of film reflection holograms the same
technique of mounting to a plexiglass sheet using a doublesided
film may be used. The result is a sandwich consisting of the film
substrate, the emulsion, a black self-adhesive film, the
double-sided self-adhesive film and finally the plexiglass sheet.
Front-side
protection of the hologram from UV radiation can be effected by
use of the standard UV reflecting films available from Edmond
Scientific( http://www.edsci.com/
). |