Fujifilm Dirasol 22 제품 데이터시트

All handling of Dirasol emulsions should be carried out in light
of low blue and ultra-violet content. A photographic safelight is
not essential, but it is advisable to use yellow or weak tungsten
illumination.
A useful form of light for the workroom is provided by gold
fluorescent tubes and daylight should be excluded or filtered by a
yellow lacquer coating or film applied over windows.

Dirasol diazo emulsions are supplied as a two pack system
consisting of:
1.  Coloured Emulsion

2.  Diazo Sensitiser

which should be mixed as follows:
i)   Part fill the sensitiser bottle with water to not less than 80%

of its total capacity and shake it until the sensitiser is fully
dissolved.

ii)   Add the sensitiser solution to the emulsion and thoroughly stir-

in with a plastic or wooden stirring stick. Ideally the emulsion
should be allowed to de-gas for one hour before use.

Degrease the mesh in automatic screen cleaning machines using
Xtend Prep 300 Sprayable Degreasing Concentrate or by hand
with Prep 102 Degreasing and Emulsifying Concentrate. When
degreasing by hand using Prep 102 wet the screen and apply
with a sponge or brush and then rub the mesh with a light circular
motion. Ensure that both sides of the screen are thoroughly
treated. Leave to stand for a few minutes and rinse with cold
water to remove all traces of Prep. The mesh must be dry before
coating with emulsion.

Fujifilm Coating Troughs have been designed for the accurate and
consistent coating of direct photostencil emulsions. The troughs
are composed of precision extruded aluminium channelling fitted
with injection moulded end pieces. The aluminium channelling
of the troughs has a hard anodised finish which effectively seals
the surface. This feature makes the troughs easier to clean and
also protects them from corrosion. The end pieces have a special
shoulder which ensures that the coating edge is consistently at
the optimum angle in relation to the screen. To help eliminate
the beads formed at the extremities of conventional troughs,
special slots have been incorporated into the end pieces. These
features permit even relatively inexperienced operators to coat
screens faster and more consistently. Fujifilm Coating Troughs
are designed to deposit medium coating thicknesses. It is
therefore possible to coat a screen up to a given stencil thickness

with fewer strokes than would be required with a sharper or less
precise edge.

When using an automatic coating machine, apply a simultaneous
single coat to each side of the screen, followed by a second coat
to the squeegee side. If a higher build is required, extra coats
should be applied to the squeegee side of the screen.

Stand the screen on edge slightly inclined away from the operator
and process the screen as follows:
Apply one or two coats, wet on wet, on the print side of the
screen and then apply extra coats on the squeegee side of the
screen depending on the stencil build required.

Stand the screen on edge, slightly inclined away from the
operator, and process the screen as follows:

1.   Apply one or more coats wet on wet on the print side of the

screen to fill the mesh, the thickness of the finished stencil
being controlled by the mesh grade.

2.   A scrape coat to improve cosmetic appearance may be

applied on the squeegee side.

Coating from both sides is neither necessary nor desirable as
this can entrap air bubbles, giving rise to weak spots. This is
especially likely with monofilament meshes coarser than 43.80.

Dry the screen in a horizontal position, squeegee side up,
in darkness or subdued yellow light. A warm air fan or well
ventilated heated cupboard (up to 40°C) may be used but care
should be taken not to blow dust on to the drying screen. Dirasol
screens may be stored in the dark at cool temperatures prior to
exposure. See paragraph ‘Storage’ for recommended maximum
period.

Correct exposure is most important to obtain optimum
resolution, definition and stencil life. To establish this, with an
unfamiliar emulsion or light source, the use of an exposure test
scale is recommended.  
This can be done by:

1.  Using an exposure calculator.

2.   Placing a fine detail positive film over a coated screen and

giving it a series of stepped exposures using a black paper
mask.  
The exposure time is usually doubled from one step to the
next. The correct exposure is the longest exposure that can
be given whilst still obtaining optimum stencil resolution and
definition after wash out. Over-exposed areas would result in
loss of detail, whilst under-exposed areas may result in weak,
thin stencils.

  Position the positive, emulsion side in contact with the Dirasol

coating, on the underside of the dry screen, securing with
tape. Then place the complete screen into the vacuum print
down frame and ensure perfect contact before exposing
to light. The length of exposure time depends on the light
source, the thickness of the Dirasol coating, the fineness and
colour of the mesh, and the transparency of the background
of the positive. The following guide can be the basis of an
initial test exposure.

50 Amp Open Carbon Arc at 120cm

1330-1420  665-810  720-840  1080-1200 1500-1800  450-510

HPR 125W Mercury Vapour Lamp at 50cm

740-860  370-430  360-440  630-730  830-970  230-285

Metal Halide Lamps at 120cm
1000W

740-860  370-430  360-440  630-730  830-970  230-285

2000W

360-440  180-220  180-220  310-370  410-490  115-145

3000W

240-300  120-150  110-150  210-250  270-330  70-90

5000W

140-180

70-90

70-90

120-160  160-200  45-55

6000W

110-150

55-75

60-80

90-130

130-170  50-70