Fujifilm Dirasol CTS Product Datasheet (en)

Dirasol CTS Photopolymer Emulsions
Product Information
Dirasol CTS is a pre-sensitised photostencil emulsion designed to
offer the optimum exposure speed on direct-to-screen stencil
systems. Dirasol CTS is formulated for use with solvent based,
100% UV, and water-based UV inks. Please note post exposure
may be required when printing with water-based UV inks.
Dirasol CTS
One pot system, ultra-fast exposure speed, easy de-coatability, 
with resistance to solvent-based, 100% UV, water-based UV inks.
Please note post exposure may be required when printing with 
water-based UV inks.
Instructions for Use
Dirasol photopolymer emulsions are pre-sensitised, and therefore
sensitive to light at all times. All handling of Dirasol emulsions should
be carried out in light which is low in blue and ultra-violet content. A
photographic safelight is not essential but yellow or weak tungsten
illumination is recommended. A useful form of light for the workroom
is provided by gold fluorescent tubes. Daylight should be excluded or
filtered by a yellow lacquer coating or film applied over windows.
Coated screens should be stored in total darkness.
Preparing the Screen
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.
Allow the mesh to dry before coating.
Automatic Coating
One simultaneous single coat on each side of the screen is
recommended, followed by further coats on the squeegee side if
required to increase build.
Hand coating:
Apply 1 coat on the print side of the screen and then apply one coat
or more wet-on-wet on the squeegee side. The Sericol Coating Trough
is particularly recommended.
Sericol Coating Troughs
The troughs are composed of precision extruded aluminium
channelling fitted with injection moulded end pieces for accurate and
consistent coating of photostencil emulsions. The channelling has a
hard anodised finish which effectively seals the surface, easing
cleaning and protecting from corrosion. The ends have a special
shoulder and slots incorporated, ensuring the coating edge is
consistently at the optimum angle to the screen helping eliminate
beads. These features permit relatively inexperienced operators to
coat screens faster and more accurately. Designed to deposit medium
coating thicknesses, it is possible to coat a screen to a given stencil
thickness with fewer strokes than would be required with a sharper or
less precise edge.
The wet screen must be dried in darkness or subdued yellow light,
ideally in a horizontal position, squeegee side up. 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. 
For maximum stencil durability the screen must be thoroughly dry
before exposure.
Correct exposure is most important to obtain optimum resolution,
definition and stencil life. For this reason it must be determined by
exposing a tone test strip for a range of exposure speeds. For a
durable stencil, the ideal time is the maximum exposure to achieve
optimum resolution. If necessary repeat with smaller speed intervals to
determine exposure more accurately.
Post exposure In order to increase the water resistance properties of
the emulsion, post exposure is recommended.
Factors Affecting Exposure speed:
Age of lamp in Direct Light Exposure machine
The lamp systems in DLE machines (also referred to as Digital Mirror
Devices DMD) are known to reduce in power with time. Care should
therefore be taken to calibrate the lamp on each machine prior to
conducting emulsion exposure tests. For more details on power
mapping of DLE lamps contact the DLE machine manufacturer.
Mesh colour
The increased light absorption of coloured mesh will significantly
increase the exposure time of Dirasol CTS. For optimum exposure time
White mesh is therefore recommended.  
Gently spray both sides of the screen with cold or warm water 
(not above 40°C). For best results, an automated screen developing
unit is recommended.
Final Drying and Spotting
Dry with the aid of a fan. Any small blemish or pinholes can be filled in
using Universal Filler (FISW1) or emulsion which requires re-exposure.
Reclaiming the Screen
Automatic Screen Cleaning Machines:
Remove ink residues using an Xtend Screen Cleaner and de-coat
stencil using diluted Strip Liquid Concentrate.
Manual Screen Cleaning:
Remove ink residues using a wiper soaked with an Xtend Screen
Cleaner. Rinse the screen with water and then apply diluted Strip
Powder or Strip Liquid to both sides of the stencil. Leave for a few
minutes. The stencil can then be easily removed with a strong water
jet or high pressure water gun.