Ulano FX-88 SR Diazo Emulsion
IMPORTANT: Texsource ships in-stock items as orders are placed, and cannot guarantee that temperature-sensitive items, like emulsions and emulsion removers, will not be exposed to freezing temperatures in transit. Texsource is not responsible for items damaged by exposure to extreme temperatures.
FX88-SR exposes in about half the time of normal diazo-sensitized emulsions and produces tough stencils with good resolution and edge definition and can be reclaimed easily.
FX88-SR is undyed (for easier see-through registration; color additive supplied separately) and is totally solvent-resistant. Ideal for use with low-intensity light sources, because of its short exposure time. Supplied with pre-measured diazo sensitizer in powder form.
Step 1: PREPARE THE MESH
Used or surface-treated mesh need only be degreased using Screen Degreaser Liquid No. 3 or dilute Screen Degreaser Concentrate No. 33. (Mechanical abrasion is an option for new mesh that is not surface treated. It increases the surface area of for a better mechanical bond of the stencil, increasing printing run length. Use Microgrit No. 2 before degreasing. Abrading and degreasing can be combined in one step with Ulanogel 23.)
Step 2: SENSITIZE THE EMULSION
Dissolve the diazo sensitizer by adding lukewarm water up to the shoulder of the diazo bottle. Shake it well. Wait 15 minutes for bubbles to disperse. Pour the fully dissolved sensitizer into the emulsion. Stir the emulsion with a clean, flat plastic or stainless steel instrument until it is uniform in color. Close the container. Wait at least one hour for the sensitized emulsion to de-bubble. Write the date of sensitizing on the label of the emulsion container.
Step 3: COAT THE SCREEN
- Method 1: Apply one coat of emulsion on the printing side, then one coat on the squeegee side. Dry the screen thoroughly.
- Method 2: Apply two coats on the printing side, then two coats on the squeegee side, wet-on-wet. After each coating, rotate the screen 180°. Dry the screen thoroughly, printing side down.
- Method 3: Follow Method 2 (above). Then, after drying the screen, apply two additional coats on the printing side, wet-on-wet. Dry the screen again.
Step 4: DRY THE SCREEN
Dry multicoated screens (Methods 2 or 3) thoroughly in a horizontal position, printing side down, at room temperature in a dirt- and dust-free area. Use a fan to speed drying. Avoid high humidity. Under humid conditions, dry the coated screen with warm, filtered air, up to 104° F. (40° C.) in a commercial dryer. Use a dehumidifier in the drying area, if possible.
Step 5: EXPOSE THE EMULSION
Select an exposure time from the Exposure Table below based on the type of light source you have and the coating method you use. Multiply the selected exposure time by all relevant exposure variables and distance factors to obtain an Approximate Exposure Time. Use the Ulano Exposure Calculator or make a Step Wedge Test to determine the optimum exposure. Optimum exposure is indicated when:
- No outline of the positive or darkening of the emulsion color is observable if the exposure is increased.
- The squeegee side emulsion is hard and not slimy.
- A print made from the stencil best duplicates test positive at the required level of resolution.
Step 6: WASH OUT THE EMULSION
Wet both sides of the screen with a gentle spray of cold water. Then spray forcefully from the printing side until the image areas clear. Rinse both sides with a gentle spray until no soft emulsion is left on the squeegee side, and no foam or bubbles remain. Blot excess water from the printing side with unprinted newspaper stock.
Step 7: BLOCKOUT & TOUCHUP
- Option 1: Before drying and exposure, use excess emulsion from the coating step to cover the blockout area. Blockout
- Option 2: After exposure and washout, dry the screen. Apply Screen Filler No. 60 or Extra Heavy Blockout No. 10.
- Option 1: Use excess emulsion and re-expose the screen. Touchup
- Option 2: Use Screen Filler No. 60 or Extra Heavy Blockout No. 10 thinned with water. Dry the screen.
Step 8: RECLAIM THE SCREEN
Remove the ink with the manufacturers' recommended solvent. Rinse with water. Degrease with Screen Degreaser Liquid No. 3 to remove oily ink and solvent residues. Rinse the screen. Brush Stencil Remover Liquid No. 4 or Stencil Remover Paste No. 5 on both sides of the screen. Do not let the stencil remover dry on the screen. Rinse gently, then use a forceful spray of water. Use Haze Remover Paste No. 78 to remove ink and haze and stencil scum residues, if necessary.
Unsensitized emulsion can be stored for up to 1 year. Sensitized emulsion can be stored for 3 – 6 weeks at room temperature; up to 3 months in a refrigerator. Store coated screens in a cool, dry, completely dark area until exposure.