SP 9500 DUAL CURE DIRECT EMULSION 

SP-9500 is a diazo/photopolymer (dual cure) type emulsion designed to be compatible with both solvent and water based systems.

• Excellent for use with water thinnable U. V. and water based graphics inks.
  
• Entirely suitable for use with conventional U.V. inks, textile printing and commercial applications.
  
• Exhibits outstanding resolution and definition qualities while offering high abrasion resistance.
  
• Has solids content of 37% (sensitized), is extremely resistant to humidity.

MESH PREPARATION

It is extremely important to clean and degrease the screen mesh prior to each application of SP-9500. Oils and grease from transportation or storage, residual contamination from inks and cleaning chemicals and general shop dirt can greatly interfere with consistent, smooth coating and increase the chances of stencil breakdown later on.

Ink stains on the mesh can be removed with Murakami's 701 Haze/Ghost Remover. This non-caustic, water soluble liquid is specially formulated for use with all types of inks. Murakami's 801 Degreaser helps eliminate the problems caused by screen mesh contaminants on all types of fabric. It safely controls water hardness and cleans unwanted residue such as oils, grease, dirt and dust.

The screen should be rinsed well with water and allowed to dry completely before proceeding with coating.

SENSITIZING

Diazo sensitizer is supplied with each container of SP-9500. Add water to 3/4 of a bottle full, replace the cap and shake well to dissolve the diazo. After the diazo is completely dissolved, pour the mixture into the emulsion. (Use a small piece of screen printing mesh as a filter to eliminate any undissolved diazo particles while adding the diazo solution.) Stir well for 10 minutes to thoroughly disperse the diazo into the emulsion. Cover and let the sensitized emulsion stand for 2 hours to allow air bubbles to disappear.

COATING

The use of a sharp edged coater is preferred, unless the coating is required to be thick, such as on a 110 mesh or under.

A. Using a clean, dry coater, apply one coat of SP-9500 to the print side of the screen. Rotate the screen 180 degrees and apply one coat of SP-9500 to the squeegee side.

B. For optimal build up on coarse meshes (110 and under), apply one coat of SP-9500 to the print side and one coat to the squeegee side. Allow the screen to dry print side down. Then apply 2-3 very thin coats to the print side to build to the desired thickness, if necessary.

DRYING

Dry the coated screen in a clean, light safe area in a horizontal position print side down. Thorough drying of the coated screen is very important. The following conditions will help facilitate and insure complete drying:

86 to 104 degrees F (30 to 35 degrees C

30% to 40% Relative Humidity

Air ventilation i.e. fan essential

An enclosed screen drying cabinet with heated airflow is very helpful in obtaining and sustaining these conditions, as well as keeping your screens,free of contamination.

EXPOSURE

The following exposure table should be regarded as guideline only. The use of the Murakami CSC Exposure Scale is recommended to determine the proper exposure time.

EXPOSURE TABLE

All exposure times listed below are established using a 5000W metal halide lamp at 40", 15.5 mW/cm2 output below the vacuum glass. Nanometers of spectral peak output: 360-410 nm.

Note: It is very important that your exposure is performer with a light source that was specifically developed for screen printing. Exposure time can vary depending on the nanometer output of the light and distance from the vacuum frame.

WASHOUT

The image should be washed out using a cold water spray. Wet the stencil completely on both sides. Let it stand for 30 seconds. Wash the image area from the print side until it is clear of unexposed emulsion. Turn the screen around and rinse the squeegee side to remove any residual unexposed emulsion. Blot the screen and frame with a chamois to remove any excess water. Dry the screen in a horizontal position.

RECLAIMING

Scrape all excess ink from the screen. Remove ink residue with a suitable solvent. Flush the screen with water. Apply Murakami 601 Emulsion Remover or Strip Super-P to both sides of the stencil and allow to sit for 30 seconds to 1 minute. (Do not allow any stencil remover to dry on your screen.) Use a high pressure washer to remove all stencil residue from the mesh.

STORAGE AND HANDLING

In an unsensitized state, SP-9500 should be stored in a cool (under 70 degrees) and dry area. After sensitizing, the emulsion kept under the same conditions has a shelf life of approximately 2 months.

COATED SCREENS

Coated screens have a shelf life of up to one month when kept under the following conditions (in a light safe area):

59 to 77 degrees F (15 to 25 degrees C)

40% to 50% Relative Humidity

We also recommend that an exposed coated screen that has been stored under the above conditions over 2 hours be placed in a drying cabinet for a few minutes prior to exposure.

EXTREME PERFORMANCE REQUIREMENTS

Murakami also provides Hardener A & B. Hardener A & B is a two part system for chemically hardening SP-9500 in making stencils extremely water resistant for long production runs. Stencils treated with Hardener A & B will be permanent and will not he reclaimable