Ultrasonic Removal of Contaminants from BK-7
Glass Using SP2275

I. Purpose

The purpose of the test was to evaluate the efficiency of the ultrasonic removal of contaminants from BK-7 glass using VALTRON^® SP2275 neutral detergent.

II. Parameters of the Experiment

1. Conditioning of the Substrates:
   Five (5) pieces of degreased BK-7 glass with contaminants were submitted by the customer for evaluation.  No further conditioning was necessary.
2. Preparation of Detergent Solutions:
   2% VALTRON^® SP2275 neutral detergent
   
   200mL of the above detergent solution was prepared in a 250mL stainless steel beaker. The detergent solution was degassed for 15 minutes at a temperature of 120°F/49°C in a Blackstone Ney^® ultrasonic unit operating at 40 kHz and 100% power.

III. The Experiment

1. 200mL of 2% VALTRON^® SP2275 was prepared in a 250mL stainless steel beaker. The beaker was placed into a Blackstone Ney^® ultrasonic unit operating at 40 kHz and 100% power and degassed for 15 minutes at 120°F/49°C.
2. A BK-7 glass substrate was suspended in the detergent solution and ultrasonically washed for 2 minutes at 120˚F/49˚C.
3. The substrate was removed from the ultrasonic wash tank and given a 15-second spray rinse of low-pressure deionized water at room temperature.
4. Next, the substrate was vertically suspended in deionized water and ultrasonically rinsed for 2 minutes at 120°F/49°C.
5. The substrate was removed from the ultrasonic rinse tank and given a 15-second spray rinse of low-pressure deionized water at room temperature.
6. The substrate was allowed to dry and then examined under a high-intensity light source for any microcrazing.
7. Then, the substrate was allowed to air dry and inspected under the 30X magnification of a Leica^® Stereo Zoom 4 microscope for any remaining contamination.
8. The results are summarized in Table 1.

IV. Results

Table 1: Compatibility Testing of Polarized Polycarbonate Lenses with VALTRON Detergents

V. Conclusion

The contamination was easily removed from the BK-7 glass using a 2% solution of VALTRON^® SP2275 when ultrasonically washed for 2 minutes at 120°F/49°C.

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