Trial #27
To evaluate the effectiveness of SB-27 (t-Butyl Acetate 70% (CAS No: 540-88-5) + Benzyl Alcohol 30% (CAS No: 100-51-6)) and SB-32 (Ethyl Lactate 81% (CAS No: 97-64-3) + Propylene Carbonate 19% (CAS No: 108-32-7)) in removing greases from stainless steel coupons as a potential replacement of TCE with a heated ultrasonic cleaning method.
Three stainless steel coupons were used for each cleaner and soil combination, making a total of twelve coupons. The initial weights of each coupon were recorded. Around 0.1 g of each contaminant was added to the bottom third of the coupon with a swab, and the dirty weights of each coupon were then recorded. The coupons were then subjected to heated ultrasonics in the cleaner for 15 minutes at a temperature of 120 °F. After the coupons were cleaned, they were left to air dry over night, and clean weights of each coupon were taken the following day.
| Cleaner
|
Soil
|
Initial weight of cont.
|
Final weight of cont.
|
% Content Removed
|
Average % Removal
|
| SB-27
|
DAW 330B
|
0.0761
|
0.0664
|
12.75
|
-21.63
|
| 0.0420
|
0.0550
|
-30.95
|
| 0.0863
|
0.1266
|
-46.70
|
| Slide Gel No. 7
|
0.0523
|
0.0106
|
79.73
|
62.48
|
| 0.0407
|
0.0102
|
74.94
|
| 0.0476
|
0.0320
|
32.77
|
| SB-32
|
DAW 330B
|
0.0188
|
0.0007
|
96.28
|
91.95
|
| 0.0254
|
0.0027
|
89.37
|
| 0.0286
|
0.0028
|
90.21
|
| Slide Gel No. 7
|
0.0409
|
0.0087
|
78.73
|
83.02
|
| 0.0355
|
0.0066
|
81.41
|
| 0.0334
|
0.0037
|
88.92
|
Overall, the cleaners were not effective in removing the contaminants, but the only one that worked well enough was SB-32 on DAW 330B. When taking the coupons out of the cleaner, thick clumps of soil clung together and slipped right off the coupons. For the coupons in SB-27, the soil clung together the same way, but it was still attached to the coupon when I took them out, and they even seemed to absorb some of the cleaner and make the averages negative.
No relation