The two products from the previous trial were heated to 110 F on a hot plate. A third product was included for testing. Nine preweighed ceramic coupons were coated with client supplied lacquer, Microshield Stop Off (78-93-3, 108-88-3, 109-99-9, 75-56-9, 842-07-9). The contaminant was applied directly to the coupon surface using a swab. The coupons were allowed to dry at room temperature before weighing a second time. Three coupons were cleaned in each solution for 10 minute intervals, up to 30 minutes, using stir-bar agitation. Coupons were rinsed in tap water for 15 seconds at 120 F, followed by air blow off at room temperature. Once dry, coupons were weighed a final time and efficiencies for each cleaner were calculated.
The DuPont DBE 6 was successful after 20 minutes of immersion cleaning, removing over 94% of the Stop Off from the coupons. The Vertec Ink Zapper removed around 50% of the paint after 30 minutes. Visual observations noted that this cleaner could be improved with additional mechanical energy. The Metabolix E3HB again showed positive dissolving of the contaminant but resulted in an increase in weight. The cleaning solution would also benefit from additional mechanical energy.
| Cleaner
|
Initial wt
|
Final wt
|
% Removed
|
| E3HB at 30 minutes
|
0.1046
|
0.1300
|
-24.28
|
|
|
0.1191
|
0.1779
|
-49.37
|
|
|
0.1189
|
0.1802
|
-51.56
|
| DBE 6 at 20 minutes
|
0.0398
|
0.0048
|
87.94
|
|
|
0.0667
|
0.0015
|
97.75
|
|
|
0.0692
|
0.0025
|
96.39
|
| Ink Zapper at 30 minutes
|
0.0719
|
0.0347
|
51.74
|
|
|
0.1078
|
0.0419
|
61.13
|
|
|
0.0705
|
0.0291
|
58.72
|