Trial Purpose:
To evaluate the effectiveness of a FAME + Methyl Lactate mixture in removing several production oils and greases from stainless steel coupons as a potential replacement for TCE using unheated immersion.
Date Run:
03/22/2023Experiment Procedure:
Three stainless steel coupons were used for each of the five soils being tested for a total of 15 coupons. The initial weights of each coupon were recorded. The bottom third of every coupon was soiled by applying the corresponding soil with a swab. The dirty weights of each coupon were then recorded. The coupons were then subjected to unheated immersion cleaning in a solution of Fatty Acid Methyl Ester 93% + Ethyl Lactate 7% for 15 minutes, with a stir bar set to 200 rpm. After the coupons were cleaned, they were left to air dry overnight. The next morning, the clean weights of each coupon were taken.
| Soil | Use | CAS |
| Milform OAK 7a International | Stamping and drawing fluid | 64742-53-6 / 68909-65-9 |
| Milform Oak 529 | Evaporative lubricant | 68551-17-7 / 123-95-5 / 127087-87-0 |
| Milform Oak 15a | Metalworking oil | 64742-44-5 / 64742-52-5 / 64742-55-8 |
| Milform Oak 15c | Metalworking oil | 64742-52-5 / 64742-53-6 |
| M4 |
Trial Results:
| Solvent | Substrate | Soil | Initial wt of cont. | Final wt of cont. | %Cont Removed | % AVG | % Overall |
| Fatty Acid methyl ester 93% + Ethyl lactate 7% | Stainless Steel | Oak 7a international | 0.0617 | 0.0443 | 28.20 | 46.43 | 7.20 |
| Oak 7a international | 0.0718 | 0.0430 | 40.11 | ||||
| Oak 7a international | 0.0617 | 0.0179 | 70.99 | ||||
| M4 | 0.4885 | 0.0139 | 97.15 | 90.26 | |||
| M4 | 0.7935 | 0.1424 | 82.05 | ||||
| M4 | 0.7030 | 0.0592 | 91.58 | ||||
| Oak 15C | 0.0886 | 0.0604 | 31.83 | 15.74 | |||
| Oak 15C | 0.0836 | 0.0706 | 15.55 | ||||
| Oak 15C | -0.9347 | -0.9363 | -0.17 | ||||
| Oak 15A | 0.1667 | 0.0632 | 62.09 | 62.06 | |||
| Oak 15A | 0.1776 | 0.0821 | 53.77 | ||||
| Oak 15A | 0.1617 | 0.0480 | 70.32 | ||||
| Oak 529 | 0.0134 | 0.0708 | -428.36 | -178.51 | |||
| Oak 529 | 0.0075 | 0.0064 | 14.67 | ||||
| Oak 529 | 0.0197 | 0.0437 | -121.83 |
After being allowed to air dry over night, it was observed that the coupons were still completely wet the next morning. The FAME + Methyl Lactate solution was unable to air dry, which is reflected in these measurements. In some cases, a larger amount of cleaner remained on the coupon than the amount of soil it removed, leading to a heavier clean weight than dirty weight for particular coupons.
Success Rating:
Results successful using TACT (time, agitation, concentration, and temperature, as well as rinsing and drying) and/or other cleaning chemistries examined.Conclusion:
In the application of unheated immersion with an air drying overnight period, Fatty Acid Methyl Ester 93% + Methyl Lactate 7% was not an effective cleaner for removing production oil and grease. In future testing, a drying step may be needed to gather more accurate mearurements.
