Trial Number 4

The top four products based on past testing results were again diluted to 5% using DI water in 400 ml beakers. All four were heated to 130 F on a hot plate. Peweighed aluminum coupons were coated with the StarChem StarSol 775 AL metalworking fluid (64742-52-5, 102-71-6, 141-43-5, 4719-04-4) using a handheld swab. The contaminant was allowed to dry for about 10 minutes. Once dry, the coupons were weighed a second time to determine the amount of oil applied.

Three coupons were immersed into each solution and cleaned for 5 minutes using stir-bar agitation. Rinsing was performed for 15 seconds using tap water heated to 120 F and followed by 30 seconds of air blow off with dry compressed air at room temperature. Final weights were recorded, and efficiencies were calculated for each coupon cleaned.

Three of the products were effective at removing the metalworking fluid from the aluminum coupons within 5 minutes of immersion cleaning. These 3 removed more than 92% of the metalworking fluid. The other product removed 81%. The table lists the amount of soil added, the amount remaining and the efficiency for each coupon cleaned.

The three lab selected products were found to have good removal of all five soils using heated immersion cleaning. The client supplied product was moderately successful on all five soils. The addition of mechanical energy, either ultrasonics or spray washing, may be enough to improve the products efficiency on the more challenging soils.