Trial #1
To evaluate cleaners using longer times and elevated temperature
Three products from the previous trial were diluted to 20% using DI water in 1000 ml beakers. A fourth solution was used a full strength. All four products were heated to 140 F on a hot plate. One part was immersed half way into the solutions and cleaned for 20 minutes. At the end of cleaning the parts were rinsed with tap water at 120 F for 5 minutes. Parts were allowed to air dry. Observations were made at the 10 and 20 minutes. Contaminant: White powders (SiO2, NHCl, (NH4)2SiF6, or NH4HF2)
Three of the four products were moderately successful after the 20 minute soaking. The DS 108 was not very effective. The following table lists observations made at T = 0, 10 and 20 minutes.
Table 1. Cleaning Observations
| Cleaner
|
T = 0
|
T = 10
|
T = 20
|
| 1
|
Instantly cloudy
|
Very dark and cloudy. Still white powder in holes
|
White and crusty. Holes mostly clean
|
| 2
|
Slowly clouding up
|
Cloudy grey. Flat sides look clean. Round edges white
|
White and flaky. Good hole cleaning
|
| 3
|
Slowly clouding up
|
Cloudy. White still on part
|
White and crusty. Good hole cleaning
|
| 4
|
Slowly clouding up
|
Not very cloudy. White still on part
|
Lots of white still on part. OK hole cleaning
|
The three successful products will be evaluated in the next trial using ultrasonic energy.
No relation