Detergents

A customer needed to clean an assembly of a printed circuit board which had been sweat soldered to an aluminum plate/heatsink/carrier. The company needed a cleaner that would not attack the Alodine coated aluminum backside or the gold pockets or solder reflowed surface of the circuit board.

Unfortunately, the current cleaner was slightly base ph 9+ and the water slightly alkaline as well coming in at a ph of 8.0. This, along with other factors, caused staining, darkening and spotty discoloration of the 6061 Alodine coated (chemical conversion coating) aluminum parts.

When cleaning aluminum, it is assumed that the aluminum has been exposed to air and has formed the typical aluminum oxide layer prior to cleaning. If recently machined, aluminum must be cleaned and it cannot be allowed to air passivate. Therefore, a cleaner that contains appropriate metasilicate inhibitors such as Solujet, Detojet, Alcojet or Tergajet must be used.

Q. Which Alconox cleaners are low foaming for use in mechanical washers?

A. Alconox, Inc makes both powder and liquid; acid and alkaline; and phosphate containing and phosphate-free low foaming cleaners. You need a low foaming cleaner for use in mechanical washers that rely on spraying to clean surfaces.

Q. We manufacture metal parts in house and overmold (LIM) with silicone. We often have adhesion problems between the silicone and metal. We believe the problem is with our current cleaning process. I would like you to recommend a new cleaner that we can test.
A. If having silicone and metal adhesion issues in medical device cleaning, use the hottest practical temperature you can to remove silicone residues. I recommend you clean with very hot 2% Alconox (20 g/L of 2.5 oz/gal) detergent.

Q. How long will the enzyme in a 1% solution of Tergazyme remain active?
A. A 1% Tergazyme solution is designed to give good reliable cleaning performance for 8 hours at 120 deg F. This is designed to correspond to an 8 hour work shift.