Q: We use Alconox on the medical device parts we manufacture that need cleaning before shipment. Alconox detergent is working in an excellent way with austenitic stainless steel parts, but is not working that well with martensitic stainless steel. Actually, at the end of the process cleaning martensitic steel, we notice some marks on the material. Any recommendations?
Surface contamination interferes with formation of protective oxide coating on stainless steel thereby leaving it open to corrosion. The stainless steel needs passivation.
Q. White spots appear on our stainless steel parts the day after cleaning with Alconox. Right after we clean them, they are dry and visually clean. So, is this next-day residue from the Alconox detergent? If not, can you tell us why this is happening? A. It is fairly unlikely that visually clean parts have Alconox residues suddenly appearing the next day. In addition to Alconox being free rinsing, any residue that did not get rinsed for whatever reason, would be visible fairly immediately.
Most people in similar situations, even though the parts appear “dry and visually clean,” find that the spots are from water.
Q. We are looking for a low concentration surfactant to improve DI water wetting to polycarbonate and stainless steel during an aerated flushing operation for removal of sub-micron surface particles. Our parts are cleaned before assembly – we need to improve a DI-water flushing operation that is meant to remove sub-micron sized surface particulate from inside an assembled gas path (tube). How can we improve wettability of DI water?
Q. Can we use liquinox to wash the passivated stainless steel parts?
A. Liquinox can be used to clean passivated stainless steel. Liquinox will not degrade the passivation of stainless steel. Martensitic or 400 series stainless steel is best cleaned at reduced temperatures below 100 deg F (below 45 deg C) so that you can rinse with the same temperature water without risk of breaking any emulsions and redepositing oils during rinsing.