For a step-by-step guide to qualifying 3M replacements, see our article (click title) “7 Tips for Qualifying 3M Novec Replacement Vapor Degreaser Solvents”.
End-users that want to maintain control of their supply of high precision solvents for their critical cleaning needs should start the process of identifying and qualifying replacements as soon as possible. The alternative would be operating at the whims of global demand on a very restricted supply.
On December 20, 2022, 3M announced their plans to phase-out their Novec PFAS-based product lines by the end of 2025: “3M today announced it plans to exit per- and polyfluoroalkyl substance (PFAS) manufacturing and work to discontinue use of PFAS in its product portfolio by the end of 2025. This portfolio decision is based on careful consideration and a thorough evaluation of the external landscape, including multiple factors such as accelerating regulatory trends focused on reducing or eliminating the presence of PFAS in the environment and changing stakeholder expectations.”
Let’s start with what happens when some solvents are out-of-date. Solvents containing alcohol are hydroscopic, so absorb moisture from the air. What starts as 0.2% moisture could drift up to an unacceptable purity level, as it is exposed to ambient air. If sealed, this will happen extremely slowly. That depends on the packaging and sealing method, which we have full control of. Once a container is opened, we no longer have control of it, so it is impossible to give a credible number. If you close it after every use, and have a humidity controlled environment, the same shelf life is probably still applicable. If you leave the container open and you are in the tropics, it will probably pass that unacceptable threshold a lot more quickly. Whether or not 0.5%, 1%, or 10% moisture contamination is acceptable for your operation depends on what you are doing with it. Some aerospace customers absolutely demand their isopropyl alcohol (IPA) is 99.8% pure, so they manage their inventory very carefully. Other customers dilute 99.8% IPA with DI water to make their own 70% IPA for cleaning stencils. There really necessarily a real-world expiration date for that level of criticality.
If the chemistry is a good solvency match to the soil, less sonic agitation will be needed. This allows you to run your cleaning process more quickly, at lower temperature, and lower amplitude, decreasing the likelihood of damaging sensitive components. The following are characteristics to look for when reviewing options: Solvency – Ability of the cleaner to breakdown and dissolve the soil. For a quick evaluation of solvency, place a drop of cleaner directly on the soiled part, let it sit for a few minutes, and they blot it dry. From this simple test, you can generally tell if the chemistry is a good match to the soil. If the cleaner just sits on the surface of the soil, and doesn’t wet and start to break down the soil, move on to the next cleaner. Surface tension – This impacts how well a solvent can get into tight crevices, like under low stand-off components. Density – Density can have a minor impact on how quickly the sonic waves travel through the liquid, and the amount of cavitation. A higher density material requires more energy to move, so could deplete the energy, thus the cleaning power, by the time it reach the part.
Yes, PWR-4 high performance solvent cleaners are nonflammable, powerful cleaners like nPB, safer than nPB, and are also economically priced.