Ultrasonic Cleaning

Question:

I am manufacturing pipe fittings and using graphite as a dry lubricant while the steel is being formed. I am trying to remove this graphite after the forming process so that the machinist, down the line in the factory, doesn't have to breathe it. Would a vibration table work? Would aqueous cleaning be required? If so, what kind of cleaning solution would you use? Thanks. B.F.

Answer:

Although you may remove some of it, I believe a good percentage of the graphite would still adhere to the steel too strongly for it to be removed by a vibratory table. To remove most or all of the graphite, I believe you could aqueous clean the parts, but that would also likely require some type of mechanical force. Ultrasonics would likely be the most effective method to remove the residual graphite.

A relatively mild aqueous cleaner would be used (surfactants plus a low percentage of builders for pH buffering) in this process. It would also be important to continuously filter the bath to remove the graphite contaminant, otherwise the tank will quickly become contaminated and redeposit the graphite back onto the parts. You could have the entire system done by a turnkey manufacturer that specializes in ultrasonic cleaning systems. The cleaner would likely be followed by a rinse, although if a pretreatment supplier was involved early in the development process, you could likely identify a good no-rinse cleaner. It would have a mild “soap” to aid in graphite removal and rust inhibitors to minimize or eliminate rusting of the pipe fittings. This would eliminate the need for subsequent rinse and rust inhibitor tanks saving floorspace and capital. I would recommend looking on PF Online under Suppliers, choose the category Cleaning & Pretreatment, then Cleaning and Pretreatment Equipment and finally Transducers, Ultrasonic. This will provide you with a list of knowledgeable manufacturers of ultra-sonic cleaning equipment.