Questioning Particle Generation Due to Cavitation Erosion as a Source of Contamination

Ultrasonic cleaning is widely used for removing particles from surfaces.  It is generally agreed that the high energy of implosions of cavitation bubbles break the bonds holding particles to the surface being cleaned and that liquid motion (streaming) carries the particles away once they have been dislodged.  However, it is also well known that ultrasonic cavitation …

Ultrasonic “Double Boiler”

Maximum ultrasonic performance requires the most efficient transfer of ultrasonic vibrations from the ultrasonic transducers to the liquid in the process tank.  This is generally accomplished by applying ultrasonic transducers directly to the exterior surfaces of a tank containing the process liquid.  Transducer attachment techniques favor attachment to metals like stainless steel.  What if the chemistry to be used …

Cleaning Sintered or Porous Parts

Most surfaces that we encounter in industrial cleaning are relatively smooth and contiguous.  We have talked earlier about the difficulties of cleaning blind holes, threads, capillary spaces and other challenging configurations. The one surface we haven’t yet explored is that of a material that is itself porous.  Sintered materials including metal, ceramic, glass, plastic and …

Ultrasonic Machining – A New Use for Ultrasonics?

Over the years, there have been several anecdotal references to otherwise unexplained changes in the properties of surfaces exposed to ultrasonic energy in a liquid.  In some cases, it would make sense that the change was due to increased cleanliness.  In others, however, the benefit of cleanliness alone would seem questionable.  One incident in particular …

Sound Physics – Nodes and Antinodes – Part I

I’ve made reference in the blog before to the fact that some surfaces are good candidates for ultrasonic cleaning while others are either difficult or impossible to clean.  In general, surfaces that are hard (metal, glass) are easily cleaned using ultrasonics while softer surfaces (rubber, soft plastic) resist ultrasonic cleaning.  The reason has to do …

Chemical Concentration – Economic and Process Considerations (cont.)

My previous blog addressed the chemical cost of using too much (or perhaps too little) “soap” in a cleaning process based on chemical cost.  Today we look at process issues. You might be saying, “What the heck?  So I use too much chemical.  Soap is cheap and I look at it as “insurance”.”  Well, that “insurance” …

Chemical Concentration – Economic and Process Considerations

I have talked before on the blog about the subject of chemical concentration and its relationship to cleaning.  A couple of recent incidents prompt me to re-address the subject of chemical concentration but from a little different angle. It’s a “no-brainer” that cleaning chemicals are expensive and, with the possible exception of heat and labor, …