Ultrasonic Cleaning Chemicals 101: A Look at Today’s Options

Suppose you were faced with a cleaning challenge in which an object was heavily soiled, but could not be cleaned with conventional, forceful methods.  No scrub brushes, no high-pressure water jets and no aggressive chemicals could be used, all of which might damage the object or be unable to reach every spot needing to be cleaned. How would you as a manufacturer clean such objects? Especially those that are sensitive, small or enclosed? One modern technology offers just the solution:  ultrasonic cleaning. 

Ultrasonic cleaning employs high-frequency, high-intensity sound waves transmitted into a fluid bath to create cavitation within the fluid. Cavitation involves microscopic bubbles being repeatedly formed and collapsed within a fluid, creating a “rolling boil” of sorts so small that the human eye cannot see it occurring. 

While microscopic, these tiny bubbles can generate extreme internal pressures measured at thousands of pounds per square inch, and can collapse so violently that they create internal temperatures of several thousand degrees Fahrenheit. When ultrasonic cleaning encounters a soiled object and is tuned to an appropriate frequency, the sheer energy produced by its cavitation can attack soils at the molecular level without damaging the base object. 

Manufacturers can put ultrasonic technology to use in achieving hands-free, relatively quick, thorough cleaning of their small or sensitive parts. Ultrasonic cleaning can even clean portions of an object that cannot be directly seen, so long as the wash fluid can make it into the area and contact the soils.

The Chemistry of Ultrasonic Cleaning

In setting up an ultrasonic cleaning system, most of the upfront discussion is on the physics of the cleaning process. The mechanical aspects – namely ultrasonic frequency, energy density, cleaning bath volume and part handling – get all the initial attention. Once the system is installed however, the chemistry portion of the equation becomes paramount. Selection and management of the cleaning agents to be added into the ultrasonic cleaning system provide users with highly customizable flexibility toward achieving their cleaning goals. (It’s worth noting that in some cases, incorrect chemistry selection can in fact almost completely inhibit cleaning as well.) 

When evaluating ultrasonic cleaning chemicals, key factors to review include:

• Chemical formulation and base ingredients
• Recommended concentration/dilution
• Viscosity 
• Specific gravity/density
• Effective life  
• Rinsability
• Dry-ability  
• pH
• Recommended operating temperature
• Compatibility with soil types and object materials
• Cleaning cycle time 
• Expected entrained gas content in the cleaning fluid
• Geometry of the cleaning vessel and object to be cleaned

As an example case, take a precisely manufactured metallic object that needs to be cleaned of soluble organic materials. Running the part through an ambient temperature, water-only ultrasonic cleaning bath for two minutes results in an approximate 60 percent removal of soils. The cavitation frequency alone is able to dislodge most (though not all) of the soils from the object, and some soils suspended in the water basin re-adhere to the object upon removal. Trying the cleaning process again with the addition of a 4 percent potassium hydroxide detergent and heating the wash fluid to 145 degrees fahrenheit, achieves a complete removal of soils from the object, as well as early completion before the two-minute timer elapsed.  

In the above example, the added detergent improves cavitation performance in a few ways:

• The potassium hydroxide solution (along with its other surfactant ingredients) lowers the surface tension of the wash solution, driving soils to more easily separate from the object being cleaned.
• The elevated temperature, higher wash viscosity and aggressive alkaline pH act to emulsify the organic soils into their molecular building blocks, dispersing them off of the object and into suspension.
• With the soils greatly broken down by the above factors, the cavitation process now can much more easily perform its cleaning job to break up, separate and “scrub” the object free of soils.
• The increased density of the wash solution drives up the minimum cavitation bubble size, making the ultrasonic cycle more effective with a higher proportion of forceful micro-bubble implosions.

Modern Ultrasonic Cleaning Chemicals

Today’s ultrasonic wash chemicals vastly improve the performance of cleaning processes compared to last-gen offerings. Chemistry, technology and wash science improvements have come so far, that JAYCO routinely offers specially formulated chemical programs to fit your exact applications. We understand the integral relationship between your ultrasonic cleaning equipment and its wash chemistry, as well as how both of these factors need to precisely align with the exact parts and soil loads you’re dealing with. Below are a few examples of where modern chemical technologies get us today:

• Chemical ingredients can be selected for compatibility with your exotic alloy, engineered thermoplastic or other advanced part materials, assuring that cleaning is achieved damage-free.  

• Chemistries can be fine-tuned over time to arrive at the ideal concentration, temperature and ultrasonic frequency settings for your applications.  

• Chemical programs can be custom-matched to your industry and application, directly supporting your overall QA objectives. In the medical and food process sectors for example, chemistries can be specified with FDA-certified and compatible ingredients. 

• JAYCO solves for the entire cleaning process, not just the wash cycle. Placing chemical solutions that altogether speed up cleaning as well as sheening, rinsing and drying steps is our norm.  

• Solving for chemical supply challenges of the future, JAYCO today designs formulations that keep raw material availability, stock capacity and other supply chain factors squarely in mind. Our product development cycle targets availability and reliability just as critically as the chemistry design itself.     

• In addition to the above, sustainable environmental and human protection are paramount in our formulating process, from choosing biodegradable, non-hazardous agents to maximizing active chemical life (thus reducing water and wastewater impacts).

JAYCO Chemical Solutions is North America’s single-source provider of engineered cleaning solutions. From process analysis and application engineering to delivery and support, JAYCO improves operations for precision metal, medical, optical, UHV, space/aerospace and general manufacturing customers. For more information on JAYCO Chemical Solutions, our products and our markets, please call us at (814) 593-0022, or email us at info@jaycochem.com.