Many ultrasonic cleaning systems are purchased with specialized baskets or holding fixtures which support parts in specific positions during the ultrasonic cleaning process.  Reasons for this include to maximize the number of parts which can be cleaned in a single batch, to prevent  parts from coming into contact with neighboring parts, to prevent damage to parts being cleaned, or to release in trapped air pockets which may prevent effective ultrasonic cleaning at these locations.

Parts which are cleaned in an ultrasonic cleaner can be of any conceivable shape and design.  In some cases, parts can be most effectively cleaned in a vertical orientation.  Examples of such parts include sputtering targets, plastic injection mold plates, and other thin part designs.  In these cases, fixturing is added to the basket design to support multiple parts positioned vertically with a small amount of space in between neighboring parts, similar to dishes in a dishwasher.  If parts such as these were cleaned in a horizontal position, the lowermost part would receive the most intense ultrasonic cleaning activity since it is closer to the ultrasonic radiating surface.  This first part would absorb some of the ultrasonic energy being emitted, and would reduce the amount of available cleaning action on parts directly above this first part, a principle known as "Ultrasonic Shadowing."  This is the primary reason why parts are normally cleaned in a single layer when using ultrasonic cleaning system.

Some part designs include blind holes or other detailed areas which have a tendency to entrap air when submerged in a liquid.  Ultrasonic cleaning can not take place where entrapped air is present.  in many cases, and trapped error can be released from the product when positioned in a specific orientation which allows these cavities to fill with processing fluids.  However, one must also consider that these locations must also drain adequately to prevent detergents used in the ultrasonic cleaning bath from transferring into the rinse tanks, thereby increasing the requirement of rinse water to maintain it at acceptable levels.

In other cases, the customer requires that parts be cleaned without coming into contact with any other components during the cleaning process.  In these cases, compartmentalized baskets, or those baskets with dividers of some sort are normally provided.

Other customers may require that parts be cleaned without coming into contact with any metallic surface which may produce damage to their parts.  In these cases, baskets are specifically designed with softened contact points to prevent such damage without impeding the ultrasonic activity at the part surface. 

Some may ask why plastic baskets are not commonly used in these instances.  The reason is that most plastics reduce available ultrasonic cleaning action significantly by Ultrasonic Shadowing.  The ultrasonic energy is emitted from the bottom of the tank, strikes the plastic which absorbs most of the energy, and leaves only a fraction of the power available to clean parts inside of the basket.  In some cases, ultrasonic activity is completely shadowed, and parts are not adequately cleaned. 

Zenith Manufacturing & Chemical Corporation can design fixtures or specialized baskets for any cleaning application or part design while simultaneously ensuring that the fixture maximizes the ultrasonic cleaning action produced in the system.

Part Positioning:

• Is Used to Release Entrapped Air from Parts.
• Is Used to Prevent Part Damage
• Used to Prevent Neighboring Parts from Coming into Contact
• Can Maximize the Number of Parts Cleaned per Batch
• Fixtures Should be Designed to Minimize Ultrasonic Shadowing

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Zenith Mfg. & Chemical Corp.
85 Oak St.
Norwood, NJ  07648-0412
800-432-SONIC (7664)
FAX: 201-768-6999
sales@zenith-ultrasonics.com