FAQ

Generally speaking, ultrasonic refers to the sound wave with frequency larger than 20 KHz which is beyond the upper limit of human ear. Ultrasonic is characterized by strong  beam  property  and  being easy  to collect  energy. through focusing. Ultrasonic is also an energy form, and  when  the intensity  exceeds a  certain value, it can affect, change and damage the state,character and structure of matters through its interaction with sound bearing medium (commonly called ultrasonic power).

In real life, high pitch sound is created by high frequency, and alternatively, the low and base tone is created by low frequency.

Ultrasound is no different from ‘normal’ (audible) sound in its physical properties, except in that humans cannot hear it. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz. Typical ultrasonic frequencies used for cleaning purpose are from 20 kHz to 80 kHz.

• Formation

Ultrasonic cleaner mainly consists of ultrasonic generator, circuit controller, transducer and cleaning tank.

• Working Principle

Ultrasonic generator output oscillation power signal of ultrasonic frequency which  is  then  through  changed  into mechanical oscillation with high frequency by transducer; next, the oscillation is introduced into cleaning liquid,causing the cleaning liquid to produce ultrasonic cavitation effect which can generate tens of thousands of tiny  bubbles which are formed at the negative pressure region and fast closed in the positive pressure region;the closed bubbles form ten thousands of instant high pressure of small pressures, and  the continuously generated instant high pressure is like a sequence of small ‘explosion’ to impact the clearances on the surface of object, causing various pollutant sticking to the surface of object to flake off so as to realize the purpose of cleaning.

“Degassing” is the initial removal of gases present in the solution. Useful cavitation occurs after gasses have been removed from the cleaning solution, leaving a vacuum in the formed bubble. When the high pressure wave hits the bubble wall, the bubble collapses, it is the energy released by this collapse that will assist a detergent in breaking the bonds between parts and their soils.

There are many considerations important to ultrasonic cleaning. Optimizing these variables will produce the best cleaning. The most important decisions to be made are choosing the proper cleaning solution, cleaning at the right temperature for the correct amount of time, and choosing the right size and type of ultrasonic cleaner.

With certain cautions, ultrasonic cleaning is considered safe for most parts. While the effects of thousands of implosions per second is very powerful, the cleaning process is safe since the energy is localized at the microscopic level. The most important cautionary consideration is the choice of cleaning solution. Potentially adverse effects of the detergent on the material being cleaned will be enhanced by the ultrasonics.

Soils adhere to the parts… if they didn’t, the soil would just fall off the parts! The purpose of the solution is to break the bondbetween parts and their soils. Water alone has no cleaning properties. The primary purpose of the ultrasonic activity (cavitation) is to assist the solution in doing its job. An ultrasonic cleaning solution contains various ingredients designed to optimize the ultrasonic cleaning process. For example, increased cavitation levels result from reduced fluid surface tension. An ultrasonic solution will contain a good wetting agent or surfactant.

Modern ultrasonic cleaning solutions are compounded from a variety of detergents, wetting agents and other reactive components. A large variety of excellent formulations are available, designed for specific applications. Proper selection is crucial for acceptable cleaning activity and to preclude undesirable reactivity with the part being cleaned.

Flammables or solutions with low flash points should never be used. The energy released by cavitation is converted to heat and kinetic energy, generating high temperature gradients in the solution, and can create hazardous conditions with flammable liquids. Acids, bleach and bleach by-products should generally be avoided, but may be used with indirect cleaning in a proper indirect cleaning container, such as a glass beaker, and appropriate care. Acid and bleach will damage stainless steel tanks, and/or create hazardous conditions.

The primary purpose of the unit heater is to maintain a solution temperature between cleaning cycles. The tremendous energy released by cavitation will generate the heat for cleaning.

Heat usually enhances and speeds up the cleaning process, and most detergent solutions are designed to work best at an elevated temperature. The best way to find the optimum temperature, which will give you the fastest, cleanest and safest results, is to run tests. Usually, the best results are within the 50°C to 65°C range.