Ultrasonic Cleaning FAQs

An ultrasonic cleaner is a cleaner that uses ultrasonic sound waves to clean objects. Ultrasonic means having a high frequency. This frequency is too high for the human ear to detect. The ultrasonic sound waves excite the cleaning solution. When excited, the cleaning solution acts upon and removes the impurities such as grease, dust particles, molds, rust, fingerprints, fungus, soot, and bacteria on objects like glass, metals, ceramics, plastics, and rubber. Below are the ultrasonic cleaning frequently asked questions and their corresponding answers.

Frequently Asked Questions about Ultrasonic Cleaning

What is “cavitation”?

The swift formulation and disintegration of thousands of minute bubbles in a liquid is known as ‘cavitation’. It is generated when high and low pressure waves are alternated using ultrasonic sound waves. In low pressure, these bubbles grow from their microscopic size while in high pressure, they get compressed.

What is “degassing”, and why should it be done?

When gases that are already present in the solution are removed before hand, it is known as degassing. Cavitation only occurs once these gases are removed from the cleaning solution and as a result of that, a vacuum is created in the formed bubble. This bubble crumples once hit by a high wave, releasing energy as a result of that. It aids a detergent when it comes to breaking the bonds between parts and their soils are concerned.

How do I get the best ultrasonic cleaning?

There are several things that you need to keep in mind before getting the ultrasonic cleaning. You need to study all the variables in full detail before making a final call. The most significant thing in this regard is picking the right kind of solution. In addition to that, you need to make a good call regarding the temperature and the time as well as the size and the type of ultrasonic cleaner.

Can ultrasonic cleaning damage my parts?

Ultrasonic cleaning is considered to be pretty safe but not without certain cautions. It is true that thousands of implosions per second can create a very strong effect; the cleaning process does not harm the electronic because of the fact that the energy is restricted at the microscopic level. In addition to that, the choice of cleaning solution matters a lot here. Negative effects of a detergent can get enhanced after the ultrasonic process.

Why is a special ultrasonic cleaning solution required for ultrasonic cleaning?

Soil sticks to the small parts and that is why a solution is used in ultrasonic cleaning. This cleaning solution helps in breaking the ties between parts and their soils. Water alone cannot do this and this special ultrasonic solution is required, which gets assistance from the ultrasonic activity. An ultrasonic cleaning solution includes different ingredients that are specially made for the cleaning process.

Which cleaning solution should I use?

A number of detergents, wetting agents and other such components are used in the making of a modern ultrasonic cleaning solution. And there is a variety of formulations available from which you can take your pick depending on the application. Selecting a proper solution is very important for a satisfactory cleaning job and to stop unwanted reactivity with the part being cleaned.

Which cleaning solution shouldn’t I use?

Flammables or solutions that have very low flash points should never be used. Cavitation releases energy which is then turned into heat and kinetic energy. As a result of that, high temperature gradients in the solutions are produced. This can be very hazardous for the part being cleaned. Therefore you need to avoid using acids, bleach and other such products. However, they can be used if you are using an indirect cleaning container like a glass breaker. But when it comes to stainless steel tanks, acids can form hazardous conditions.

When should the ultrasonic solutions be changed?

If you notice a decrease in cleaning action or when the solution is very dirty or depleted, it is the time to change the cleaning solution. However, you must remember that every cleaning session does not require a new batch of solution.

What is the length of cleaning time?

The length of cleaning time depends on several factors such as soil, solution, degree of cleanliness required and temperature. Shortly after the start, you will notice the removal of highly visible solid. The adjustment of cleaning time is not that difficult and the new application duration can be judged if there is an experienced operator. It usually depends on the solution and the parts that you seek to clean.

What is the purpose of the ultrasonic cleaners heater?

The main purposed of the ultrasonic heater is to keep the solution temperature balanced between the cleaning cycles. The heat for cleaning is generated by the huge amount of energy released by cavitation.

How do I know if my ultrasonic cleaner is cavitating properly?

If one or more process variable is not controlled properly, it affects the cleaning process and the output. Factors such as choosing the detergent solution, heat, and time, should be accessed carefully in order to remove the soil. And you can always tests the “glass slide” and the “foil” test in order to check whether you ultrasonic cleaner is working properly or not.

How do I perform the “glass slide” test?

In order to perform the glass slide test, you need to wet the frosted portion of a glass slide using simple tap water. Draw a simple X using a number 2 pencil from one corner to the other on the frosted side. Do not forget to fill the tank to its capacity and submerge the frosted end of the slide into the cleaning solution and turn the ultrasonic on. You will notice that the X will star to be eliminated at that very instant and within ten seconds, it should be all gone.

How do I perform the “foil” test?

Take three tiny pieces of 4” x 8” of an aluminum foil and fold each of it over a rod that will later be used to suspend the foil in the tank. Or you can alternatively take clothes hanger for this purpose. Make sure that the cleaner is filled with an ultrasonic solution and is at normal temperature. Now you need to suspend the first piece of foil in the center of the tank. After that, suspend the other two couple of inches away from each other. Do not forget to fill the tank to its maximum capacity and then turn on the ultrasonic for say ten minutes. Inspect after that by removing the foil. All three pieces should be perforated and furrowed.

What is the optimum cleaning temperature?

Heat is used to fasten up the cleaning process and most of the detergents work best at high temperatures. You can run various tests to check the best temperature which is usually within the 50°C to 65°C range.

Is rinsing required after ultrasonic cleaning cycles?
In order to remove any chemical remainders, rinsing is necessary to avoid any harm. You can use an ultrasonic cleaner to rinse the parts using a clean water bath. Or you can alternatively use distilled or de-ionised water.

How does indirect cleaning work?

It is nothing but the practice of filling an ultrasonic tank with either a cleaning solution or simple water and then adding a solid container into the tank. Solid container is usually a solid tray or a breaker. After that, the container is filled with either the same or different liquid.

It is a simple procedure as the ultrasonic energy is transmitted from the transducers attached to the bottom of the tank. The wavefront transmits through the water in the tank as long as it does not meet a physical object, which can be either the side of the tank, or the air/water interface at the top of the tank. If you pass the solid container mentioned above, it will sonify the liquid as well by passing through it.

It does make sense – but why would anyone would like to do that?

  • This will allow you to keep your main tank clean by putting the entire solid inside that solid tray.
  • You won’t need to clean your tank ever.
  • It will allow you to avoid cross-containment as you can do more than one matches of tiny parts in various solutions.
  • You can even use those liquids that you cannot use in your water tank otherwise.
  • It will save your expenses.
  • It will allow you to judge which is the most effective of the cleaning processes.

It is pretty obvious that indirect cleaning is as vast as ultrasonic itself. And you are missing on so many things if you are not taking advantage of it. Rather you are paying extra money.