What Are Ultrasonic Waves and How Do They Clean?

Simply put, ultrasonic sound waves are sound broadcast at a frequency beyond the normal range of human hearing. They are used for a variety of applications across industries, including medical imaging (think sonograms) and detecting flaws in manufacturing. At the higher end of their scale, these sound waves can also be used for cleaning. In most industrial ultrasonic cleaning, the frequencies used range between 20 and 50 KHz.

Cavitating Bubbles – the Literal “Scrubbing Bubbles”

When ultrasonic waves move through a liquid and strike a hard surface, they produce millions of tiny bubbles, known as “cavitating bubbles.” These microscopic bubbles produce momentary jets of intense energy when they collapse, directing that energy against the surface they are collapsing against. Repeated millions of times and with the assistance of detergent present in the surrounding liquid, these bubbles scrub away almost any type of grime from all surfaces of an object, no matter how intricate it may be. Furthermore, unlike with traditional brush and solvent methods, they generally do it without damaging the underlying object.

Watch Out for Resonance!

Although ultrasonic wave cavitation cleans thoroughly, efficiently and gently, it is possible for it to damage delicate components in aerospace parts. Be sure to check the limits on ultrasonic cleaning imposed by the manufacturer of the parts. Most have already set strict time and frequency limits for cleaning their parts with ultrasonic cleaners. Sticking to these limits is essential to avoiding resonance damage. Although it may be tempting to leave a part in longer to get it cleaner, the effect that it can cause may be catastrophic. Be sure to follow all the manufacturer’s recommended procedures when working with ultrasonic equipment.

Some ultrasonic cleaning manufacturers, such as Omegasonics, have built in variable timed ultrasound so that resonance doesn’t have a chance to start up and damage components. Resonance cavitation can be seen on items such as boat propellers, when it creates a pitted surface. This can be avoided by changing frequency modulation. Look for ultrasonic cleaning devices which have this feature.

Use the Right Equipment

Having the right equipment matters. When choosing a machine for your ultrasonic cleaning needs, follow the manufacturer’s recommendations and choose the appropriate device for the quality level you need. Call the ultrasonic cleaning company and tell them about the parameters you need. Any reputable company should be able to understand your request and assist you.

Need help with cleaning aerospace parts? To find out more, contact our experts at Omegasonics at 888-989-5560 or email us at omegasonics@omegasonics.com

What is ROI?

ROI is often expressed in a period of time, such as weeks, months or years. Normally, a payback period of one to three years is considered acceptable and a good investment, as this would leave two additional years of expected useful life for most pieces of equipment. However, depending on the piece of equipment, this period could be longer. Ask the manufacturer for more information.

Calculating Labor Savings

Consider this: how long would it take for what I want done to be done via regular labor? How much would it cost me to pay those workers to do that job? And, most importantly, could they do the job, anyway?

Other savings and benefits are certainly worth looking at, but the dollar amount saved will be bigger in comparison to actual labor savings possible from the use of more productive equipment. Good management will always care more about dollars saved over labor saved.

To calculate the hours saved per day, week, month or year, you’ll need to figure out the hours your employees now spend performing the tasks at hand and separately do the same for the estimated hours that would be spent doing the same tasks with the equipment you plan to purchase.

Keep it simple: calculate the total hours saved each day and multiply the hours saved by the number of days worked per month — the average is 21 — to come up with the total hours saved each month. Then, multiply the number of hours saved each month by 12 — the number of months per year — to get an annual number of hours saved.

The savings in hours or minutes per day is the difference between the hours you are spending now per day doing the work versus the number of hours you would spend doing the work at the production rate of the machine that you plan to purchase.

Once you have an estimate of the value of the labor you’re now using and the cost of the labor you would be using with a new piece of equipment, the difference between the two numbers is the cost savings you can expect.

Other increased or decreased costs you need to calculate into the final figure are machine purchase price, repairs, chemicals and any other costs that would be incurred as a result of the change to the new machine.

Other Savings which Affect ROI

New chemical technology, such as Omegasonics’ line of detergents, could bring up to a 30 to 100 percent reduction in chemical costs, depending on the previous application.

Technology Equals Productivity And Reduced Costs

Technology advances so rapidly that even though a piece of equipment may not have reached the end of its useful life, you may want to go ahead and upgrade to a new model that provides additional benefits and is more productive and cost effective. Choose a good vendor with whom you would like to work for a long time and cultivate that relationship. It will pay off in dividends, such as significant price discounts, when it comes time to upgrade.

Keep in mind that most pieces of ultrasonic equipment will last much longer than three to five years. However, the older the piece of equipment, the higher the expected maintenance cost to keep it running efficiently, so you’ll need to also make that part of your ROI calculations. If you do a good job with your calculations, you’ll likely find that it’s easy to justify the purchase of a piece of equipment like an ultrasonic cleaner, which can save money and labor costs for business now and for years to come.

A Variable Temperature Heater

Heating is a natural part of the process that is used in an ultrasonic cleaner. For some applications you may need to get even warmer than cavitation can go. Adding a heater to your ultrasonic cleaner is an option. Heaters are particularly useful when you are dealing with oils, engine or machine coolants and other similar types of grime.

Think of when you would use hot or warm water in your laundry washing machine and you’ll get the idea. Most heaters do have an upper temperature limit. That is because cavitation can lose effectiveness at temperatures higher than this level.

Variable or Sweeping Frequencies

Cavitation is created by vibrations. Those vibrations are created by a transducer in your ultrasonic cleaner.  There are times when you may wish to change the frequency at which your machine operates or even have it slowly ramp up and down a set range of frequencies.

Sometimes small dead zones can be created within your cleaning solution.  These are places where there is little or no cavitation due to several different factors.  A way to ensure a more uniform clean is by using sweep mode. Sweep mode will vary the frequency up and down slowly around a particular value. This will provide you with a guarantee of more uniform cleaning. Sweep modes can also be useful for electronics that can be damaged by remaining certain frequencies and creating harmonic vibrations within a circuit board.

Solution Degas Mode

Liquids like to have things dissolved into them. Your ultrasonic cleaning solution is no exception.  As you pour the clean solution into your tank, gasses can be dissolved into the solution.  There is nothing you can do about this; it is just a simple fact of chemistry. You can remove these dissolved gasses with a degas mode on your ultrasonic cleaner.

Think about boiling water in a pot. Right before the pot begins a rolling boil you will see tiny bubbles forming along the sides of the pot. This is the water in the pot being degassed. Ultrasonic cleaners can do the same thing with vibrations. Set your solution to degas mode five or ten minutes before starting the clean cycle and you will get rid of all those pesky bubbles in the solution.

Omegasonics has the Ultrasonic Cleaners that fit Your Needs

Now it is time to purchase. Our online catalog has many models and sizes of ultrasonic cleaners and all of their options. Get started with your purchase today!

The Traditional Way of Restoration

Traditionally companies that did this type of work did all the cleaning by hand. This meant having several workers using rags, chemicals, brushes and Q-tips in order to remove as much dirt, dust, mold and smoke damage as they could from recovered items.

This process was very time consuming and often involved harsh cleaners and other chemicals. It was very limited in what it could recover in some cases. Even items that were restored might still have a mold or smoky smell to them.

Enter Ultrasonic Cleaning

The limitations of this process is why Omegasonics provides a better way for these companies to get their jobs done. Ultrasonic cleaners are well suited for contents cleaning. In order to restore items that have been damaged in a disaster, cleaning time and effort must be spent getting all contamination removed.

Smoke odors, mold, water damage and soot can find their ways into the smallest corners and openings in objects. While traditional cleaners are limited in what they can do based on the size of the brushes and where they will fit, ultrasonic cleaners can get anywhere and clean any part of an object no matter how small.

Ultrasonic Cleaning is a Better Way

Chemicals and brushes are limited in the amount of cleaning power they have. Detergents are there to dissolve the bonds between the dirt and the surface it is attached to, while brushes are there to remove the dirt once it has been loosened up. A brush can only carry so much energy; this means repeated passes to get things clean.

Ultrasonic cleaners use cavitation action to get items clean. Cavitation works by using very tiny, high-energy bubbles that crash into the surface of the object and blast dirt and contaminates away. Not only does this get items clean and looking as good as new, it also helps remove the odors that can be associated with fire and mold.

Ultrasonic cleaners also save time. What might take a team of workers an entire day to get through can be done in mere hours using an ultrasonic bath. This speeds up the time it takes to return these items to victims and helps them get back on their feet quicker.

If you run a disaster recovery service, come look at what Omegasonics has to offer.

First, a brief review of ultrasonic cleaning. An ultrasound generator along with special transducers mounted to the bottom of a liquid-filled stainless steal bath, alternately compresses and expands the liquid between 25,000 and 130,000 times a second, depending on the application.

This, in turn, generates bubbles, which collapse at high speed, increasing the temperature of the liquid and producing a high energy liquid stream which collides with the surface of the object being cleaned. Essentially, the object is cleaned with a high energy jet spray at the microscopic level.

The choice of liquid for can have a significant effect on the performance of industrial ultrasonic cleaners. While water is most often the choice for ultrasonic cleaning, plain water can be augmented with detergents, or even replaced with other solvents in certain applications.

The video below shows how “chemistry detectives” can test different combinations of variables and chemistries to find the most effective ultrasonic cleaning recipe.

Adding detergents lowers the surface tension of the liquid which reduces the energy required to form bubbles. This can dramatically increase the cavitation, or process by which the bubbles collapse producing the high temperature liquid streams which clean the surfaces. The increased efficiency in producing this cleansing agitation along with the inherent cleaning properties of the detergent results in increased effectiveness of industrial ultrasonic cleaners.

The choice of cleaning medium (called the “chemistry”) is critical to the effectiveness of ultrasonic cleaning. The substrate – or material to be cleaned – as well as the kind of contaminants to be removed, are key factors to consider in selecting the cleaning chemistry. While water or detergents dissolved in water are the most common chemistry used in industrial ultrasonic cleaners, other solvents might by better suited for particular applications.

If you would like to learn more about ultrasonic cleaners, feel free to contact one of our ultrasonic cleaning experts toll free at (888) 420-4445 or visit our website.