It’s important to understand that not all ultrasonic tanks are made the same.
The biggest factor for the variance in ultrasonic cleaning systems is the application for which the tank is being used. More specifically, what will be the expected workload of the ultrasonic cleaning system. The workload is a critical element when considering ultrasonic cleaning systems because there are clear advantages to two competing technologies that are used to build tanks in the marketplace today. The consideration of workload will effect the price, performance and longevity of the system mainly due to the how the tank is built. Here are the two basic categories based on workload, and their advantages:
Category 1: These applications involve cleaning parts on an occasional, as-needed basis. In these applications, a less expensive ultrasonic cleaning system is a better solution based solely on the lack of a rigorous workload. For example, if you are a automotive repair shop and clean intricate parts when rebuilding cylinder heads or carburetors, you could justify purchasing a cheaper system because it will only be used occasionally. If you own jewelry stores and you clean jewelry for your customers, or if you run a business that cleans window blinds for your customers, you could justify purchasing a cheaper system. Generally, the lack of constant operation is a very justifiable reason to purchase a cheaper ultrasonic system.
The basic factor making these types of ultrasonic systems less expensive is the technology by which the ultrasonic energy is created. All ultrasonic systems utilize ‘transducers’ to generate ultrasonic cleaning energy. These systems utilize inexpensive piezoelectric transducers as the mechanism to create their ultrasonic cleaning energy. Piezoelectric transducers have a major advantage in that they are far cheaper and easier to use when manufacturing an ultrasonic tank. Piezoelectric transducers have enabled ultrasonic cleaning to reach a much greater audience and expanded the applications for the convenient and efficient cleaning of intricate parts.
Category 2: These applications involve systems that clean for the majority of the day, every day as part of a strategic productivity increasing process for the company. For example, if you are plastics business and your injection molds require continual cleaning to ensure the quality of your plastic products, you need a system that will consistently perform at the highest level, day after day. Or if you are a hospital and your instruments need to be cleaned to exact specifications to ultimately ensure the health of your patients, you need a system that will consistently perform at the highest level, day after day. Or if you are a commercial jet manufacturer and your electrical and mechanical components need to be properly cleaned to ensure the safety of the crew and passengers, you need a system that will consistently perform at the highest level, day after day.
Blue Wave systems excel in this application termed “industrial” because our tanks are built with the ideal technology to withstand the demands of an industrial environment for literally decades. We use magnetostrictive transducers as the mechanism to create our ultrasonic cleaning energy. Our transducers are fabricated using a special Permanickel Alloy and are silver-brazed to the ultrasonic tank resulting in a more expensive manufacturing process. However, there simply is not a more reliable, longer-lasting or consistent way to generate ultrasonic energy in the world today. In fact, for over 60 years, not one has ever failed. We take great pride in that. We have thousands of systems in the world operating in the most extreme environments and not one has stopped generating consistent ultrasonic energy. This amazing fact is significant because when our competitors ultrasonic transducers slowly deteriorate and eventually stop creating ultrasonic energy, the only course of action is to 1) Scrap the whole tank and buy a new one or 2) Cut the old transducers out of a tank and weld new ones back in. Both options are expensive and obviously create downtime.
In the “industrial” market, the reason our competitor’s ultrasonic transducers deteriorate over time is simple. Their systems utilize the same inexpensive piezoelectric transducers that are used in cheaper systems designed for occasional use. They can not withstand the demands of an industrial environment and deteriorate because of:
Cavitation Erosion. The erosion of the surface of the steel in an ultrasonic tank is called cavitation erosion. In order for Piezoelectric transducers to generate ultrasonic cleaning energy into the tank, they must be mounted directly to the back side of the ultrasonic tank walls (called the radiating diaphragm) that is too thin to withstand the effects of cavitation erosion. A thin radiating diaphragm is used to compensate for the lack of energy produced by the piezoelectric transducers. They do not have the energy producing mass to radiate, or flex, a thicker steel tank wall to produce ultrasonic pressure waves. For this reason, they are mounted to a thinner gauge diaphragm that will flex. Cavitation erosion is generally not an issue for tanks used occasionally because the erosion develops over time with consistent use. In an industrial setting, consistent use makes cavitation erosion a serious concern because the erosion will lead to premature tank failure. The erosion will work away at the steel until a microscopic hole is created in the tank wall. Often the system will only leak when the force of the ultrasonic pressure waves are assisting the detergent through the hole, which means it may not leak unless the system is turned on. With the system running, detergent leaks into the internal cavity of the Ultrasonic system that houses the piezoelectric transducers and other working electrical components. Thus, a tank failure due to cavitation erosion is a very expensive system failure.
Blue Waves magnetostrictive transducers have more mass and create flex in a much thicker radiating diaphragm. Our systems are designed for constant use and our tanks are guaranteed for an industry leading 20 years. Cavitation erosion is not a concern with Blue Wave ultrasonic cleaning systems
Depolarization. Piezoelectric transducers feature a ceramic (usually lead zirconate) crystal that is sandwiched between two strips of tin. When voltage is applied across the strips it creates a displacement in the crystal, known as the piezoelectric effect. This displacement in the crystal causes a movement or radiation in the diaphragm of the tank. When used constantly in an ‘industrial’ application, and with the exposure to higher temperatures, the crystal will depolarize over time. This causes a substantial reduction in the strain characteristics of the crystal causing it to expand less. As the crystal itself expands less, it cannot displace the diaphragm as much, and the strength of the ultrasonic pressure waves are reduced. Obviously this degradation directly effects the ability of the system to clean adequately.
Blue Wave magnetostrictive consist of individual stacks of nickel laminations, the ends of which are zero-spaced and silver-brazed to a stainless steel diaphragm. Enveloping each nickel stack are insulated coils of wire, each of which is powered at 30 kHz by a Blue Wave solid-state electric generator. This in turn vibrates the nickel stacks and diaphragm to 30 kHz. This rugged design has never failed in service.
Higher temperatures. In nearly all ultrasonic cleaning processes, the aqueous detergent in the tank is heated to assist with the cleaning and reduce cycle times. It is a fact piezoelectric transducers deteriorate more rapidly through the process of depolarization as operating temperatures rise.
With magnetostrictive transducers, temperature is not a limiting factor. Blue Wave develops cleaning strategies for our customers that includes the fastest way to completely clean their parts. In several cases, the contaminates will not release from the surface of the parts unless temperatures rise well beyond 160°F. For example, in some cases the contaminates will come off at 170°F, but they come 4 times as fast at 190°F. It is not uncommon for us to recommend the detergents remain at 180°F or 190°F for effective cleaning. It is less common, but we do have customers who keep their cleaning solution consistently above 220°F. Obviously the ability to operate at higher temperature increases the effectiveness and productivity of the cleaning process. With Blue Wave systems featuring magnetostrictive transducers, your systems can clean parts at extreme temperatures, shift after shift, day after day, year after year.
Structural Integrity. When constructed with the thinner tank walls needed for piezoelectric transducers, there is maximum capacity threshold for an ultrasonic tank before structural integrity becomes a concern. The weight of the solution in the tank will bow or bend the thin tank walls increasing the risk for failure. When a tank reaches a larger size with possible integrity concerns, our competition will recommend “immersible transducers”. These are sealed drop-in units that contain transducers required to create ultrasonic energy. Drop-ins are useful when retro-fitting large tanks that a customer may already have (we make them too), but they are not ideal in new tanks because they are generally more cumbersome to operate. Why retro-fit a brand new system?
There is no size limit to Blue Wave tanks. We’ve constructed some of the biggest custom tanks in the world today. In every case, our indestructible magnetostrictive transducers are silver brazed directly to the tank walls to provide maximum ultrasonic power throughout these large scale applications. In fact, it is the exact same construction used to create Blue Wave tanks of all sizes.
The most important decision companies must face when purchasing an ultrasonic cleaning system is to determine whether the intended workload is “occasional” or if it is “industrial”.
If you are certain your workload defines your application as industrial, Blue Wave is the ideal ultrasonic cleaning system for your company. If you are not sure, contact us. We welcome the opportunity to explain every last detail and all of the options available. In fact, we wouldn’t waste your time or ours if we thought our systems and your workload were not a good match. Our goal is to educate our potential customers and let them make an informed decision before they regret spending large amounts of money on a system that is not equipped to handle the job.
For more information concerning ultrasonics in general, visit our Ultrasonic Cleaning 101 page.