Tuesday, September 21, 2010

Ultrasonic Transducers: Stacked vs. Crystal Bonded

In the ultrasonic cleaner industry units are typically manufactured in two ways - with stacked transducers or with crystal bonded or flat transducers. The transducers emit high frequency sound waves into a liquid solution that creates cavitation in the ultrasonic bath to clean for numerous applications. Generally speaking flat transducers have lower power parameters than stacked transducers, and as such stacked transducers with their higher power parameters are usually used in heavy duty industrial cleaning applications. However, as will see a little later in this article the term “power” does not translate into “cavitation intensity” and the term “more power” does not reflect on cleaning efficiency. Some manufacturers and importers have created a misnomer in regards to the power of stacked vs. flat transducers in ultrasonic cleaners and as such the intent of this article is to clarify the terminology and context in which it’s used.

Many cleaning applications such as those in health care, jewelry, laboratories, weapons, and recreational industries require the use of standard lab type ultrasonic cleaning units. These units generally make use of strategically placed flat ultrasonic transducers as to provide enough cavitation intensity to effectively clean without damaging parts, or the integrity of the stainless steel tank and the transducer itself. There has been some misleading marketing hype stating that stacked transducers have far more power than crystal bonded transducers - this is true, but only in context.

Stacked transducers are indeed capable of much more power input and output amplitude levels than flat transducers as they are constructed to accommodate the stresses from high energy output amplitudes. The easiest way to think of transducers is like sound system speakers. The speakers in your car are manufactured to provide ample listening pleasure because there are many small speakers strategically placed throughout - this is similar to crystal bonded or flat transducers. In contrast the speakers at a U2 concert are massive and constructed to handle the high power input signals and intense output amplitudes to provide more than ample listening pleasure for stadiums that hold tens of thousands of fans - this would be the stacked transducer.

The context in which these transducers (speakers) are designed, constructed, and used is imperative to understanding so called power levels. It would be accurate to say that stacked transducers are capable of more power; however, it would be inaccurate to say an ultrasonic cleaner is more powerful simply due to the fact that it has stacked transducers bonded to the bottom of the tank. A stacked transducer requires more power simply because of the mass that has to be moved due to its construction, but what about the transducer’s output amplitude and the cavitation intensity within the ultrasonic bath? A well designed stacked transducer bonded to the bottom of a standard off-the-shelf lab type ultrasonic cleaner will have such intense output levels that it would cause problems for the integrity of the ultrasonic tank. Think about our speakers again - put concert style speakers in your car matched with the output amplitude or sound levels they are designed for and you’d destroy your car - not to mention your hearing. The same concept applies to ultrasonic cleaners - we want to match a well designed and constructed transducer with a durable environment that will take the punishment of high level output amplitudes.

Lab type, table top ultrasonic cleaners are limited in regards to their durable environment both in construction and size. Therefore, we want to match a well designed transducer to fit within these confines in order to be capable of generating intense cavitation (cleaning power) throughout the range of varying load conditions that the cleaning application will encounter. We need to also consider that there is a cavitation threshold limit for ultrasonic cleaners - that is a point at which regardless of how much power is introduced into the system the cavitation intensity will not increase. We also need to recognize the fact that if we try to impart too much power and subsequent output amplitude into a lab type ultrasonic it will cause the radiating surface (the tank) to erode and create a hole. So, this misnomer that suggests that an ultrasonic cleaner with a stacked transducer is more powerful than an ultrasonic unit with a crystal bonded transducer has not been put in context thus far, but let’s delve a little deeper.

The design and materials of any transducer are extremely important in regards to efficiency and life - they must be designed to accommodate the frequencies, output amplitude, and stresses incurred during operation, and should be designed for maximum life. Poorly designed and poorly constructed transducers regardless if they are stacked or flat will have a short life expectancy as they will become fatigued during the stresses of operation and deteriorate thus becoming inefficient and/or cracking. A well designed and well constructed transducer will provide long life expectancy and will efficiently accommodate the rigors of the fluctuating power demands and stresses it realizes in maintaining cavitation intensity as load conditions change inside an ultrasonic bath.

The term “power” in itself can be misleading - generally speaking “power” is the amount of energy required to move the mechanical components such as the transducer and radiating surface/tank in order to create cavitation. Cavitation intensity is what determines the effectiveness of an ultrasonic cleaner, and cavitation intensity must be controlled to accommodate varying load demands within the parameters of the ultrasonic cleaner specifications to be effective. Simply stated, a stacked transducer by its design alone is going to require more power than a crystal bonded transducer so as to move its mass in order to create any level of cavitation intensity. Increasing the load conditions in the ultrasonic bath is going to cause the transducer to have an increase in power level to sustain adequate cavitation intensity. Too much power is not going to have any effect on cavitation intensity, and will cause the ultrasonic unit to become cannibalistic.

It seems that most of the hype over stacked transducers versus crystal bonded transducers has come from availability of inexpensive, less than quality constructed transducers that are available from outsourced vendors today. The claim is both true and false depending upon the context in which the expression “stacked transducers are more powerful” is used. Sonix 4 uses stacked transducers on our industrial duty systems, and they are indeed powerful - if we were to use them on our lab type units the units the integrity of the tank would be compromised over a very short period of time.

So now what? Disregard the general claim that just because the ultrasonic unit has a stacked transducer it’s more powerful. Trust a manufacturer that knows how to design, match, and manufacture ultrasonic transducers for the environment that they are intended. It is even better if the manufacturer backs their transducers with a 10 Year Warranty as is the case with Sonix 4.

Monday, July 26, 2010

Some Processing Specifics

It is important to consider certain aspects of the cleaning process in order to maximize cleaning efficiency and decrease the possibility of staff personnel exposure to pathogenic microorganisms.

Cleaning Solutions:

Cleaning solutions specifically formulated for ultrasonic cleaning and known to be compatible with the instruments to be cleaned are recommended to increase cleaning effectiveness and to protect the instruments from possible damage. Neutral or alkaline detergents are the most commonly used formulation that hospitals, surgical facilities, dental practices, and veterinarians use with ultrasonic cleaners.

Temperature:

Temperature of the liquid will affect both cavitation quality and the chemical cleaning action. Usually both can be improved by increasing operating temperature, however the cleaning solutions have a temperature point where they begin to break down, thus decreasing the cavitation and cleaning results. The optimum temperatures will vary according to the solutions physical properties, but as a rule of thumb most aqueous solutions cavitate best within the temperature range of 140-190 degrees Fahrenheit (60-88 degrees C), or as a general rule 2/3 the boiling point of the liquid. Beyond this optimum range cavitation will gradually decrease and at the boiling point cavitation will cease altogether. To avoid damage to the surgical instrument the temperature of the solution should not exceed the instrument's temperature parameters as recommended by the instrument manufacturer.

Since bacteria can proliferate in the ultrasonic cleaner's detergent solution its strongly recommended that the cleaning bath be changed often and regularly, and that a fresh volume of water be used for rinsing each new batch of instruments to minimize personnel exposure to potentially pathogenic microorganisms, to protect the instruments, and to prolong the life of the ultrasonic cleaner.

Accessories:

The benefits of ultrasonic cleaners can be maximized by using specially designed instrument baskets, trays, or cassettes. Accessories are crucial as they maximize exposure of the instruments to the direction of the ultrasonic waves, protect the instruments from damage abrading against each other during cleaning, and preventing the instruments from coming into contact with the bottom of the ultrasonic cleaner's tank which will cause damage to the unit. Accessories also provide protection for personnel minimizing the amount of instrument handling and potential injury.

Cleaning Cylce Time:

In addition to the type of cleaning solution used and the bath temperature, the cycle time needed to clean instruments will depend upon factors such as the load size - the number and arrangement of contaminated instruments, the degree of instrument contamination (e.g., lightly-soiled, heavily-soiled), as well as the frequency and power output efficiency of the ultrasonic cleaner.



In addition to increasing the productivity of reprocessing staff and minimizing the staff's exposure to contaminated instruments, ultrasonic cleaners have been shown to be substantially more effective and efficient than other methods for instrument cleaning whose results are often incomplete and unpredictable as they are unable to reach contamination in the hidden recesses that many of today's complicated surgical instruments possess.

Sonix IV Ultrasonic Cleaners have set the benchmark for cleaning and instrument reprocessing technology. For more than 38 years Sonix IV has been developing and manufacturing highly innovative ultrasonic cleaning products that address the need for versatility, flexibility, and efficiency in today’s environments.

Friday, July 9, 2010

How effective is ultrasonic cleaning?

Understanding that cavitation is the mechanism of cleaning in ultrasonic technology the effectiveness of ultrasonic cleaning can be controlled by several factors including how the acoustic signal is transferred into the cleaning tank, how efficiently that sound energy is converted to cavitation energy, and how that energy is transferred to the parts.

With today's increasingly complex surgical instruments, and the different materials used in their construction consideration of frequency and frequency modulation should be considered as a precaution to prevent part damage due to the varying components ability to absorb energy. The cavitation energy release and density from the collapsing bubbles formed in the cleaning solution is relative to the frequency and/or frequency sweep range of the ultrasonic transducers. Generally speaking low frequency ultrasonics will have superior performance for large particle removal while high frequency ultrasonics will yield better results for sub-micron particle removal, or precision cleaning.

When using ultrasonic cleaners to clean surgical instruments it's imperative that the equipment have sweep frequency circuitry that improves the performance of the cleaner and reduces the potential for damage to delicate parts.

Ultrasonic cleaning standardizes the cleaning process for removing dried serum, whole blood, microorganisms and other fine debris from inaccessible surfaces on contaminated instruments. Some reports suggest that ultrasonic cleaning, preceded by soaking in an enzymatic solution results in an even greater reduction in patient debris, and have demonstrated that as few as three minutes of ultrasonic exposure was sufficient to remove 99% of blood on contaminated instruments.

Reprocessing instructions for most surgical instruments recommend ultrasonic cleaning as an integral step in the preparation for sterilization. Some materials, such as quartz, silicon, and carbon steel may erode or become etched after prolonged exposure to ultrasonic cavitation, but can can be minimized, if not eliminated by reducing the ultrasonic cleaner's power and cleaning time. Review of each instrument's instruction manual from the manufacturer should determine whether ultrasonic cleaning is recommended.

Ultrasonic cleaning is usually a multi-step process that begins with a pre-soak to remove gross debris - this step is performed immediately after the instrument's use to prevent patient contamination from drying. Followed by immersion into the ultrasonic bath - this step is particularly important for removing fine debris that may not be removed using any other method of cleaning. The final steps are rinsing to remove detergent residue and drying. Some processes may involve the addition of a milk bath, or lubricating step to lubricate instruments to prevent corrosion prior to sterilization.

Most standard ultrasonic cleaners will feature a timer to adjust the cleaning time, and covers that reduce exposure of personnel to potentially harmful contaminants and aerosols during cleaning. They may also be equipped with temperature controls to increase the temperature of the detergent solution, and power intensity controls that permit adjustment of their power output (Watts), as well as instrument trays, holders and baskets.

Factors that can enhance or limit cleaning effectiveness:

Several factors can enhance or limit the cleaning effectiveness of an ultrasonic cleaner. None is as significant as the physical properties of the cleaning solution and that solutions ability to propagate the ultrasonic energy. The point at which cavitation begins is called the cavitation threshold and is reached when the energy applied is sufficient to drop the pressure within the liquid below its vapor pressure during rarefaction. The properties of the cleaning solution, which include its temperature, viscosity, density, vapor pressure, and surface tension cause the threshold value to vary such that changes in any one of these properties is likely to affect cleaning effectiveness.

Monday, June 28, 2010

Ultrasonic Cleaning Technology for Infection Control: What is it?

Ultrasonic cleaning is an effective technology routinely used in health care facilities worldwide to clean surgical and dental instruments prior to sterilization. The primary physical phenomenon of ultrasonic cleaning is cavitation, - cavitation is a by-product of transmitting high frequency sound waves into a liquid medium and is one of natures most efficient amplifiers of energy density known to man.

Alternating phases of rarefaction and compression during sound wave transmission into a liquid will produce and subsequently collapse millions of microscopic vacuum cavities each second. The collapse or implosion of these cavities cause high powered micro-jets of liquid to be propelled throughout the bath removing even the most tenacious particles upon impact. The rate at which these cavities form and implode, as well as the intensity of the implosions are proportional to the frequency that is being transmitted. During the rarefaction or minimal pressure phase of sound wave transmission the liquid is stretched beyond its tensile strength whereby millions of microscopic vacuum cavities form. These cavities form and build to tremendous temperatures and pressures - then upon the compression phase of the sound transmission the cavities are compressed beyond their elastic threshold until they collapse or implode. The implosions radiate shock waves that drive the liquid violently creating micro-jets of effluent to blast throughout the bath.

Each collapse is accompanied by the generation of temperatures of several thousand degrees centigrade and pressures greater than hundreds of atmospheres.

The key factor in cleaning effectiveness of an ultrasonic system is cavitation. The greater the cavitation intensity of the liquid - the better the cleaning results will be.

Wednesday, May 19, 2010

Sonix 4 Cleaning Solutions

Sonix 4 Corp. offers a line of cleaning solutions that are specially formulated to provide optimum cavitational cleaning properties. The specifics of each product available are listed below for your convinience:

Sonix 4 Cleaning Solutions

Product:
983 Ultra-Concentrate General Purpose Solution
Description:
Premium quality, non ionic, ultra-concentrate solution formulated with optimum cavitational properties, for removing numerous contaminants from instruments,
burs, and various other items.
Dilution:
40:1 with water, or 4 ounces/gallon
pH:
12
Properties:
Clear liquid
Instructions:
Dilute with water directly in ultrasonic tank, 4 ounce/gallon - clean for 10 minutes.

Product:
683 Temporary Cement Remover
Description:
For the removal of temporary cements.
Dilution:
Ready to use formula - no dilution required.
pH:
13.5
Properties:
Yellow liquid
Instructions:
Do not dilute - use indirect method using glass beaker filled with solution and
immerse beaker in ultrasonic bath - clean for 5 to 10 minutes.

Product:
483 Tarter and Stain Remover
Description:
Formulated especially for the removal of calculus, tartar, tobacco and food
stains from dentures, partials, crowns, and bridges.
Dilution:
Ready to use formula - no dilution required
pH:
.08
Properties:
Clear liquid
Instructions:
Do not dilute - use indirect method using glass beaker filled with solution and
immerse beaker in ultrasonic bath - clean for 5 to 10 minutes.

Product:
CNB General Purpose Powder
Description:
An easy to use powder form to remove debris from instruments and
appliances.
Dilution:
1 tablespoon/gallon of water
pH:
12
Properties:
Blue powder
Instructions:
Use 1 tablespoon per gallon of water directly in ultrasonic tank -- clean for 10
minutes.

Product:
CNB Tartar & Stain Remover
Description:
An easy to use powder formula for removal of tartar and stains from dentures,
partials, crowns, and bridges.
Dilution:
1 tablespoon/gallon of water
pH:
.08
Properties:
White powder
Instructions:
Using the indirect method - add 1/2 teaspoon of powder with water in a 600 ml
beaker - immerse beaker into ultrasonic bath -- clean for 5 to 10 minutes.

Friday, April 2, 2010

Stainless Steel and Microbial Erosion

Stainless Steel and Microbial Erosion

Sonix 4 Corporation uses stainless steel in manufacturing the industry’s leading ultrasonic cleaning systems. As such it is important for our customers to have some level of education in regards to the makeup of stainless steel which will ultimately say something about the integrity of the metal when in the working environment.
Over time some users may have noticed the creation of holes within the stainless steel tank. These holes, or pits, can cause serious problems once moisture is allowed to leak into the electronic components of the ultrasonic unit. Once a pit is created, and the unit is run for any period of time, we can expect the hole to exponentially increase in size. This is due to the powerful cavitations that occur when a Sonix 4 ultrasonic unit is in operation. So the question that becomes important is, “How can I prevent pits from being created in the first place?”
The answer comes from the knowledge of the chemical makeup of stainless steel, and the dangers that the working environment can introduce into the ultrasonic tank. Stainless steel differs from carbon steel in the fact that it contains more Chromium. Carbon steel will corrode when it comes in contact with the air and moisture due to the active film of iron oxide (Fe(OH)3), or rust, on the surface. Stainless steel with Chromium is resistant to, but not free of this reaction. There is an active film of Chromium oxide (Cr(OH)3) on the surface of stainless steel, and this active film causes concern when in the working environment. In the instruction manual that accompanies the Sonix 4 product there is a list of solutions known to be harmful to the stainless steel tank due to their low pH, or acidic content. The easiest way to think about the reaction that happens to the surface of the stainless steel is with the net ionic equation of any acid base reaction (H+ + OH-  H20). From this equation we can see that the addition of any acid onto the basic surface (due to active film of chromium oxide) of stainless steel will indeed react. The product of the reaction can be visually seen over a period of time in the form of holes, or pits, in the tank.
There is yet another way that acid can be introduced into the tank other than direct addition of acidic solution. They way to think about this is cavities in your teeth. We spend lots of money and time cleaning our teeth to keep them free of bacteria because bacteria produce acids which will react with tooth enamel (Ca5(PO4)3(OH)). This is the basis for the Sonix 4 recommendation that regular cleaning maintenance is necessary to prolong the life of the ultrasonic tank. If the unit is used to sterilize, but is not cleaned after use then there are microscopic bacteria hard at work producing acid solution that will react with the stainless steel creating microbial erosion of the tank. Over time this microscopic process becomes more and more visible as the holes get larger. Furthermore, as stated earlier, once the smallest amount of erosion has occurred the ultrasonic cavitations will be cannibalistic in that they will aid in the rapid erosion of the ultrasonic tank.
So, in summary, “How can I prevent pits from being created in my ultrasonic tank?” Prevention primarily comes from the regular cleaning maintenance of the ultrasonic tank after use. The list of solutions not to be used in Sonix 4 ultrasonic units (Instruction Manual) should also be consulted.

Monday, January 4, 2010

Sonix IV

Press Release For Immediate Release

Sonix IV: A Season for Giving

Sonix IV Donates a Portion of Profits to Charity

Charleston, SC - December, 2009 - Sonix IV is a company with purpose manufacturing world class ultrasonic cleaning systems, and working to save lives worldwide by donating a portion of profits and manpower to local and worldwide organizations with the same philosophy: to contribute to the purpose and journey of love, life and equality throughout the world.

Sonix IV supports international organizations such as One, Compassion International, and World Vision with local support to Lowcountry Orphan Relief which Tom Ray, Sonix IV President, manages public relations for.

Gift Sonix IV will donate a portion of it's profits this holiday season, and every other season of the year, to each of the aforementioned charities pursuant to our philosophy of love, life and equality. We at Sonix IV are very thankful to have your support that enables us to help make a difference. Happy Holidays, and we hope that you would continue to join us on our journey pursuant to love, life, and equality this new year.
Visit www.sonixiv.com to find out more.




About Sonix IV

Established in 1972, Sonix IV (http://www.sonixiv.com) (http://www.twitter.com/SonixIV) with headquarters in Charleston, South Carolina is a leading manufacturer of ultrasonic cleaning equipment for industry and professionals world-wide. Ultrasonic cleaning technology provides fast, precision cleaning of parts and assemblies commonly found in manufacturing facilities such as automotive, electronics, semi-conductor, and medical devices -professional services such as dental, medical, veterinary, and optical offices - as well as tattoo establishments, jewelry store and repair shops, dive centers and other sporting segments, government, and weapons cleaning for military, police, and enthusiasts.
Sonix IV
Tom Ray
President

Sonix IV
Tyler Ray
National Accounts Manager
(843) 554-0242
tyler.ray@sonixiv.com