When choosing the right ultrasonic cleaning machine for your job, you should think carefully. For example, which features are important to you? When you master these 8 points below, you can choose an ultrasonic cleaning machine to do the work you need to do at a great price.
8 tips for choosing an ultrasonic cleaning machine.
1.ultrasonic cleaning tank size
Ultrasonic cleaning tank size, in other words, to clean the parts or handle the number of samples how large?
Measure the size of the parts to be cleaned (or to deal with the number of items or items)
Select the equipment with a tank that can accommodate them
Also, note the size of the part or cleaning basket.
You also need to know the working depth of the cleaning fluid as it relates to the size of the parts to be cleaned. Working depth is the distance from the surface of the basket to the liquid in the internal bottom surface of the filled ultrasonic cleaning tank. Because the parts to be cleaned must be completely immersed in the liquid. On the other hand, sample preparation may require a smaller depth because the entire container does not need to be immersed in the solution.
Product specifications for benchtop ultrasonic cleaners may not contain this information. If not, please feel free to ask the manufacturer or supplier. On the other hand, manufacturers of large industrial tanks often report tank depths and working depths.
2. How do you use ultrasonic cleaning equipment?
Ultrasonic cleaning machines can do much more than clean parts such as gears, carburetors, PCB boards and surgical instruments. They are widely used in laboratories to degas solvents, disperse nanoparticles and emulsify, dissolve, disperse and prepare laboratory samples.
If you are cleaning parts, the following things need to be considered before you begin the selection process.
First, the type of contaminant to be removed. As you can imagine, there is a big difference between removing coolant from machined parts, varnish deposits from carburetors, ink from printing, and blood and tissue residue from surgical instruments.
Second, the composition of the product to be cleaned. Different parameters apply to the cleaning of aircraft engine components and glass capillaries. Need compatible cleaning fluid and ultrasonic cleaning frequency.
Three, how to use the parts after cleaning?
Fourth, how do you define “clean”?
V. Do you want to clean batches or individual parts?
Six, component size and weight
Once you have determined the task to be accomplished, these points will help you narrow down your choices and thus make a choice of ultrasonic cleaning machine purchase requirements. Then it is time to contact the ultrasonic cleaning machine manufacturers for specific advice.
3. The choice of ultrasonic frequency
In conventional cleaning, the frequency selection is generally in the range of 20 ~ 40 kHz and 68 ~ 120 kHz two segments. In the low frequency band formed in the cavitation bubble radius is larger, collapse when the strength is also large, but not uniform enough, suitable for removing 3 ~ 5 um of dirt particles. The higher the frequency, the higher the cavitation threshold, that is, the greater the sound intensity required for cavitation, and the finer and more uniform the formation of cavitation bubbles.
Low frequency band is suitable for cleaning the surface of large workpieces and dirt and cleaning surface bonding strength of high occasions, but not easy to penetrate deep holes and surface shape of complex components. While the high frequency band cavitation intensity “mild”, noise is small, the chemical bubble is relatively dense and uniform, you can drill parts with complex shapes, slits, deep holes, blind holes in the parts for cleaning.
In practice, ultrasonic cleaning frequency reference data.
Powder metallurgy parts such as magnetic cores, magnetic rings, with grinding magnetic powder class, select the frequency of 20 ~ 25 kHz;
Rough machining of metal parts, such as automotive wheels, cylinder components and other large parts, select the frequency of 25 ~ 28 kHz;
For watch parts and precision stampings, a frequency of 40 kHz is suitable;
For optical glass and low-grade liquid devices, a frequency of 68 to 120 kHz is suitable.
For semiconductor silicon wafers, liquid crystal glass substrate cleaning electrode lead width of 8 pm, or line spacing of 8 pm, the requirement to remove 1 ~ 3 pm of dirt particles, you need to choose 0.8 ~ 1.0 MHz of flowing megahertz ultrasonic cleaning.
Currently, in the ultrasonic cleaning process, less use of a single frequency, often two or more frequencies. Rough cleaning with a lower ultrasonic frequency, fine cleaning with a higher ultrasonic frequency, and all with a sweep function. Cleaning process is also used in more methods, there are compound cleaning, alternating between respect cleaning or with double frequency transducer frequency hopping cleaning, which is conducive to improving the quality of cleaning and production efficiency.
4. Ultrasonic power selection
Cleaning tank ultrasonic power to determine the sound field in the size of the sound intensity, the size of the sound intensity and directly affect the effect of cavitation, therefore, to choose the appropriate ultrasonic power.
If water is used as the main cleaning medium, the ultrasonic cleaning power reference data.
Cleaning optical glass liquid crystal products, ultrasonic power of 10 ~ 20W / L;
Cleaning precision instrument components, ultrasonic power of 20 ~ 25W / L;
Cleaning metal internal pressure parts, ultrasonic power is 25~30W/L;
For cleaning powder metallurgy parts and fine casting parts, the ultrasonic power is 30~35W/L;
For injection molded devices, due to the complexity of the components, itself is a sound-absorbing body, ultrasonic power in 35W / L or more.
Ultrasonic cleaning effect is not necessarily completely proportional to the power, cleaning time. For a workpiece adhering to dirt, if the cleaning machine power is not enough, then spend more time, the washing effect is also very limited, the power is appropriate, dirt immediately removed. Ultrasonic power is too large, although the cleaning effect is obvious, but may make the precision workpiece surface etching points, the oscillator work surface will also produce cavitation corrosion, which should be avoided. Too much sound intensity will cause too many cavitation bubbles. Increase scattering attenuation, the formation of acoustic barriers, so that sound waves do not easily spread throughout the liquid space, away from the sound source, can not form a balanced cleaning, how to choose the ultrasonic power, need to be based on the shape of the workpiece material, the nature of the cleaning fluid, process and other comprehensive considerations.
5. Whether the need for heating function
Ultrasonic cavitation will generate heat, the use of heated solutions, many cleaning tasks will be faster and more effective. For example, the cleaning solution suitable cleaning temperature of 40-60 ℃ especially in the cold if the cleaning solution temperature is low cavitation effect is poor, cleaning effect is also poor. Therefore, there are some cleaning machine in the cleaning cylinder around the outside of the heating wire for temperature control, when the temperature rises after the cavitation is easy to occur, so the cleaning effect is better. When the temperature continues to rise later, the gas pressure inside the cavitation bubble increases, causing the impact sound pressure decreases, reflecting the multiplicative effect of these two factors. However, it is important to note that heating the solution does not enhance certain cleaning operations. For example, the removal of blood from surgical instruments. So do you need this heating function?
6. Do you need degassing function
Degassing mainly uses the “directional diffusion” of ultrasound, and once cavitation is generated, there is still air inside, so in some molten liquid degassing and purification applications it is preferable not to generate cavitation. Liquid air exhausted, reduce the resistance of the bubbles generated by ultrasonic cavitation reaction, to enhance the cleaning efficiency of the ultrasonic cleaning machine. There is another role is that ultrasonic cleaning machine work for a long time will produce a kind of ultrasonic fatigue, reduce the cleaning effect and efficiency, oxygen removal degassing function can also eliminate this ultrasonic fatigue.
7. Whether the need to sweep the frequency function
Sweeping frequency is in the cleaning process of ultrasonic frequency in a reasonable range of reciprocal sweeping, its role is to improve the ultrasonic cleaning tank ultrasonic field structure.
Ultrasonic cleaning machine work in a fixed frequency has greater limitations, due to certain parameters, such as water temperature, cleaning volume, etc. changes, easy to produce the resonant frequency drift, resulting in changes in sound power, affecting the cleaning effect.
8. Whether the need for pulse function
If you want to clean the pollutants particularly tenacious products, please specify the ultrasonic cleaning machine equipped with pulse mode. On some models, pulse mode can increase the ultrasonic power up to 20% to remove stubborn contaminants.
If you want to degas the solvent, choose a model with a degas mode or a pulse mode. Ultrasonic cleaners without these modes will also degas the solvent, but the speed will be slower.
Differentiate the quality of ultrasonic cleaning machine good or bad tips
1, check its affiliation with the brand influence in the industry
One of the tips to identify the quality of laboratory ultrasonic cleaning machine is to determine the influence of its brand, although this belongs to a high degree of precision instruments, but there are differences in the brand. If it is a little-known brand, I’m afraid it is difficult to provide accurate after-sales service in place, the only operation of the regular big brands can help customers solve substantive problems.
2, from the details of the parts to judge the workmanship of the cleaning machine
Efficient ultrasonic cleaning machine not only to maintain the operating rate at a high level, but also for the parts of the workmanship is relatively fine, which can be accurately concluded through careful observation. Some people do not care about this part, when the ultrasonic cleaning machine appears in front of the eyes, measuring a few eyes will turn their attention elsewhere, this action is not desirable.
3, from having the function to assess the practicality
Ultrasonic cleaning machine corresponds to the different categories, set the function also exists a big difference, and even for the cleaning object also varies, which is to have the function from it to assess the practicality of the high and low. In other words, whether the cleaner can meet their own real needs, than the cleaner with the number of functions more worthy of attention.
4, ultrasonic performance test
Method one: glass cleaning method
Select single-sided frosted glass sheet, moderate specifications, and then select the same batch number of products before cleaning, diagonally on the glass sheet with a 2B pencil drawing a fork as a cleaning object marker, the glass surface vertically placed in the perspective of the loaded items cleaning basket and in Xin a total of 5 pieces, after the prescribed cleaning procedures cleaning, observe the results to the glass sheet on the pencil scratches completely disappeared, judged to be the cleaning effect for qualified, and note down Each time the experimental results.
Method two: aluminum foil (tin foil test method)
Aluminum foil paper can choose 10 nanometers, 20 nanometers or 30 nanometers of different thicknesses, all produced by the same batch of good, the aluminum foil paper are placed parallel and vertical in the bottom of the ultrasonic cleaning machine tank, within 100 mm from the bottom of the cleaning tank, and do not touch the bottom. The use of windows can not uniformly perforate the principle of aluminum foil paper, after setting the program ultrasonic cleaning, to aluminum foil paper uniform perforation for cleaning effect qualified, if there is a blank bit greater than 6.45 square meters, then that the equipment is not qualified.