The composition and characteristics of ultrasonic cleaning machine

Ultrasonic cleaning machine is mainly composed of ultrasonic cleaning tank and ultrasonic generator. The ultrasonic cleaning tank is made of high-quality stainless steel with good elasticity and corrosion resistance, and an ultrasonic transducer vibrator is installed at the bottom; the ultrasonic generator generates high frequency and high voltage, which is transmitted to the transducer through the cable connecting line, and the transducer is together with the vibrating plate. A high-frequency resonance is generated, so that the solvent in the cleaning tank is subjected to ultrasonic waves to clean the dirt.

  Characteristics of ultrasonic cleaning:

  1. Good cleaning effect, high cleanliness and consistent cleanliness of all workpieces

  2, the cleaning speed is fast, the production efficiency is improved, no manual contact with the cleaning liquid is required, and the ultrasonic cleaning machine is safe and reliable

3. It can also clean deep holes, slits and hidden parts of workpieces

  4, no damage to the surface of the workpiece, saving solvent, heat, workplace and labor.

The ultrasonic cleaning method exceeds the general conventional cleaning method, especially the surface of the workpiece is more complex, such as some mechanical parts with uneven surfaces and blind holes, and some products that are particularly small and have high requirements on cleanliness, such as watches and precision machinery. Parts, electronic components, circuit board components, etc., using ultrasonic cleaning can achieve ideal results.

   Ultrasonic cleaning process and selection of cleaning solution

  Before purchasing a cleaning system, the following application analysis should be done on the cleaned parts:

  1. Clarify the material composition, structure and quantity of the parts to be washed;

  2. Analyze and identify the dirt to be removed;

  3. Determine the cleaning method to be used, determine whether to use aqueous cleaning solution or solvent, and finally need to do cleaning experiments.

  Only in this way can we provide a suitable cleaning system, a rationally designed cleaning process and a cleaning solution.

  Choice of Chemicals

   Considering the influence of the physical properties of the cleaning solution on ultrasonic cleaning, the vapor pressure, surface tension, viscosity and density should be the most significant influencing factors. Temperature can affect these factors, so it also affects the efficiency of cavitation.

  A cleaning fluid must be used in any cleaning system. Aqueous systems usually consist of an open tank in which the workpiece is submerged. Complex systems will consist of multiple tanks, equipped with circulating filter systems, shower tanks, drying tanks and other accessories.

   For systems that use solvents, most of them are ultrasonic vapor-phase degreasing cleaning machines, which are often equipped with continuous waste liquid recovery devices. The ultrasonic vapor phase oil removal process is completed by an integrated multi-tank system consisting of a solvent evaporation tank and an ultrasonic dip tank. Oil, grease, wax and other solvent-soluble soils are removed under the combined action of hot solvent vapor and ultrasonic agitation. After a series of cleaning processes, the unloaded workpiece is hot, clean and dry.

  When choosing a cleaning fluid, the following three factors should be considered:

  1. Cleaning efficiency: When choosing the most effective cleaning solvent, be sure to do experiments. If ultrasound is introduced into the existing cleaning process, the solvent used generally does not need to be changed;

  2. Simple operation: the liquid used should be safe and non-toxic, easy to operate and have a long service life;

  3. Cost: ^ The cost of using cheap cleaning solvents is not necessarily ^ low. In use, factors such as cleaning efficiency, safety, and utilization rate of workpieces that can be cleaned by a certain amount of solvent must be considered. Of course, the cleaning solvent chosen must achieve cleaning results and be compatible with the workpiece material being cleaned. Water is the most common cleaning solution, so the system using water-based solution is easy to operate, low in cost and widely used. However, for some materials and soils that are not suitable for aqueous solutions, there are many solvents available.

   Cleaning parts treatment

  Another consideration for ultrasonic cleaning is the design of the loading and unloading of the cleaning parts or the design of the tooling for placing the cleaning parts. When the cleaning piece is in the ultrasonic cleaning tank, neither the cleaning piece nor the cleaning piece basket shall touch the bottom of the tank. The total cross-sectional area of the cleaning parts should not exceed 70% of the cross-sectional area of the ultrasonic tank. Rubber and non-rigid plastics absorb ultrasonic energy, so caution should be exercised when using these materials in tooling. Insulated cleaning parts should also be given special attention. Improper design of the tooling basket, or the workpiece is too heavy, the efficiency of even the best ultrasonic cleaning system will be greatly reduced. Any material, if the mesh is higher than 50 mesh, will show solid performance for ultrasonic waves, reflecting the ultrasonic waves back. When the mesh is larger than 1/4 inch, the performance of the open material is only exhibited to ultrasonic waves. Hooks, racks and beakers can be used to support cleaning pieces.

technical parameter

   Ultrasonic Frequency:

  When the working frequency is very low (in the range of human hearing), noise will be generated. When the frequency is lower than 20kHz, the working noise not only becomes loud, but may exceed the limit of safe noise stipulated by the Occupational Safety and Health Law or other regulations. In applications that require high power to remove dirt without concern for damage to the workpiece surface, a lower cleaning frequency in the range of 20kHz to 30kHz is usually selected. Cleaning frequencies in this frequency range are often used for cleaning large, heavy parts or high density materials. artifact.

  HF is often used to clean smaller, more delicate parts, or to remove tiny particles. High frequencies are also used in applications where damage to the workpiece surface is not tolerated. The use of high frequency can improve cleaning performance in several ways. As the frequency increases, the number of cavitation bubbles increases linearly, creating more and denser shock waves that can penetrate into smaller gaps. If the power remains the same, the cavitation bubble becomes smaller, and the energy released by it decreases accordingly, which effectively reduces the damage to the workpiece surface. Another advantage of high frequency is that it reduces the viscous boundary layer (Ponoulli effect), allowing ultrasound to 'find' extremely fine particles. Products with common frequencies on the market are 28KHz, 32KHz, and 40kHz.

  Power Density:

  Power density=transmitting power (W)/transmitting area (cm2), usually ≥0.5W/cm2. The higher the power density of the ultrasonic wave, the stronger the cavitation effect, the faster the cleaning speed, and the better the cleaning effect. However, long-term, high-density cleaning is likely to cause "cavitation" corrosion on the surface of the cleaned object.

   Cleaning temperature:

   Generally speaking, the effect of ultrasonic wave is best at 50℃-85℃.