The selection method of ultrasonic cleaning machineDate: 2022-08-23Number: 248
一、Choice of power
The effect of ultrasonic cleaning is not necessarily proportional to (power × cleaning time) , sometimes with a small power, take a long time did not remove dirt. And if the power reaches a certain value, sometimes the dirt is removed quickly. If the selection power is too large, the cavitation intensity will be greatly increased, and the cleaning effect is improved, but at this time, the more precise parts also produce corrosion spots, and the loss is not worth the gain, and the cavitation at the vibrating plate at the bottom of the cleaning cylinder is serious, water spot corrosion is also increased and is generally not a problem when organic solvents such as trichloroethene are used, but it is susceptible to water spot corrosion when water or water-soluble cleaning solutions are used. If the surface of the vibrating plate has been damaged, the cavitation corrosion is more serious under the strong power, so the ultrasonic power should be selected according to the actual use.
二, the choice of frequency
The frequency of ultrasonic cleaning ranges from 28 khz to 120 khz, and the physical cleaning force caused by cavitation in the use of water or water cleaning agents is clearly beneficial to the low frequency, generally using about 28-40 khz. For small clearance, slit, deep hole parts cleaning, with high frequency (generally more than 40kHz) is better, even hundreds of kHz. When cleaning clock parts, use 400kHz. If the use of broadband FM cleaning, better results.
三、The use of cleaning baskets
In the cleaning of small parts, often use nets basket, because the mesh to cause ultrasonic attenuation, to pay special attention to. When the frequency is 28 khz, it is better to use more than 10 mm mesh./n/n4. The selection of the
四、temperature of the cleaning solution
The optimum cleaning temperature of water cleaning solution is 40-60 ° C, especially in cold weather, if the cleaning solution temperature is low cavitation effect is poor, cleaning effect is also poor. Therefore, some of the washing machine in the washing cylinder outside the heating wire heating temperature control, when the temperature rise after cavitation easy to occur, so the cleaning effect is better. When the temperature continues to rise, the gas pressure in the bubble increases, causing the sound pressure to drop, reflecting the multiplicative effect of these two factors.
五、Determination of the amount of cleaning fluid and the position of the cleaning parts
The general cleaning fluid level above the vibrator surface 100mm is preferred. Due to the influence of standing wave field, the amplitude of wave joint is very small, and the amplitude of wave joint is large, which results in uneven cleaning. Therefore, the best place to choose cleaning items should be placed in the amplitude.
六、The selection of ultrasonic cleaning technology and cleaning solution
Before purchasing a cleaning system, perform the following application analysis on the part to be cleaned: identify the material composition, structure and quantity of the part to be washed, analyze and identify the dirt to be removed, these are the prerequisites for deciding what cleaning method to use and for deciding whether to use a water-based cleaning solution or a solvent. The final cleaning process needs to be verified by cleaning experiments. Only in this way, can provide the appropriate cleaning system, the design of a reasonable cleaning process and cleaning fluid. The steam pressure, surface tension, viscosity and density should be the most significant factors considering the influence of physical properties of cleaning solution on ultrasonic cleaning. Temperature can affect these factors, so it also affects the efficiency of cavitation. Any cleaning system must use cleaning fluid.
The followingthree factors should be considered when choosing a cleaning solution:
1. Cleaning efficiency: when choosing the most effective cleaning solvent, be sure to do experiments. Such as the introduction of ultrasound in the existing cleaning process, the use of solvents generally do not have to change;
2. Simple operation: the liquid used should be safe and non-toxic, simple operation and long service life;
3. Cost: the cheapest cleaning solvent is not necessarily the cheapest to use. In use must consider the solvent cleaning efficiency, safety, a certain amount of solvent can be cleaned how many parts of the highest utilization rate and other factors. Of course, the selected cleaning solvent must achieve the cleaning effect, and should be compatible with the cleaning of the workpiece materials. Water is the most common cleaning solution, so the use of water-based solution system operation is simple, low cost, widely used. However, some materials and dirt are not suitable for aqueous solutions, so there are many solvents to choose from.
七, different cleaning fluid, to distinguish the cleaning system
Water-based system: usually consists of an open groove in which the workpiece is immersed. The complex system consists of a number of tanks, and equipped with a circulating filtration system, shower tanks, drying tanks and other accessories.
Solvent system: ultrasonic cleaning machine for removing oil and grease, often equipped with waste liquid continuous recovery device. The process of oil removal by ultrasonic vapor phase is accomplished by an integrated multi-tank system formed by solvent evaporation tank and ultrasonic immersion tank. Oil, grease, wax, and other solvent-soluble dirt are removed by a combination of hot solvent vapor and ultrasonic excitation. After a series of cleaning processes, the workpiece is heated, clean and dry.
八, cleaning parts processing
Another consideration for ultrasonic cleaning is the design of the loading, unloading or tooling for the cleaning part. When the cleaning part is in the ultrasonic cleaning trough, the bottom of the trough shall not be touched by either the cleaning part or the cleaning basket. The total cross-sectional area of the cleaning element shall not exceed 70% of the cross-sectional area of the ultrasonic groove. Rubber and non-rigid plastic will absorb ultrasonic energy, so this material used in tooling should be cautious. Special attention should also be paid to insulating cleaning elements. The efficiency of even the best ultrasonic cleaning system will be greatly reduced if the tool basket is not properly designed or if the workpiece is too heavy. Hooks, shelves, and beakers can be used to support cleaning items.
九, cleaning time, the type of workpiece, the number of clear
Consider the working mode of the machine is fully automatic, semi-automatic, manual.
* machine size, cost.
The parts which clean a lot of dirt should be pre-cleaned by soaking and spraying. After the removal of most of the dirt, and then use ultrasonic cleaning of the remaining dirt, the effect is good. If the cleaning of small items and complex shape of items (parts) , if the use of cleaning nets or make cleaning rotating, while vibration with ultrasonic radiation, can get uniform cleaning.