Ultrasonic cleaning technology and selection of cleaning solution

Before purchasing the cleaning system, the following application analysis should be done for the parts to be cleaned: the material composition, structure and quantity of the parts to be cleaned, and the dirt to be removed shall be analyzed and determined. These are the preconditions for determining what kind of cleaning method to be used and for judging whether water-based cleaning solution or solvent is used. The final cleaning process needs to be verified by cleaning experiments. Only in this way can we provide a suitable cleaning system, design a reasonable cleaning process and cleaning solution. Considering the influence of the physical properties of the cleaning solution on ultrasonic cleaning, steam pressure, surface tension, viscosity and density should be the most significant factors. Temperature can affect these factors, so it also affects the efficiency of cavitation. Any cleaning system must use cleaning fluid.

The following three factors should be considered when selecting cleaning fluid:
1. Cleaning efficiency: when selecting the most effective cleaning solvent, we must do experiments. If ultrasound is introduced into the existing cleaning process, the solvent used does not need to be changed;
2. Simple operation: the liquid used should be safe, non-toxic, easy to operate and long service life;
3. Cost: the use cost of the cheapest cleaning solvent is not necessarily the lowest. In use, the cleaning efficiency, safety and the number of workpieces that can be cleaned by a certain amount of solvent must be considered. Of course, the selected cleaning solvent must achieve the cleaning effect and be compatible with the material of the workpiece to be cleaned. Water is the most common cleaning fluid, so the system using water-based solution is easy to operate, low-cost and widely used. However, it is not suitable for water-based solutions for some materials and dirt, so there are many solvents to choose from. Different cleaning fluid, to distinguish the cleaning system water-based system: usually composed of open tank, the workpiece immersed in it. The complex system is composed of several tanks and equipped with circulating filtration system, flushing tank, drying tank and other accessories.

Solvent system: mostly for ultrasonic vapor phase grease cleaning machine, often equipped with waste liquid continuous recovery device. The ultrasonic vapor phase oil removal process is completed by an integrated multi tank system composed of solvent evaporation tank and ultrasonic immersion tank. Oil, grease, wax and other solvent soluble dirt are removed by hot solvent vapor and ultrasonic agitation. After a series of cleaning procedures, the workpiece is heated, clean and dry.
Cleaning parts treatment

Another consideration of ultrasonic cleaning is the loading and unloading of cleaning parts or the design of tooling for placing cleaning parts. When the cleaning parts are in the ultrasonic cleaning tank, neither the cleaning parts nor the cleaning parts basket can 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 groove. Rubber and non rigid plastics can absorb ultrasonic energy, so care should be taken when using these materials in tooling. Special attention should also be paid to the cleaning parts of insulation. The efficiency of the best ultrasonic cleaning system will be greatly reduced even if the tool basket is not designed properly or the workpiece is too heavy. Hooks, shelves and beakers can be used to support the cleaning parts.
Cleaning time: 3-10 minutes, it is better to use timing cleaning.