Ultrasonic nozzle, also known as ultrasonic atomization nozzle, is an ultrasonic atomization device based on the principle of horn transducer. The liquid is atomized by high frequency ultrasonic oscillation after amplification and amplification, and the liquid mist is sent to the sprayed object or specific space by a certain amount of carrier gas. Without exceeding the limit, the volume of liquid atomization is determined only by the delivery volume of the liquid and the working frequency of the spray head. A variety of coatings, chemicals, lubricants, particle suspensions, etc. can be atomized. However, the viscosity, miscibility and solid content of liquid should be considered. For the best atomization effect, the liquid viscosity should be less than 30 CPS, and the solid content should be less than 30%. Because the atomization process is affected by the movement effect of liquid film, high viscosity will inevitably cause low atomization quantity, which will bring difficulties to the application. Due to the high cohesion of high polymer molecules, atomization of liquids containing high polymer molecules is problematic even in dilute conditions. Most of the time, the mixture of solid particles can be atomized. Because the solid particles will be dispersed in the atomized particles. Even coarse mud can be atomized at low speed to the nozzle.
Compared with the traditional two fluid spraying, ultrasonic spraying has the advantages of high uniformity of coating, high utilization rate of raw materials, high precision of coating thickness control, thinner coating thickness, less splash, no nozzle blockage and low maintenance cost. Compared with vacuum evaporation, CVD and other coating processes, ultrasonic spraying is a more economical film coating process, especially in large area film preparation, the equipment cost of ultrasonic spraying is much lower than that of vacuum coating equipment. Let's briefly introduce these main advantages of ultrasonic spraying.
1. High uniformity of coating
The distribution uniformity of liquid particles after atomization by ultrasonic nozzle is significantly higher than that of two fluid spray nozzle, which is commonly known as air spray gun, so the coating uniformity of ultrasonic nozzle after spraying has been significantly improved. In general, the coating uniformity of ultrasonic spraying can reach more than 95%.
2. High utilization rate of raw materials and less splash
Because ultrasonic spraying is liquid atomization by ultrasonic oscillation, the atomization process of coating does not need any gas, that is, the atomization process does not need any pressure. Only a very low carrier gas pressure is applied to transport the liquid mist after atomization, so the liquid rebound and splash caused by high-pressure air in two fluid spraying are greatly reduced, thus greatly improving the utilization rate of coating. The material utilization rate of ultrasonic spraying is more than 4 times of that of common air spraying, and the highest utilization rate can be more than 90%.