Generally, there are two main types of stains attached to the surface of plastic parts, one is fine particles such as dust, and the other is oily stains such as glycerin and silicone oil. Usually, it is a mixed stain formed by mixing the two and adheres to the surface of the plastic part. Due to the existence of these stains, it will have adverse effects on the subsequent processing, coating, painting, coating, assembly, and other links of plastic parts, and even product quality problems of finished products. Using the physical cleaning effect of ultrasonic waves, coupled with the chemical effect of cleaning agents, and through reasonable ultrasonic frequency and power density, the oil, dust, paraffin and other stains attached to the inner and outer surfaces of various plastic parts can be thoroughly cleaned.
There are so many frequencies of ultrasonics used for cleaning. What frequency is more suitable for cleaning plastics? The frequency of ultrasonic cleaning can be roughly divided into three frequency bands: low frequency (20-50KHz), high frequency (50-200KHz), and mega frequency (above 200KHz). The lower the frequency of the ultrasonic wave, the higher the power density, the more significant the ultrasonic "cavitation" effect, and the better the cleaning effect. The roughness of the workpiece or the high adhesion strength between the dirt and the workpiece surface is suitable for low-frequency ultrasonic waves, and the workpieces that are vulnerable to scratches such as electronic components, optical lens glass, polished metal parts, etc. are more suitable for high frequencies, while the megasonic frequency is generally used for cleaning. Chips, silicon wafer machine films, etc. According to the characteristics of plastic parts and the attached dirt components, it can be determined that the frequency suitable for cleaning plastic parts is low. At present, the commonly used cleaning frequencies in the low-frequency band in the market are 28KHz, 40KHz, and other frequencies. 28KHz is generally used to clean some heavy dirt workpieces, and its noise is relatively large. If it is not difficult for other frequencies to meet the cleaning requirements, it is generally not preferred to use. An ultrasonic frequency of 28KHz is used for cleaning. 40KHz is the most used ultrasonic frequency for cleaning in the market. There are two main reasons: one is that the frequency of 40KHz can meet the vast majority of cleaning requirements; the other is that the technology is mature and the demand is wide. Consumers can also purchase the equipment they need at a relatively affordable price.
What frequency is good for ultrasonic cleaning of plastics? It can be seen from the above that the frequency of 40KHz can be used for ultrasonic cleaning of plastic parts, which is economical and can meet the cleaning requirements. In addition, in addition to the influence of ultrasonic frequency on the cleaning effect of plastic parts, the temperature of the liquid in the ultrasonic cleaning machine tank is also a crucial point. The appropriate temperature is conducive to the best effect of the cleaning agent, which can promote the emulsification and dispersion of stains, reduce the viscosity of oily dirt reduces the adhesion of oil film, which can effectively improve the cleaning effect. In addition, properly increasing the temperature of the cleaning liquid in the tank of the ultrasonic cleaning machine can also increase the ultrasonic cavitation capacity and shorten the cleaning time.
