Ultrasonic cleaning machines are widely used in industries such as electronics, healthcare, automotive, and optics. They achieve the cleaning of the surface of objects by generating a cavitation effect in the liquid through ultrasonic vibrations. One of the core components of an ultrasonic cleaning machine is the water tray (water tank), which is a container for holding the cleaning solution and is usually made of metal, stainless steel, or plastic materials. The function of the water tray is to contain the cleaning solution and provide a stable environment for the conduction of ultrasonic waves and the generation of bubbles. However, during the operation, the water tray must withstand the tests of high-frequency ultrasonic vibrations, chemical corrosion in the cleaning solution, temperature changes, and other factors. Therefore, the sealing of the water tray and the durability of the materials have become important factors determining the performance of the cleaning machine. Among these factors, the adhesive used in the water tray (that is, the sealant) plays a crucial role, directly affecting the stability, service life, and safety of the equipment.
The adhesive used for the water tray is not just for the purpose of sealing. It also needs to meet a series of functional requirements, including corrosion resistance, high-temperature resistance, the ability to withstand ultrasonic vibrations, and good adhesion, among others. Now, let's discuss in detail the basic requirements of the water tray adhesive from several aspects.
In an ultrasonic cleaning machine, the cleaning solution is usually a liquid containing various chemical substances, such as detergents, acidic and alkaline solutions, etc. These cleaning solutions may have a corrosive effect on the rubber material of the water tray. Therefore, the rubber used for the water tray must possess excellent corrosion resistance, effectively resisting the chemical components in the cleaning solution, preventing the rubber material from aging or degrading. This ensures that the sealing performance remains stable over an extended period of time.
During the ultrasonic cleaning process, the temperature of the cleaning solution often rises, especially when heating is required to improve the cleaning efficiency. The water pan adhesive must be able to withstand the changes in the temperature of the cleaning solution and have a relatively high temperature resistance (generally between 80°C and 150°C) to avoid softening, deformation, or performance degradation caused by high temperatures.
The ultrasonic cleaner drives the cavitation effect through high-frequency vibrations. Such vibrations may exert a certain impact force on the water pan adhesive. Therefore, the water pan adhesive needs to have a certain degree of vibration resistance and impact resistance to prevent phenomena such as adhesive layer peeling, cracking, or aging caused by the vibrations, thus maintaining a good sealing effect.
Adhesion and Flexibility
The water pan adhesive needs to adhere well to the materials of the water pan, such as stainless steel, plastic, etc., to ensure the sealing effect. In order to meet the adhesion requirements of different material surfaces, the adhesive material should have strong adhesive force. Additionally, during the operation of the ultrasonic cleaner, it may experience certain thermal expansion and contraction. Therefore, the adhesive material must also possess good flexibility to cope with these changes without losing its sealing ability.
According to the working conditions of ultrasonic cleaners and the performance requirements for adhesive materials, the commonly used adhesives for water pans mainly include silicone rubber, polyurethane adhesive, epoxy resin adhesive, and fluororubber, etc. Different types of adhesives have different characteristics and applicable scenarios. The following will introduce their advantages and disadvantages respectively.
Silicone is a very common type of sealant, which has excellent high-temperature resistance, weather resistance, and corrosion resistance. Silicone can maintain stable performance within a temperature range from -60°C to 250°C, making it highly suitable for use in high-temperature environments. It has good flexibility and can withstand a certain degree of thermal expansion. Therefore, it is often used in the water trays of ultrasonic cleaners that need to withstand high temperatures and vibrations.
Pros：
- Excellent high-temperature resistance.
- Good chemical stability and corrosion resistance.
- Outstanding flexibility and adhesive force.
Cons：
- Silicone rubber has poor resistance to mechanical abrasion and may get damaged in a high-impact environment.
- Silicone rubber has poor tolerance to certain solvents, so it is necessary to make the selection according to the actual situation.
Polyurethane adhesive has strong abrasion resistance, corrosion resistance, and toughness, and it is widely used in many industrial applications. It is suitable for sealing applications that require high strength and resistance to vibration. Polyurethane adhesive has a certain degree of heat resistance, but generally, its high-temperature tolerance is not as good as that of silicone rubber.
Pros：
- Excellent abrasion resistance and impact resistance
- Good elasticity and flexibility, suitable for high-vibration environments
Cons：
- Relatively poor high-temperature resistance (usually within 120℃)
- Poor tolerance to certain chemical substances and may not be suitable for use with some cleaning solutions
Epoxy resin adhesive is renowned for its strong adhesive power and corrosion resistance, making it suitable for use in some special cleaning solutions or chemical environments. Once it cures, the surface has a high hardness, and it can provide a stable sealing effect in high-intensity environments. However, epoxy resin adhesive has relatively poor flexibility and may not be suitable for applications that need to withstand significant thermal expansion or impact forces.
Pros：
- Strong adhesive force and corrosion resistance
- High hardness after curing, suitable for stable sealing
Cons：
- Lacking in flexibility, it is prone to cracking
- Relatively poor resistance to high temperatures
Fluororubber performs excellently in terms of high temperature resistance and corrosion resistance, and it is especially suitable for environments where it needs to withstand strong acids and alkalis. Its temperature resistance can reach above 200℃, making it suitable for use in high-temperature and harsh chemical environments.
Pros：
- Excellent corrosion resistance, especially in strong acid and strong alkali environments
- Outstanding high-temperature resistance
Cons：
- Higher cost
- Poor adhesiveness, requiring special surface treatment
The adhesive used for the water pan of an ultrasonic cleaner is an important component that ensures the stable operation of the equipment. Selecting the appropriate adhesive material is crucial for enhancing the sealing performance of the equipment, extending its service life, and ensuring the cleaning effect. According to different working environments and the characteristics of the cleaning solution, users can choose suitable types of adhesives, such as silicone rubber, polyurethane adhesive, epoxy resin adhesive, or fluororubber, to achieve the optimal usage effect. With the development of ultrasonic cleaning technology, the requirements for adhesive materials will also continue to increase. In the future, there may be more applications of new adhesive materials, further promoting the advancement of ultrasonic cleaner technology.
