With the continuous development and popularization of 3D printing technology, more and more industries begin to use 3D printed parts to manufacture prototypes, functional components and even final products. However, after 3D printing, impurities such as supporting materials, resin or powder often remain on the surface of printed parts, which affects their appearance quality and usability. Therefore, cleaning has become an indispensable part of 3D printing post-processing. Among many cleaning methods, ultrasonic cleaning has gradually become one of the preferred methods for 3D printing post-processing because of its advantages of high efficiency, thoroughness and environmental protection.

First, the basic principle of ultrasonic cleaning

Ultrasonic cleaning is a kind of cleaning technology that uses the "cavitation effect" generated when ultrasonic waves propagate in liquid to remove dirt on the surface of objects. When ultrasonic waves act on the cleaning liquid, countless tiny bubbles will be formed in the liquid, which will rapidly expand and burst, releasing powerful impact force, thus removing tiny particles and pollutants attached to the surface of the object. This cleaning method is especially suitable for 3D printed parts with complex shapes, holes or difficult to clean by hand.
　　Second, the challenge of cleaning 3D printed parts

In the process of 3D printing, especially the parts printed by SLA (light curing) or DLP (digital light processing) technology, photosensitive resin is usually used as the material. After curing, uncured resin often remains on the surface of such materials, which not only affects the accuracy and surface smoothness of finished products, but also may be harmful to human body. In addition, the supporting materials used in FDM (fused deposition modeling) process also need to be completely removed, otherwise the final performance of the parts will be affected.

Third, the application of ultrasonic cleaning in 3D printing.

It is very important to choose a suitable cleaning solution when cleaning 3D printed parts. For photo-cured prints, isopropyl alcohol (IPA) or other special resin cleaning solution is usually used as the cleaning medium. Put the printed parts into the ultrasonic cleaning machine with cleaning solution. After starting the equipment, ultrasonic waves will quickly penetrate into every corner of the parts, effectively removing resin residues, supporting structures and tiny particles.

Compared with traditional manual cleaning methods, ultrasonic cleaning has the following advantages:

1. High efficiency and thoroughness: it can complete the comprehensive cleaning of complex structural parts in a short time;

2. Reduce damage: manual wiping is not needed to avoid surface scratches caused by friction;

3. Save time and manpower: automate the cleaning process to improve production efficiency;
　　4. Environmental protection and safety: reasonable selection of cleaning solution and equipped with sealing cover can reduce volatilization and environmental pollution.

Four, the use of ultrasonic cleaning matters needing attention
　　Although the ultrasonic cleaning effect is remarkable, the following points should be paid attention to in actual operation:

-Avoid too long cleaning time to avoid excessive softening or deformation of materials;

-Select appropriate cleaning solution according to different materials to avoid corrosion or dissolution of printed parts;

-Before cleaning, large residues or supporting structures should be removed as much as possible to reduce the cleaning burden;
　　-Clean the cleaning tank in time after use to keep the equipment clean.

V. Conclusion

Generally speaking, ultrasonic cleaning provides an efficient, safe and environmentally friendly solution for the post-processing of 3D printed parts. With the continuous expansion of the application field of 3D printing, the requirements for cleaning process are also increasing. In the future, combined with intelligent control system and environment-friendly cleaning agent, ultrasonic cleaning technology will play a more important role in 3D printing industry, helping to realize higher quality and higher efficiency manufacturing process.