Disadvantages of electric toothbrushes before welding：

1. Before the adoption of ultrasonic welding technology, the manufacturing of electric toothbrushes faced many difficult problems that were hard to overcome, which seriously affected the product quality and user experience.

2. In terms of structural integrity, the assembly method made the connections between key parts such as the brush head and the brush handle, and the battery compartment not firm enough. During use, frequent vibrations and daily collisions could easily cause these parts to become loose, displaced, or even separated. Imagine the brush head suddenly shaking while brushing teeth, not only greatly reducing the cleaning effect but also making people feel extremely uncomfortable. Moreover, the unstable and loose connection structure would affect the overall stability of the electric toothbrush, greatly shortening the product's service life.

3. In terms of sealing performance, there were obvious shortcomings. Electric toothbrushes inevitably come into contact with water during daily use, but assembled electric toothbrushes are difficult to be completely sealed. Moisture can easily seep inside, corrode electronic components, and cause malfunctions such as short - circuits. Once the internal circuit is damaged, the electric toothbrush may experience problems such as insufficient power, functional disorders, or even be directly scrapped. This not only brings economic losses to users but also causes waste of resources due to frequent product replacements.

When ultrasonic welding technology is applied to the manufacturing of electric toothbrushes：

4. In terms of structural stability, ultrasonic welding achieves a firm combination of key parts such as the brush head and the brush handle, and the battery compartment. The fusion at the molecular level greatly improves the connection strength. Even after long - term use and frequent vibrations, the parts remain tightly connected and will not become loose or separated. This ensures the efficient and stable operation of the electric toothbrush during the cleaning process, providing users with a consistent high - quality cleaning experience.

5. Excellent sealing performance is also a major highlight of ultrasonic welding. The welded electric toothbrush can achieve an excellent waterproof effect, completely preventing the intrusion of moisture. Whether it is splashing water during daily toothbrushing or soaking when cleaning the electric toothbrush, it will not cause any damage to the internal electronic components. This not only extends the service life of the electric toothbrush but also greatly reduces the probability of product failures, making users feel more at ease when using it.

6. In terms of appearance, ultrasonic welding makes the appearance of the electric toothbrush more delicate and perfect. Without gaps, burrs, and splicing marks left, the entire product has smooth lines and a smooth surface, presenting a simple and high - end texture.