The internal skeleton of the plush toy is not welded:

1. Loose structure and easy to deform: The components of the skeleton are not welded, so the connection is not firm. When played with or squeezed, the components are likely to shift, causing the overall shape of the toy to become distorted, affecting its aesthetics and user experience.

2. Poor durability: The loose connection method makes the skeleton prone to falling off or breaking, especially under frequent contact or stress, greatly shortening the service life of the toy.

3. Potential safety hazards: The unwelded skeleton components may become loose and fall off. If swallowed by children or if they come into contact with sharp edges, it may pose a safety risk.

After ultrasonic welding:

4. Firm and stable connection: Through ultrasonic welding, the components of the skeleton are closely combined, can withstand certain external extrusion and pulling, and are not easy to deform or loosen, maintaining the shape of the toy for a long time.

5. Improved durability: The welded joints have high strength, reducing the occurrence of the skeleton falling off or breaking, extending the service life of the plush toy and reducing the probability of damage.

6. Higher safety: The welded skeleton has a compact structure without loose parts, avoiding safety hazards such as accidental ingestion caused by parts falling off, making it more suitable for children to use.