Due to their molecular structure or physical properties, the following materials are generally not suitable for standard ultrasonic welding.

1: Thermosetting plastics:

Such as epoxy resins and phenolic resins. When heated, these materials undergo chemical cross-linking and cure, and cannot be remelted; therefore, they cannot be welded using ultrasonic welding.

2: Soft or elastomeric plastics:

TPE/TPU: Too soft; they absorb vibration energy, making it difficult to generate sufficient heat.

Silicone rubber: Completely unsuitable.

3: Materials with extremely high melting points or those insensitive to vibration:

Fluoroplastics: Such as PTFE, which has an extremely low coefficient of friction and does not absorb energy.

Polyimide: Melting point is too high.

4: Complex-structured or fiber-filled materials:

Glass-fiber-reinforced plastics: During welding, the glass fibers prevent the plastic from fusing and cause severe wear on the welding tip. Welding is possible, but it causes significant damage to the tip and results in limited strength.

Highly mineral-filled plastics: Similarly, the fillers prevent fusion.