The ultrasonic absorption ability of PVC material: Although PVC material has a certain ultrasonic absorption ability, its absorption rate is relatively low. This means that during the welding process, the heat generated by PVC material may not be sufficient to meet the ideal welding requirements, resulting in poor welding efficiency.

The thermal stability of PVC: PVC is prone to softening and degradation at high temperatures (<150 ° C). Excessive heating during ultrasonic welding can affect the welding strength and even lead to welding failure. Therefore, it is necessary to strictly control the welding power and time to avoid excessive temperature rise of PVC in the welding area.

The molecular structure of PVC: The molecular chains of PVC are relatively straight, and their dense arrangement limits the formation of small holes and chemical bonds during ultrasonic welding. This affects the formation of chemical bonds at the welding interface, further affecting the welding strength.

Surface characteristics of PVC: The surface of PVC is relatively smooth, and it is difficult for ultrasound to generate strong diffusion and focusing on its surface, which is not conducive to the formation of deeper molten pools and thus affects the welding effect.

In order to improve the effectiveness of ultrasonic welding of PVC materials, it may be necessary to choose higher power and appropriate amplitude to adapt to the characteristics of PVC materials. At the same time, some modifiers such as hot melt adhesives can also be added to PVC materials to enhance the bonding at the welding interface. In addition, for certain specific PVC materials or structures, other welding methods such as hot plate welding or high-frequency welding may be required to achieve better welding results.