Infrared welding and ultrasonic welding are two different methods of joining plastics. The main difference between the two is the source of energy used to create heat.

Infrared welding uses infrared radiation to heat and melt the plastic parts to be joined. A halogen lamp or another source of infrared radiation is used to create heat, which is directed onto the joint area. The plastic parts absorb the heat, which causes them to melt and fuse together.

Ultrasonic welding, on the other hand, uses high-frequency vibrations to create heat. A horn is used to apply pressure to the joint area, while at the same time, high-frequency vibrations are applied. These vibrations cause friction between the two plastic parts, which generates heat and melts the plastic, fusing the parts together.

In terms of process speed, infrared welding is typically slower than ultrasonic welding. This is because it takes time for the heat to penetrate the plastic parts, and the heat has to be applied for a longer time to ensure a complete weld. Ultrasonic welding, on the other hand, can create a weld in a matter of seconds, making it a faster process.

Overall, both infrared welding and ultrasonic welding have their advantages and disadvantages, and the choice of method depends on the specific application and the materials to be joined.