In Ultrasonic welding, high frequency sound energy is used to bring the joining surfaces of two thermoplastic parts to a molten state where they can be permanently welded together.

1.The horn, under pressure from the assembly stand, contacts one of the two mated plastic parts.

2.Vibrational energy from the horn causes the contacted plastic part to vibrate against its mate.

3.The mechanical vibration of one part against the second causes frictional heat, which melts the plastic parts at their interface and allows the two surfaces to molecularly fuse together.

4.After a short cooling time, a permanent, homogeneous weld results.