Friction Welding

In the spin welding the heat necessary for the welding is produced by a rotary movement, simultaneously combined with the pressure.
One of the two parts to be welded, usually the longer one is kept fixed. The other part is put in rotation on the fixed one.
There are two types of spin welding:

•   Pivot welding
•   Inertia Welding

In the pivot type, the device that holds the rotating part is mounted with the drive shaft and simultaneously the two sides are pressed together . After finishing the welding cycle, the rotation is disengaged but the pressure continues for a bit of time, depending on the type of plastic material.

In the inertia type, the energy required for welding is first stored in a flywheel which is accelerated up to the speed required, this flywheel also carries the locking device and one of the parts to be welded. The parts are then pressed against each other and  the kinetic energy of the flywheel is converted into heat by friction, leading to the fusion of the joint.