Inertia Friction Method
Two workpiece parts to be joined are clamped rigidly in a sturdy fixed unit usually called the tailstock fixture and a rotating chuck assembly or collet drive.
The spindle assembly, which includes one of the workpieces and any required flywheels, is rapidly accelerated to a pre-calculated speed, storing the energy required for welding.
The spindle is disconnected from the drive source and begins to freewheel. At the same time, the ram assembly moves the non-rotating part axially to force both workpieces together, also a predetermined calculated (lbs.) thrust load.
While the workpieces are thrust tightly together, friction between the interfaces convert kinetic energy stored in the rotating spindle and flywheel assemblies into heat at the interface, and finally into mechanical working of the plastic metals.