The feed section establishes solids convey in the same ways as a conventional screw. At the beginning of the transition (compression) zone, a second flight is started. This flight separates the solids channel from the melt channel. As material progress down the transition, melting continues as the solids are pressed and sheared against the barrel, forming a melt film, the barrier flight moves under the melt film and the melt is collected in the solid pellets and melted polymer are separated and different function are performed on each.
The melt channel is deep, giving low shear and reduction the possibility of overheating the melted pellets against the barrel for efficient frictional melting, breakup of solids bed does not occur to stop this frictional melting. The solids bed continues to get shall over and finally disappears into the back side of the primary flight.