We have just begun to bench test a twin band arrangement on our standard version of the Noztek Pro. We feel that preheating the barrel just after the hopper will improve extrusion speed and help reduce the strain on the motor, giving it more longevity.
Because the standard Pro version uses internal barrel friction to generate pressure, this extra heat should allow a much wider variety of polymers to be extruded. We are hoping to also test a range of metal alloy powders soon, which are currently being extruded with the high temperature version.
Both bands are currently being controlled by a single PID, or in the case of the Noztek Touch, a controller on the PCB board, meaning that both heater bands will heat up to the same temperature, but we are already developing a new board with multiple controllers allowing each band to heated independently. This set up would certainly help when experimenting with different types of thermoplastics .