Noztek are testing a new prototype barrel and screw design intended to allow customers to mix polymers in a melted state. The barrel and nozzle are split in two sections, to allow for easy cleaning, as shown below.
We have added two re-flow valves, the front valve shuts off the flow of polymer to the nozzle and the rear valve allows the material to flow back into the barrel via a 3mm channel.
This initial design has been manufactured to fit onto an existing Noztek Pro or Noztek Touch extruders and can be retro fitted to the existing case using the new vertical hopper format. Instead of heater bands we now use two ceramic cartridge heaters slotted into the barrel assembly. These will be supplied in 220v and 110v.
http://www.noztek.com/product/replacement-barrel-and-screw/