Nexxus MIXING is a module designed to receive the melt delivered by an upstream source (e.g. Nexxus MELTING or a conventional extruder) through a special die which spreads a thin melt film over the mixing rotor and combine with fillers or fibers, which fall down to the melt film through a vertical feed port. After combining, melt and fillers are intensively co-mixed according to the geometry of the mixing chamber.

Looking to the cross section, the red colored melt enters in the mixing chamber, spread over the rotor, in a clockwise direction and fills up the mixing chamber up to a certain circumferential level, depending on the processing target. Downstream, the pumping section provides to discharge the melt through the exit die (extrusion die, Nexxus DEGASSING or others).

The spreading die can be easily replaced to achieve the desired film thickness over the rotor (e.g. from 0,1 to 1 mm).

The filling degree of the mixing chamber defines the mixing time which equals the ratio of the accumulated melt volume(Vol) to the volumetric flow rate(Qvol) (Rt=Vol/Qvol)
It is evident that mixing work increases vs mixing time which at turn depends on the filling factor of the chamber, for given material and operative conditions.
The mixing chamber, similarly to all other Nexxus modules, is fully encased into the internal bush wall. The bush can be easily demounted and replaced either for maintenance reasons or for changing the mixing geometry.
The internal bush wall can be designed with different patterns to privilege the type of mixing required by the application. The figures below show some different patterns:
Single taper bush, for one
elongational step
Triple taper bush, for three
consecutive elongational steps
Multiple patterned taper bush,
for simultaneous distributive and
dispersive mixing
The bush geometry can be designed as to achieve high quality composites, and for example long fiber reinforced or micro vs nano particles dispersions, etc.
Below a line for production of GF reinforced PP or PA pellets is shown. Fibers well tested in our laboratory unit are for example: glass, carbon, aramid, PET, or natural like jute or kenaf..
The capability of Nexxus MIXING module to discharge a high mechanical energy without forcing the fibers to follow a tortuous path with many right angle deviations, is one explanation why Nexxus is able to well disperse fibers without breaking down nor shorten.
The Nexxus MIXING module can receive the fibers in different length, either chopped by means of dosing units or endless from bobbins.
Line for fabrication of kenaf reinforced panels or pellets

Generally the composite tends to retain the same fiber length as fed (e.g. 3 to 10 mm) .

When bobbins are used at the feed port, then a chopper directly installed top feed port provides cutting at the desired length. A proprietary software installed in the PLC makes possible to automatically control the feed rate of fibers sourcing from bobbins, electronically without installing weighing devices. The loading percent as well as the allowable fiber length depend closely on the fiber type and the application. A special upgrade for Fiber Reinforced Composites application (bottone FIBERPREG) can be found in the Special Application section.
Feeding group for kenaf bobbins and spreader
Feeding group for automotive recycled PET fibers bobbins @ 2014 Nexxus Channel All rights reserved / P.Iva 03001710122 / Design and develop: