First of all depends, if you want to maufacture filaments of large scale then you need to use twin screw extruder.
If at academic/ research scale, use brabender to mix the material components to develop a feedstock. Further, palletize the feedstock into 2-3 mm using cutter mill. Then use single screw extruder to produce filaments of approprite diameter using adequate processing parameters.
Thanks for the information. I already tried exact filament dia.was not achieved. Any portable machine is available in the market for research like 3Devo.
Kindly elaborate on the specific single screw extruder you used to fabricate highly filled filaments?
I already fabricated small-scale printable filaments at 3Devo and Filabot. With careful extrusion and optimized parameters, you will be able to achieve the required filament diameter.