the present invention generally relates to polymeric materials pulverisation . more particularly , the present invention relates to an extrusion method and device for producing particulate deformed polymers having a more useful resultant devulcanised surface area for downstream industrial usage . specifically , the present invention relates to a pulverisation extrusion method and device that utilises the herein described specific combination of variable feed screw torque and variable main screw speed together with coupled temperature control of the extruder barrel and extruder main screw .