Co-rotating dual speed multi-screw extruder and processing method thereof

A processing method of a co-rotating dual speed multi-screw extruder, comprising:

• rotating a first screw and a second screw co-rotationally at dual speeds to push materials forward in an inner cavity of a barrel;
• generating heat to melt the materials, by the rotating of the first screw and the second screw, and meanwhile, a first step structure arranged on the first screw and a second step structure arranged on the second screw being meshed in a meshing zone to stir and forcibly peel the materials, to make the materials become a melt;
• wherein a cross-sectional contour of the first screw comprises multiple curve arcs, and the multiple curve arcs on the cross-sectional contour of the first screw comprise multiple circular arcs and multiple non-circular curve arcs;
• wherein a cross-sectional contour of the second screw also comprises multiple curve arcs, and the multiple curve arcs on the cross-sectional contour of the second screw also comprise multiple circular arcs and multiple non-circular curve arcs;
• wherein a number of the multiple curve arcs on the cross-sectional contour of the second screw is twice that of the multiple curve arcs on the cross-sectional contour of the first screw;
• wherein the multiple curve arcs on the cross-sectional contour of the first screw are asymmetrical, and the multiple curve arcs on the cross-sectional contour of the second screw are centrosymmetric;
• and
• wherein a rotating speed ratio of the first screw to the second screw is 2;
• performing plasticizing mixing on the materials which become a melt under a strong elongation action and a strong disturbance action generated by periodic meshing of the first step structure and the second step structure in the meshing zone in a staggered manner;
• extruding the materials which become a melt out from an outlet stably;
• and
• realizing self-cleaning, by the first screw and the second screw wiping with each other.