Parallel twin screws can be devided into heterodromy and homodromy according to how they rotate. They can also be devided into meshing type and non- meshing type. Then, meshing type can be devided into full meshing type and partial meshing type. Compared with a single screw,a twin screw has the advantages like strong conveying and mixing capacity, good self-cleaning and high efficiency.

Scope of application:the filling, blending, modificati on, enhancement of plastic &rubber and engineer ing resin, devolatilization of chlorinated polypropylene and super absorbent resin, extrusion of degradable masterbach, polyamide and polyurethane, granulation of carbon dust and magnetic powder, manufacturing of insulation material for cables, sheath material, low-smoke and low-halogen flame retardant type PVC cable material and silane crosslinked material.