Continually mixing and kneading device with two or more screws for a plasticizable material

Claim 1

A continually operating device for homogeneously mixing components of a plasticizable material, said device comprising in combination: a casing having a discharge end; an input zone in said casing including two unidirectionally rotatable meshing parallel screw elements each having several threads for mixing components of the material fed into said input zone and conveying the mixed components toward the discharge end of the casing; a dispersion zone disposed in the casing downstream of said input zone, said dispersion zone including two parallel meshing rotatable dispersion elements each having several threads for dispersing components received therein from the input zone and conveying the resulting mixture toward the discharge end of the casing; and a mixing zone disposed in the casing downstream of and adjacent to said dispersion zone, said mixing zone including two coacting parallel screw elements, said screw elements in the mixing zone having fewer threads than the dispersion elements in the dispersion zone whereby flows of material delivered from the dispersion zone to the mixing zone are combined so as to reduce the number of delivered flows in the latter zone thus effecting intensive mixing of the material in the mixing zone.