Continuous mixing and shearing rolling mill

A mixing and shearing rolling mill for plasticizable material comprising:

• first and second adjacent rotatable rolls each having a face width comprising a plurality of independently controllable temperature zones, wherein at least two of said temperature zones are maintained at different temperatures, said face widths being more than four times the roll diameter and comprising a plurality of sharp-edged shear grooves arranged obliquely on the surface thereof at an acute angle and counter to each other, said grooves being separated by flights, both the number of the shear grooves on the roll circumference and the depth of the shear grooves increasing along the roll axis from the bearing side having a material throat up to the roll center and decreasing again from the roll center to the bearing side at the material discharge end,
• said first rotatable roll comprising a front, material-coated roll subdivided over the face width thereof into a plurality of sections having shear grooves dimensioned differently relative to one another, and a substantially non-grooved section at one end of the roll, said plurality of sections comprising:
• a first section disposed in a roll region of the material throat, the length of said first section corresponding to from about 25 to about 30% of the face width and having shear grooves of from about 0.5 to about 20 mm deep, and from about 1 to about 40 mm wide;
• an adjacent second section having a length which corresponds to from about 35 to about 40% of the face width, the depth of the shear grooves in said second section being reduced continuously to approximately half the value of the depth of the shear grooves in said first section, and
• a third section disposed adjacent to said second section, said third section having a length which corresponds to from about 25 to about 30% of the face width, and wherein the depth of the shear grooves of said third section are substantially the same as the depth of the shear grooves of said second section at the adjacent end thereof, said third section being disposed adjacent to said non-grooved section at one end of the roll, said nongrooved section corresponding to from about 10 to about 15% of the face width.