Solid state shear extrusion pulverization
AssigneeIllinois Institute of Technology
InventorsFyodor Shutov, George Ivanov, Hamid Arastoopour
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Abstract
A process and apparatus for pulverization of thermosetting, crosslinked thermoplastic and natural polymeric materials by applying normal and shear stresses by oppositely rotating meshing conical screws sufficient to form fine powder. The process may be conducted at relatively low temperatures, and in the case of many materials, at ambient or near ambient temperature and pressure conditions. The fine powder may be fluidized to aid in its discharge.
Claims32
A process for solid state shear extrusion pulverization of polymeric materials selected from the group consisting of thermosetting, crosslinked thermoplastic, natural polymers and mixtures thereof comprising;
- applying normal and shear forces by conically shaped counter-rotating meshing screws rotated at about 4 to about 90 RPM sufficient to form fine powder of said polymeric material.
An apparatus for solid state shear extrusion pulverization of polymeric materials comprising;
- a hollow generally converging barrel housing a generally converging twin screw extruder having generally converging conical meshing screws in at least the powder formation zone, feed means for feeding said polymeric material to a first zone at the large end of said barrel, discharge means for discharging pulverized powder from the opposite small end of said barrel, and generally converging conical meshing screw means for applying normal and shear forces sufficient to form fine powder from said polymeric material in a zone between said first zone and said opposite end of said barrel.
A process for solid state shear extrusion pulverization of polyurethane foam comprising applying normal and shear forces by conically shaped counter-rotating meshing screws rotated at about 4 to about 90 RPM sufficient to form fine powder of said foam.
Dependencies are inferred from the claim text.