Centrifugal extrusion apparatus which heat plastifies material by mechanical shearing action

A centrifugal extruder adapted to receive particulate heat plastifiable material, heat plastify and discharge the material in heat plastified form, the centrifugal extruder comprising

• a generally hollow discoidal rotor, the hollow discoidal rotor defining
• a material receiving opening in communication with
• a generally discoidal material receiving cavity,
• a plurality of peripherally disposed extrusion openings, the extrusion openings being in full communication with the material receiving cavity, the material receiving cavity having a generally double tapered cross-sectional configuration when the cross-section is taken in a plane containing the axis of rotation, the cavity having a maximum dimension adjacent the axis of rotation in a direction normal to the plane of rotation of the rotor and a minimum dimension in a direction normal to the plane of rotation of the rotor at a location remote from the axis of rotation,
• a shear means disposed within the material receiving cavity, the shear means being a generally planar shearing element defining spaces to permit particles of heat plastifiable material to distribute themselves on either side of the shearing element, the shearing element being adapted to rotate coaxially relative to the housing and having peripheral portions which approximate the diameter of the material receiving cavity, the shearing element being in spaced relationship to a surface of the housing defining the cavity and the extrusion orifices,
• means operatively associated with the rotor to rotate the rotor and
• means operatively associated with the shearing element to rotate the shearing element in a like direction, the rotor and the shearing element being rotatable relative to one another to thereby apply shear to a particulate heat plastifiable material within the rotor, the shear causing the particulate material to become heat plastified and centrifugal force causing the heat plastified material to be discharged from the extrusion openings.