Solid state shear extrusion pulverization

A process for solid state shear extrusion pulverization of a polymeric material of the type which thermally softens at a lower temperature than its melting temperature comprising;

• heating said polymeric material to a pre-melt softening temperature below its melting point, cooling the heated polymeric material from said pre-melt softening temperature and applying by generally converging conically shaped counter-rotating meshing screws normal and shear forces sufficient to form fine powder of said polymeric material, and fluidizing said fine powder in a gas stream preventing its agglomeration.

In a process for solid state pulverization by shear extrusion, the improvement comprising;

• fluidizing pulverized powder in a gas stream following said pulverization thereby preventing its agglomeration.

A process for enhancement of reactivity of polymeric and solid monomeric material comprising in sequence;

• heating said material to a pre-melt or softening temperature, cooling said material and applying normal and shear forces sufficient to form fine powder of said material, and fluidizing said powder in a gas stream preventing its agglomeration.

A process for enhancement of reactivity of polymeric and solid monomeric material comprising in sequence;

• heating said material to a pre-melt or softening temperature, cooling said material and applying by generally converging conically shaped counter-rotating meshing screws normal and shear forces sufficient to form fine powder of said material, and fluidizing said powder in a gas stream preventing its agglomeration.

In an apparatus for solid state shear extrusion pulverization of solid material, the improvement comprising;

• means for fluidizing pulverized powder in a gas stream following said pulverization thereby preventing its agglomeration.

An apparatus for solid state shear extrusion pulverization of polymeric material comprising;

• a hollow generally converging barrel having a large end and an opposite small end housing a generally converging twin screw extruder having generally converging conical meshing screws in at least a powder formation zone, feed means for feeding said polymeric material to a first zone at said large end of said barrel, discharge means for discharging pulverized powder from a fourth zone at said opposite small end of said barrel, heating means for heating said polymeric material to a pre-melt or softening temperature below its melting temperature in a second zone adjacent said first zone, cooling means for cooling said polymeric material from said pre-melt temperature to a lower temperature and means for applying normal and shear forces sufficient to form fine powder from said polymeric material in a third zone between said second zone and said fourth zone, means for fluidizing said powder in a gas stream in at least one of said third or said fourth zones thereby preventing its agglomeration.