an apparatus for converting thermoplastic waste material into a commercial - grade granular material wherein the waste material is introduced into a chamber containing a rotating cutter which shreds and frictionally heats the thermoplastic material which is thereafter cooled by cooling water added to the material while the cutting operation continues . the cooling water or vapor is then withdrawn or exhausted from the container under negative pressure leaving the granular material dry . also , solvents are removed from the material . the cutter blade may include baffle bars which provide frictional heating surfaces for heating the thermoplastic waste material .