Some aspects of a plastics pulverization technology by extrusion

This study presents results, observations and new developments on the pulve rization of low density polyethylene (LDPE) by a nontraditional technology. A twin screw conical counter-rotating extruder, a mixer head with roller b lades and a single screw extruder attached to a C.W. Brabender PL2000 Plast i-Corder were utilized as pulverization apparatuses. The pulverization phen omenon was studied over a wide range of shear rates and at resin processing temperatures below and above the Vicat softening point, i.e., at solid and soft (visco-elastic/rubbery-like) state of the material. A hypothesis abou t the pulverization mechanism of LDPE at a temperature between melting/crys tallization temperature and Vicat softening point is presented.