ABSTRACT

Better temperature control was achieved by Enikolopyan et al. with the Brabender Plastograph; this resulted in LDPE powder with narrow particle size distribution of 25-50 microns (500-270 mesh) [5,26]. Later attempts were made to develop a continuous grinding process using the co-rotating twin-screw Berstorff extruder and the rotary grinder based on a single-screw extruder; in the latter, the gap between the grinding rotor and the cylinder could be varied to obtain narrow particle size distribution [11,27,28]. It was observed through a special window that fine grinding of LDPE occurred during cooling of the melt or after heating of the feedstock material at the optimum temperature; particle size remained unchanged during several passes through the device [11,29].