The course of Mg(OH)2 modified polyethylene extusion process

Abstract

Medium-density PE (MFI, 0.712 g/10 min) was modified with Mg(OH)2, FR-20 grade, particle size 2.5 mm. Antiblocking and lubricating agents, 020—04, 020—15 and Lifoslip 220 PE were added as PE concetrates. Experimental extrusions in a Brabender Plastic-Corder (PLV 151 type) were carried out at screw speed 0.75 s-1, three-heating-zones temperatures 160oC, 170oC and 170oC, extruder head temperature 170oC, and extrusion velocity 1.72 mm/s. The pressure in the extruder head, the turning moment measured on the extruder screw, and the flow rate rose as the Mg(OH)2 content was increased (Figs. 1-3). With the Lifoslip agent, the pressure and the turning moment attained the lowest values. At high Mg(OH)2 contents, 57.5 and 60%, the pressure and the turning moment had values close to those attained with other auxiliary agents.