Characteristic of the extrusion of polyethylene modified with halogen free flame retardants and additives

摘要

The effects of commercial halogen free flame retardants (two grades of aluminium oxide and magnesium hydrooxide, Table 1) and three auxiliary materials acting as external lubricants (Table 2) on the course and efficiency of medium density polyethylene (PE-MD) extrusion process have been investigated. The relations between polymer pressure in the extruder head (p), screw torque (M), polymer flow rate (mass flow-G and volume flow-W) and the type and concentration of flame retardant (50-60 wt.%) anda uxiliary material (Table 3, Fig. 1 and 2) were characterized. Aluminum hydroxide Martinal OL-107c appeared to be most advantageous because it least affected the increase in p and M values. It has been stated that auxiliry materials used improved the extrusion process. The amounts of lubricants used should not exceed 0.8 wt.%