LAMINAR MORPHOLOGY OF EXTRUDED HDPE/PA-6 BLENDS CONTROLLED BY FLOW FIELDS

摘要

Ribbons were extruded from two high-density polyethylene (HDPE)/polyamide-6 (PA-6) blends with different melt shear viscosity ratios (VRs) of PA-6 to HDPE. Three different screw configurations, one metering and two mixing screws, and three screw speeds were evaluated to investigated their effects on the morphology of extruded ribbons. The scanning electron microscopy (SEM) observation showed that the blends with different VRs need different screw shearing intensity to yield a thin, overlapping, and discontinuous laminar PA-6 phase, which results in enhancing permeability barrier properties. The screw speed also played a distinct role in controlling the morphology of the blend. By controlling the flow fields, through appropriately combining the screw configuration with scrsw speed in this study, a well-developed laminar PA-6 phase with an aspect ratio of about 100 was obtained.