English Abstract

Unstable Flow in Polymer Processing

Mitsuyoshi FUJIYAMA
Fujiyama Polymer Research, Yamaguchi, Yamaguchi, Japan
Nippon Gomu Kyokaishi,(2015),88(10),385-390 General Review in Japanese

Several flow instabilities appear during polymer processing, particularly, in extrusion. They are melt fractures, such as, sharkskin, stick slip, gross melt fracture. Also they are abnormal melt fractures, such as, super shear, process window, and splitting. Other flow instabilities are interfacial instability in co-extrusion, bubble instability in tubular film extrusion, and draw resonance in fiber spinning, film casting and extrusion lamination. Their general characteristics and mechanisms, the control of melt fractures, and the recent trend of melt fracture studies are briefly reviewed.

Keywords: Unstable Flow, Sharkskin, Stick Slip, Gross Melt Fracture, Abnormal Melt Fracture, Interfacial Instability, Draw Resonance, Bubble Instability