Effects of Vibration Force Field on Extensiona! Stress of Polymer Melt in Contraction Die

摘要

Electromagnetic dynamic plasticating extrusion, as one of main novel forming methods, has many important benefits to the forming process and the properties of its products. Here a visualization technique of flow induced birefringence was used to study the effects of the vibration parameters of screw on the extensional stress in contraction die. It is shown that , the extensional stress vibrate with the screw vibration at the same frequency;;the amplitude of the extensional stress increases with the amplitude of the screw increasing;;the average extensional stress at dynamic extrusion is less than that without vibration force, and it decreases with the screw vibration frequency or amplitude increasing.