Comparative analysis of gas-assisted extrusion of polypropylene sheet based on two types of gas intake

Abstract

The formation of a stable gas layer is to have a significant effect on polymer gas-assisted extrusion (GAE). Previously, for vertical extrusion forming, the gap intake method was used, which tends to result in very short stabilization times for the gas layer. In this study, the effect of two gas intake modes was compared based on horizontal sheet extrusion. The results show that stabilization of the gas layer is easily achieved in the vertical gas-assisted die by introducing gas first. However, when using parallel die, the gas distributes the melt uniformly along the surrounding velocity and the gas layer can be stable for a long time. Moreover, disrupting the process sequence also makes it easy to achieve gas layer stability without affecting the tability of the gas layer in the subsequent extrusion. And, during low-speed extrusion, the flow inertia of the polymer melt is used to extend the flow channel of the gas-free–assisted section into the gas-assisted section to overcome the gravity of the polymer melt and smoothly extrude it in the parallel gas-assisted die. The parallel die can be considered for the production of GAE of daily profiles and can be used to improve quality.

Research on Gas-Assisted Extrusion of Elastic Material Round-Tube for Flexible Robot Body

“…The manufacturing technology based on gas-assisted extrusion (GAE) forming is mostly used for the processing and manufacturing of round tubes, square tubes, and irregular shapes, which has the advantages of high production efficiency and relatively simple secondary processing procedures. In this study, the GAE method − is intended to be used to manufacture the flexible robot body. The evolution of GAE forming technology dates back to the 1960s when it was predominantly used for extruding polyethylene foam plastics.…”