STUDIES ON THE THEORY OF SINGLE SCREW PLASTICATING EXTRUSION .1. A NEW EXPERIMENTAL-METHOD FOR EXTRUSION

An extruder specially designed for the study of the single-screw plasticating extrusion process was constructed. Its barrel is equipped with glass windows which are located on both sides of it so that the full process of plasticating extrusion, solid conveying, melting, and melt conveying, can be clearly observed and recorded with photos and video recordings through the transparent windows. The solid profile X/W, the velocity of the solid bed V(sz), the forming positions of the upper melt film and the melt pool, and the position at which the break-up of solid bed occurs, was easily determined with good accuracy. Many dynamic characters of the plasticating extrusion, such as the non-plus solid conveying, the process of the break-up of the solid bed and the disappearance of the broken pieces of solid, were also observed in the experiments.