Flow Stability and Thickness Uniformity in Continuous Extrusion

Abstract

For continuously extruded products, such as sheet and profile extrusions, thickness uniformity is a key quality factor, and it is directly linked to flow oscillations or flow disturbances at the die. Many sources of flow oscillations in the extrusion system are identified, and methods are shown on how to configure the melt delivery system to minimize their transmission to the die. These methods are illustrated with a model based on the theory of hydraulic transients.

Keywords

Stability flow thickness transient oscillations hydraulic transients pulsations uniformity model.

Get full access to this article

View all access options for this article.

References

Derezinski, S.J. Dynamic Torque of a Single Screw Extruder, Society of Plastic Engineers, Proceedings, ANTEC 2001, pp. 244-256.

Derezinski, S.J. Stability of Two-stage Single Screw Extruders, Society of Plastic Engineers , Proceedings, ANTEC 2002, pp. 312-317.

Derezinski, S.J. Multi-staged Vented Extrusion Screw with Dual Channel Depth Pumping Section , U. S. Patent 6,513,963 (February 4, 2003).

Streeter, Victor L. and Benjamin Wylie, E. (1967). Hydraulic Transients , McGraw-Hill Book Company.

Derezinski, S.J. Calculating Surge Dampening in Melt Delivery Systems, Society of Plastic Engineers , Proceedings, ANTEC 1997, pp. 341-346.