Heather M. Smith



Download Full Text (978 KB)


Conventional polymer extrusion is a common manufacturing process in which plastic resin is melted and pulled through a fixed-geometry die plate to produce a shape. This process creates long parts with a uniform cross-sectional area, including pipes, molding, and window frames. Shape-changing dies would expand the capabilities of extrusion by allowing the cross-sectional area to change over the length of the extruded part. This would allow for parts manufactured more quickly and at a lower tooling cost, as compared to other processes such as injection molding. A constant extruder screw speed is desired throughout the process due to the pellets being melted by friction within the screw. As the area of the orifice changes throughout the extrusion, problems arise which may be pacified by varying the line speed, or tracking differences between the final shape and the exit area of the part. The goal of this project is to design a series of variable extrusion dies that exhibit significant changes in area. Three types of die were created, each evaluating a different strategy, including bypass ports and shape modifying features beyond the die exit. The dies have recently been produced, installed, and tested to evaluate the various features of each design.

Publication Date


Project Designation

Independent Research

Primary Advisor

Andrew P Murray, David H Myszka

Primary Advisor's Department

Mechanical and Aerospace Engineering


Stander Symposium poster


Arts and Humanities | Business | Education | Engineering | Life Sciences | Medicine and Health Sciences | Physical Sciences and Mathematics | Social and Behavioral Sciences

Variable Extrusion Dies that Exhibit Significant Change in Exit Area