Analysis of Joint Leakage in Variable Geometry Die


Analysis of Joint Leakage in Variable Geometry Die



Sean M Conway


This poster reflects research conducted as part of a course project designed to give students experience in the research process.



This project presents a computational analysis of multiple joint types used in variable geometry dies that enable the extrusion of polymer plastic parts with a varying cross sectional area. Polymer extrusions account for nearly half of all manufactured plastic parts due to it being a high production and low cost process. Traditional polymer extrusion is limited to fixed dies that produce plastic products of continuous cross-sectional area defined by the die exit profile. A variable geometry die allows the cross-sectional area of the extruded polymer part to vary while being extruded. To allow for a change in shape, multiple links move around various joints. Clearances in the joints are required for the joints to properly function and to be able to properly manufactured the joints. These clearances create leakage paths for the melted polymer to escape through and potentially damage the quality of the plastic part. Computational fluid dynamics models have been constructed and used to assess the effect of the various clearance sizes on the leakage through the joints. The goal of this analysis is to optimize the clearance require in the geometry of the joints.

Publication Date


Project Designation

Course Project - Graduate

Primary Advisor

Andrew P. Murray, David H. Myszka

Primary Advisor's Department

Mechanical and Aerospace Engineering


Stander Symposium project

Analysis of Joint Leakage in Variable Geometry Die