Date

5-1-2019

Document Type

Thesis

Degree

Master of Science

Department

Mechanical Engineering

First Adviser

John P. Coulter

Abstract

A novel additive manufacturing technique is proposed for printing polymers with

controlled and spatially varying rheological properties. The technique, the Parallel Plates,

involves altering the flow area of the polymer melt inside the printing head and applying a

controlled shear on the polymer melt. The numerical simulations indicate that the shear

rates can be changed dramatically by confining the polymer flow to specific thicknesses.

The ability to control shear rates on the polymer melt would provide a strategy for tunable

temporal control of melt rheology, which plays a critical role in the localized evolution of

molecular orientation (for all polymers) and crystallization kinetics (for semi-crystalline

polymers) during additive manufacturing processes.

An attempt of experimentation analysis has failed due to timing scheduling difficulties.

It is recommended to follow with the experimental analysis to validate the numerically

hypothesized theory.

A numerical investigation of a novel profile extrusion technique has been done in

chapter 3 with the goal of reducing production time and cost. The technique of the

Regulated Die involves manipulating the extruded polymer into different paths with

different path diameter to control the production rate of each path. The numerical

simulations indicates the possibility of assembling such a technique physically to provide

control over the production rate of different parts using one extrusion machine.

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