03/27/2025
By Danielle Fretwell
The Francis College of Engineering, Department of Plastics Engineering, invites you to attend a Doctoral Dissertation Proposal defense by Yuvprakash Singh on: "FFF 3D Printing Beyond Prototyping: Enabling FFF 3D Printing for High-Performance and Functional Materials."
Date: Monday, April 7, 2025
Time: 1 - 3 p.m.
Location: ETIC 445
Committee:
Advisor: Jay-Hoon Park, Ph.D., Associate Professor, Plastics Engineering, UMass Lowell
Committee Members*
David Kazmer, Ph.D., Professor, Plastics Engineering, UMass Lowell
Amir Ameli, Ph.D., Associate Professor, Plastics Engineering, UMass Lowell
Abstract:
Fused filament fabrication (FFF) is one of the most common material extrusion additive manufacturing techniques, which has gained popularity due to its ease of operation and low setup cost. However, despite the wide acceptance of this 3D printing technique, due to weak mechanical strength and limited feed material compatibility, applications of fabricated parts are often limited to prototyping. Thus, not truly harnessing the benefits offered by additive manufacturing like freedom of design and low manufacturing costs.
To address this fundamental challenge, current research efforts are being focused on increasing the strength and incorporating functionalities to the fabricated parts. However, due to a few fundamental challenges like weak interlayer adhesion, poor electrical conductivity and structural instability, these advances have ceased to reach the stage wherein applications of these parts could be used in demanding applications. The objective of this Ph.D. dissertation is to work towards eliminating weak interlayer adhesion in vertical prints to reach injection molded strengths, evaluating effect of crystallinity on printability and fabricating electrically conductive parts. These attempts are in contribution to making FFF-based additive manufacturing more functional as well as more accessible to highly crystalline polymers, which make up a majority of the thermoplastics currently produced by volume.
In pursuit of this goal, three aims are proposed: Aim 1 focuses on reaching injection molding strengths in FFF-printing of high-performance plastics via optimized annealing of vertical prints composed of core-shell polyether imide filaments; Aim 2 delves into understanding the effect of flow induced crystallization on printability of HDPE; and Aim 3 involves fabrication of tailored electrically conductive FFF prints via core-shell filament fabrication. Ultimately, this work aims to present a pathway to making FFF a desired manufacturing technique, which can offer its benefits to real-life applications.