Page 44 - MSAM-3-3

Materials Science in

Additive Manufacturing

ORIGINAL RESEARCH ARTICLE
Material extrusion-based printing optimization

of recycled HDPE filaments made from used milk
jugs

Soek Po Phillis Teng 1,2 , Chor Hiong Tee 1 , Hwee Boon Tan ,
2
and Kah Fai Leong *
2,3
1 Physical Education and Sports Science Academic Department, National Institute of Education,
Nanyang Technological University, Singapore
2 School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
3 Singapore Centre for 3D Printing, Nanyang Technological University, Singapore

Abstract

Fused deposition modeling printing is a material extrusion (MEX) process that
has gained popularity over the years due to its increased affordability and greater
versatility. There is a wide variety of MEX printing technologies and a broad
spectrum of materials that can be 3D printed, ranging from metallic to non-metallic
materials. MEX has emerged as the most common technology in consumer-grade,
desktop 3D printers for printing thermoplastics, such as acrylonitrile butadiene
styrene (ABS) and polylactic acid. High-density polyethylene (HDPE) is a widely
used thermoplastic material for product packaging. The sheer availability of
recyclable or recycled HDPE (rHDPE) from used packaging has led to efforts to
*Corresponding author: apply it in MEX printing. However, rHDPE presents challenges as a filament material,
Kah Fai Leong
(mkfleong@ntu.edu.sg) including issues such as part detachment from the print bed and high warpage.
The focus of this study is to determine the optimal conditions that can mitigate,
Citation: Teng SPP, Tee CH,
Tan HB, Leong KF. Material if not eliminate, the print bed adhesion problems associated with printing rHDPE
extrusion-based printing filaments. This was achieved by conducting a series of tests to address these
optimization of recycled HDPE challenges, including part removability relating to the shear strength of print bed
filaments made from used milk
jugs. Mater Sci Add Manuf. adhesion to identify the necessary range of print bed adhesion and corresponding
2024;3(3):4084. parameters.
doi: 10.36922/msam.4084
Received: June 29, 2024
Keywords: Material extrusion; Fused deposition modeling; Recycling; Additive
Accepted: August 8, 2024 manufacturing; 3D printing; High-density polyethylene
Published Online: September 6, 2024
Copyright: © 2024 Author(s).
This is an Open-Access article 1. Introduction
distributed under the terms of the
Creative Commons Attribution Global plastic production has exponentially increased over the past 50 years.
License, permitting distribution,
and reproduction in any medium, Unfortunately, most plastics degrade at an incredibly slow rate and are often classified
provided the original work is as non-biodegradable. This presents a significant sustainability concern as natural
properly cited. resources deplete and plastic waste continues to occupy substantial space in landfills and
1,2
Publisher’s Note: AccScience consume energy in incinerators. This issue is particularly pronounced in a small nation
Publishing remains neutral with like Singapore. At the current rate of waste disposal, Singapore’s only remaining landfill,
regard to jurisdictional claims in 3
published maps and institutional the Semakau landfill, is projected to reach full capacity by 2035. This situation has been
affiliations. exacerbated further by China’s ban on importing 24 types of solid waste, including

Volume 3 Issue 3 (2024) 1 doi: 10.36922/msam.4084