SUSTAINABLE CONDUCTIVE RPLA-CARBON BLACK FILAMENT FOR ADDITIVE MANUFACTURING VIA SINGLE-SCREW EXTRUSION

Authors

• Zaidan Faraby Zulkarnain, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai 81310, Johor Bahru, Malaysia
• Shakina Hawapi, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai 81310, Johor Bahru, Malaysia
• Aini Zuhra Abdul Kadir, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai 81310, Johor Bahru, MalaysiaFollow
• Muhd Ikmal Isyraf Mohd Maulana, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai 81310, Johor Bahru, Malaysia
• Nor Akmal Fadil, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai 81310, Johor Bahru, Malaysia
• Najlaa Nazihah Mas’ood, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai 81310, Johor Bahru, Malaysia
• Mohd Rizal Alkahari, Faculty of Mechanical Engineering, Universiti Teknikal Malaysia Melaka (UTeM), Hang Tuah Jaya, 76100, Ayer Keroh, Melaka, Malaysia
• Saidin Wahab, Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia Batu Pahat, 86400, Malaysia

Abstract

The growing demand for low-cost, sustainable conductive filaments for additive manufacturing motivates the exploration of recycled polymer feedstocks as alternatives to virgin materials. However, the effects of prior thermal reprocessing on both the electrical performance and morphological integrity of recycled PLA (rPLA)–carbon black (CB) composite filaments remain insufficiently characterised, particularly under single-screw extrusion conditions. This study fabricates and characterises conductive filaments from virgin PLA and rPLA, each loaded with CB at 0.2, 0.6, and 1.0 wt%, using a low-cost desktop single-screw extruder. Melt blending was found to be essential for achieving continuous filament extrusion, as ball milling produced insufficient filler dispersion and frequent nozzle jamming. Electrical conductivity increased markedly with CB content, with both systems approaching percolation onset at 1.0 wt%, where conductivity reached 0.369 mS/m for PLA-CB and 0.362 mS/m for rPLA-CB. SEM and EDX analyses revealed that rPLA exhibited incomplete cross-sectional filling and a higher surface O/C ratio, both consistent with chain-scission-induced molecular degradation while quantitative agglomerate size analysis showed rPLA-CB produced larger and more heterogeneously distributed CB clusters compared to PLA-CB. Despite these microstructural differences, rPLA-CB achieved comparable electrical performance to its virgin counterpart, demonstrating its viability as a sustainable feedstock for semiconductive and antistatic additive manufacturing applications.

Keywords

recycled PLA; filament extrusion; dimensional stability; carbon black; conductive additive manufacturing

Publication Date

2026

Received Date

15 Aug 2025

Revised Date

20 May 2026

Accepted Date

24 June 2026

Recommended Citation

Zulkarnain, Zaidan Faraby; Hawapi, Shakina; Kadir, Aini Zuhra Abdul; Mohd Maulana, Muhd Ikmal Isyraf; Fadil, Nor Akmal; Mas’ood, Najlaa Nazihah; Alkahari, Mohd Rizal; and Wahab, Saidin (2026) "SUSTAINABLE CONDUCTIVE RPLA-CARBON BLACK FILAMENT FOR ADDITIVE MANUFACTURING VIA SINGLE-SCREW EXTRUSION," ASEAN Journal on Science and Technology for Development: Vol. 43: No. 2, Article 14.
DOI: https://doi.org/10.61931/2224-9028.1669
Available at: https://ajstd.ubd.edu.bn/journal/vol43/iss2/14