Utilisation of forest industry wastes in polylactic acid-based composite manufacturing via 3D printing technology

Abstract

This study aims to screen locally available forestry industry residues as reinforcing fillers for polylactic acid (PLA)-based composites processed via three-dimensional (3D) printing technology. The mechanical, thermal, and morphological properties of 3D-printed PLA composites reinforced with wood flour (WF), kraft lignin (KL), birch inner bark flour (BF), and microcrystalline cellulose (MCC) were investigated. The materials were produced from blends containing 10 wt% of each additive. In addition, the effect of the coupling agent on WF-containing items was studied. As a special objective, biochar was studied as a natural black pigment for PLA-based composites. The PLA used in this research was an industrial-grade material adapted for 3D printing, which was found to be suitable for further modification if needed. According to the results, fillers can significantly improve composite stiffness while maintaining strength close to that of neat PLA. Additionally, the printability of the composites was like that of neat PLA, with no noticeable printing errors observed under microscopy.

Keywords: 3D printing; PLA; composites; wood flour; lignin; bark; MCC; biochar; mechanical properties