Foaming characterization of lightweight polylactic-acid filaments with various heating conditions to apply for additive manufacturing

Abstract This study focuses on analyzing lightweight polylactic acid (LW_PLA) filaments for additive manufacturing, using four commercially available LW_PLA filaments like PLA (Esun Co., Ltd, China), ePLA-LW (Esun Co., Ltd, China), LW-PLA (Colorfabb, Netherlands) and LW-PLA-HT (Colorfabb, Netherlands) to evaluate their 3D printing conditions. Thermal (DSC), rheological, heating and morphological analyses were conducted at temperatures from 200 to 240 °C, including tests on 3D-printed honeycomb structures. Results show that LW_PLA_CL (LW-PLA, Colorfabb, Netherlands) and LW_PLA_HT (LW-PLA-HT, Colorfabb, Netherlands) have superior foamability, dimensional stability and consistent viscoelastic properties, especially above 220 °C, compared with PLA and LW_PLA_ES. Both filaments maintained uniform expansion and low loss factors, making them highly suitable for lightweight foamed applications. This work fills a research gap by systematically linking foaming behavior with printability and provides clear guidelines for 3D printing process conditions for LW_PLA at 230 °C and 240 °C to achieve stable, high quality 3D printed materials.