Feasibility and process optimization of PLA–PETG dissimilar supports in FFF
Antonio Bacciaglia, Alessandro Ceruti, Alfredo LiveraniPurpose
Additive manufacturing enables complex geometries, but support structures still compromise surface quality, increase postprocessing effort and cause material waste. This study aims to evaluate the feasibility and process optimization of a dual-material support strategy using polylactic acid (PLA) and polyethylene terephthalate glycol (PETG) on a single-head fused filament fabrication (FFF) system, with the objective of improving surface quality and support removability while preserving mechanical performance.
Design/methodology/approach
An experimental campaign was conducted using PETG parts fabricated with PLA as an interfacial support material. Surface quality was assessed through roughness measurements, while mechanical performance was evaluated via tensile tests and digital image correlation. Manufacturing time, material consumption and ease of support removal were also quantified and compared with conventional single-material PETG printing.
Findings
The introduction of a PLA interfacial layer significantly improved surface quality and support removal. Surface roughness anisotropy was reduced by up to 99% in vertically printed specimens and 86% in horizontally printed ones compared to single-material PETG. Supports were easily removed without surface damage. Ultimate tensile strength decreased by approximately 20% in vertical specimens and 49% in horizontal specimens, whereas the secant modulus showed limited variation (<10%). Manufacturing time and material usage increased by 57% and 35%, respectively, due to material purging during switching. Finally, the force required to remove the supports completely dropped by 63% on average from the single-material to the dissimilar-material configuration.
Practical implications
The proposed approach is suitable for prototypes and functional parts where surface quality and dimensional consistency are critical, especially when only single-nozzle machines are available.
Originality/value
This study demonstrates a practical and effective multimaterial support strategy using dissimilar polymers on a single-head FFF machine, offering an alternative to soluble supports and multiextruder systems.