Integrated Evaluation of Electrical Breakdown Strength and Mechanical Properties of 3D-Printed Polymers, Supplemented by ImageJ-Based Surface Damage Analysis

Fused deposition modelling (FDM) is being increasingly considered for manufacturing electrically insulating components with complex geometries; however, the relationship between mechanical performance and dielectric breakdown behaviour of common printable polymers remains insufficiently understood. This study investigates the electrical insulation potential of five FDM-printed thermoplastic polymers—ABS, PLA, PETG, ASA, and PC/ABS—by evaluating their dielectric breakdown strength and mechanical properties. Specimens were fabricated using fused deposition modelling and tested according to standardised procedures: dielectric breakdown strength was measured in accordance with IEC 60243, and tensile properties were determined following ASTM D638. Surface damage produced during breakdown events, including holes and carbonised regions, was quantified using ImageJ analysis. The results were evaluated comparatively to identify the advantages and limitations of each material for electrical insulation applications. Among the tested materials, PLA exhibited the highest mechanical strength and the lowest surface damage area, whereas ABS demonstrated the highest dielectric breakdown strength. These findings highlight the trade-offs between mechanical and dielectric performance in material selection for 3D-printed insulators, and they demonstrate that ImageJ-based damage analysis serves as a valuable supplementary tool for characterising breakdown behaviour.