Mechanistic understanding of 3D printed polycarbonate process yielding comparable dielectric strength with injection molding process

Autor: Hari Prasad, Prasanta Mukhopadhyay, Nitesh Kumar Shet, Juha-Matti Levasalmi, Anshita Sudarshan, S. M. Swamy
Rok vydání: 2020
Předmět:
Zdroj: SN Applied Sciences. 2
ISSN: 2523-3971
2523-3963
DOI: 10.1007/s42452-020-2894-x
Popis: Plastic components used as insulators for electrical segments are conventionally processed by injection molding (IM). One of the important considerations in electrical safety is dielectric strength. There is a growing interest to process such components using additive manufacturing (3D printing) due to the ease of fabricating complex component designs without elaborate machinery while retaining similar property attributes. This study established a mechanistic understanding of dielectric breakdown in 3D (fused filament fabrication) printed polycarbonate. The impact of 3D printing process parameters on the dielectric performance is established. Appearance of dielectric breakdown site on the sample was found to be a good indicator of its dielectric performance. The optical imaging studies revealed that IM sample which exhibited a dielectric strength of 23.4 kV/mm (ASTM D149) was associated with a pin-centric, radially symmetric and cohesive crack measuring 450 μm at the site of dielectric breakdown. It was found that 3D printed samples exhibiting inferior dielectric strength (7.2–19.9 kV/mm) were associated with larger, elongated, radially asymmetric and non-cohesive crack lengths. An inverse correlation between dielectric strength and length of the dielectric breakdown (cracks) is elucidated in this study. The optimized print parameters resulted in a breakdown that appeared to be cohesive, radially symmetric and which ultimately correlated with an improved dielectric strength (22.4–23.2 kV/mm), at par with IM.
Databáze: OpenAIRE
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