# Influence of Form Factor on Microstructural, Mechanical and Electrical Properties of Electrically Conductive Polyvinylidene Fluoride Processed by Arburg Plastic Freeforming

## TL;DR

This study examines how the shape of printed structures affects the mechanical and electrical properties of a conductive polymer processed using a specific 3D printing method.

## Contribution

The paper introduces an adapted analytical method to assess electrical properties and determines the optimal form factor for printing a special PVDF material.

## Key findings

- The form factor significantly influences mechanical properties due to microstructural porosity.
- An adapted analytical method successfully evaluates electrical and piezoelectric behavior.
- Optimal form factor improves dimensional precision and performance of printed PVDF components.

## Abstract

The utilization of polymer-based additive manufacturing processes for the production of functional components, consumer goods, spare parts, etc., has increased thanks to recent technological advances. The Arburg Plastic Freeforming (APF) process is a promising AM technology, in which standard plastic granules are deployed, and droplets are discharged along a track instead of using continuously extruded straws, unlike other filament-based processes, to the benefit of various industries that require good mechanical properties while maintaining dimensional precision. Due to the round shape of the droplets and tracks, however, defects such as voids can occur between individual paths during processing, which affect, most notably, mechanical properties. The electrical/ferroelectric properties of conductive/electroactive polymers are also affected. This study focuses on determining the optimal form factor for processing a special grade polyvinylidene fluoride (PVDF) material whilst other parameters, along with the ones ascertained in previous work, are kept constant. Along with tensile tests, X-ray computed microtomography (µ-CT) and scanning electron microscopy (SEM) analyses are implemented, particularly to observe microstructural porosity. Electrical properties and possible piezoelectric behavior are investigated via an originally adapted analytical method. The results provide important insights into the APF process and printing high-performance plastics with individual features, expanding the potential for further applications.