Electrically Conductive Polyetheretherketone Nanocomposite Filaments: From Production to Fused Deposition Modeling

Abstract

Abstract:The present work reports the production and characterization of polyetheretherketone (PEEK) nanocomposite filaments incorporating carbon nanotubes (CNT) and graphite nanoplates (GnP), electrically conductive and suitable for fused deposition modeling (FDM) processing. The nanocomposites were manufactured by melt mixing and those presenting electrical conductivity near 10 S/m were selected for the production of filaments for FDM. The extruded filaments were characterized for mechanical and thermal conductivity, polymer crystallinity, thermal relaxation, nanoparticle dispersion, thermoelectric effect, and coefficient of friction. They presented electrical conductivity in the range of 1.5 to 13.1 S/m, as well as good mechanical performance and higher thermal conductivity compared to PEEK. The addition of GnP improved the composites' melt processability, maintained the electrical conductivity at target level, and reduced the coefficient of friction by up to 60%. Finally, three-dimensional (3D) printed test specimens were produced, showing a Young's modulus and ultimate tensile strength comparable to those of the filaments, but a lower strain at break and electrical conductivity. This was attributed to the presence of large voids in the part, revealing the need for 3D printing parameter optimization. Finally, filament production was up-scaled to kilogram scale maintaining the properties of the research-scale filaments.

Experiment-Based Process Modeling and Optimization for High-Quality and Resource-Efficient FFF 3D Printing

“…When looking at the regression prediction model for surface roughness (R a ) across the X-Y plane traversed in the X direction (see Equation (5) and Figure 11), it was noticeable that the surface inclination angle had the most significant influence on the obtainable roughness, followed by layer thickness, which is supported by the results obtained using ANOVA, which identified the three most significant parameters, such as first, surface inclination angle (p-value = 0.0031), second, layer thickness (p-value = 0.0051), and third, printing speed (p-value = 0.4316).…”

“…When looking at the regression prediction model for surface roughness (Ra) across the X-Y plane traversed in the X direction (see Equation (5) and Error! Reference source not found.…”

“…AM offers increased design freedom, lead-time reductions, and the possibility of functional integration, with AM technologies being increasingly adopted and developed by industry, resulting in more varied and affordable processes, accompanied by greater market acceptance and penetration [1][2][3]. In particular, 3D printing has become a viable alternative to conventional manufacturing processes in numerous applications, i.e., in the automobile, aerospace, medical, and construction industries and widely in furniture production [4][5][6][7]. Especially in the aerospace sector, parts previously manufactured by traditional means are being replaced by additively manufactured low-weight polymer components.…”

“…industries and widely in furniture production [4][5][6][7]. Especially in the aerospace sector, parts previously manufactured by traditional means are being replaced by additively manufactured lowweight polymer components.…”

Influence of Manufacturing Parameters and Post Processing on the Electrical Conductivity of Extrusion-Based 3D Printed Nanocomposite Parts

“…Some authors [20] have developed electrically conductive filament composite for AM by mixing polyetheretherketone (PEEK), carbon nanotubes and graphite nanoplates, obtaining an electrical conductivity in the range of 1.5-13.1 S/m. The inclusion of graphite nanoplates reduced the coefficient of friction by up to 60%, keeping the electrical conductivity.…”