Anisotropy of poly(lactic acid)/carbon fiber composites prepared by fused deposition modeling

Abstract

It is well known that 3D printed parts prepared by fused deposition modeling (FDM) exhibit large anisotropy of mechanical properties. In this article, poly(lactic acid; PLA)/carbon fiber (CF) composites with different built orientations (X, Y, Z) were prepared by FDM. The effects of printing temperature, speed, orientations, and layer thickness on the mechanical properties of the composites were systematically investigated. The mechanical properties of PLA/CF composites show more significant anisotropy. The orientation of the fibers along the printing direction is displayed by scanning electron microscopy. Printing parameters bring almost no effect on mechanical properties of the X‐construct oriented specimen, and bring obvious effect on those of the Y‐construct oriented specimen and Z‐construct oriented specimen. According to the analysis, carbon fiber can amplify this anisotropy from layer fashion, and the key factors from printing parameters are porosity and bond strength between fuses. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48786.

Fused Deposition Modelling of Fibre Reinforced Polymer Composites: A Parametric Review

“…This leads to lower tensile strength in the "upright" direction of the short fibre reinforced sample compared to the "up-right" orientation of neat polymers [47][48][49]. The weakness of "up-right" orientation of chopped CF/PLA was compared to the "flat" by Ding et al [50]. The tensile strength of the "flat" and "up-right" orientation in the article is approximately 52 MPa and 35 MPa, respectively.…”

FDM-Based 3D Printing of Polymer and Associated Composite: A Review on Mechanical Properties, Defects and Treatments

“…To identify the effect of printing orientation, layer thickness and the printing temperature, Ding et al [ 152 ] carried out an experiment using a CF/PLA composite printed using the FDM process. The orientation of the specimens is present in Figure 7 b for better clarification.…”

“… ( a ) Short CF immersed in Nylon matrix (onyx filament) [ 148 ]. ( b ) The orientation of the printed tensile specimens [ 152 ]. …”

Influence of fused filament fabrication parameters on tensile properties of polylactide/layered silicate nanocomposite using response surface methodology

“…The poor filament adhesion would increase the anisotropy of the printed part by lowering the mechanical properties in the building direction. 21 Other phenomena might also influence the effect of temperature on mechanical properties, such as crystallinity 10,22 or matrix degradation, 23 and cause a more difficult understanding of this thermal behavior. Printing speed and temperature are thought to interact, since printing speed can modify the time between two adjacent depositions, which is the time allowed for a filament to weld before the temperature falls below the glass transition.…”

“…Regarding extrusion temperature, Spoerk et al 20 reported a positive effect, since an increase in temperature decreases viscosity and promotes filament adhesion. The poor filament adhesion would increase the anisotropy of the printed part by lowering the mechanical properties in the building direction 21 . Other phenomena might also influence the effect of temperature on mechanical properties, such as crystallinity 10,22 or matrix degradation, 23 and cause a more difficult understanding of this thermal behavior.…”