No abstract

Fused filament fabrication (FFF) is one of the most common 3D printing techniques having considerable potential in various fields such as pharmaceutical, medical, aerospace, and automotive. One of the impediments of FFF components is their lower mechanical performance compared with those from conventional fabrication methods. This work aims to investigate the effect of adding nanoclay due to being nontoxic to the biodegradable polylactic acid (PLA) polymer matrix for medical applications. PLA granules were melt-compounded by a twin-screw extruder with nanoclay at 2 and 4 wt.%, and then, PLA and PLA/nanoclay filaments were produced using a single-screw extruder. An L9 orthogonal array of the Taguchi approach was utilized as the design of the experiment tool to study the process in detail considering nanoclay content, nozzle temperature and raster angle as material and processing parameters. The dispersion of nanoclay in the PLA matrix was assessed by X-ray diffraction test. The results indicated that the tensile strength was enhanced by 4.6% and 15.3% using the addition of 2 and 4 wt.% of nanoclay, respectively. The microscopic observations showed that the bonding between the rasters and between the contours and rasters was improved by increasing the temperature, and consequently, led to higher tensile strength values. The results revealed that the tensile strength of 38.9 MPa was obtained at the optimum condition.

The benefits of the fused filament fabrication (FFF) method, including its simplicity, affordability, and accessibility, have made it the most commonly used additive manufacturing technique. Polylactic acid (PLA) is the most widely used material in FFF, but its use has been limited by low mechanical properties and a small processing window. To address this, PLA composites are used to improve its properties. Correlating mechanical properties with process parameters is crucial for producing high-quality composite parts. This study investigated the effects of material and process parameters on mechanical properties, such as tensile strength and elongation-at-break, using a customized Delta Rostock FFF printer. Two types of filaments were used, pure PLA and PLA/Aluminum composites. Printing speed (10, 20, and 30 mm/s) and raster angle (0/90, −45/45, and −30/60) were selected as process input parameters. The Taguchi method was used for the experiment design, and signal-to-noise ratio analysis was used for statistical optimization. The optimal values for achieving maximum tensile strength of 61.85 MPa and maximum elongation-at-break of 17.7% were determined. Furthermore, the signal-to-noise ratio analysis indicated that the filament type had the greatest influence on the tensile strength, whereas printing speed had the greatest impact on the elongation-at-break.