The Influence of the Process Parameters on the Mechanical Properties of PLA Specimens Produced by Fused Filament Fabrication—A Review

Abstract

Polylactic acid (PLA) is produced from renewable materials, has a low melting temperature and has a low carbon footprint. These advantages have led to the extensive use of polylactic acid in additive manufacturing, particularly by fused filament fabrication (FFF). PLA parts that are 3D printed for industrial applications require stable mechanical properties and predictability regarding their dependence on the process parameters. Therefore, the development of the FFF process has been continuously accompanied by the development of software packages that generate CNC codes for the printers. A large number of user-controllable process parameters have been introduced in these software packages. In this respect, a lot of articles in the specialized literature address the issue of the influence of the process parameters on the mechanical properties of 3D-printed specimens. A systematic review of the research targeting the influence of process parameters on the mechanical properties of PLA specimens additively manufactured by fused filament fabrication was carried out by the authors of this paper. Six process parameters (layer thickness, printing speed, printing temperature, build plate temperature, build orientation and raster angle) were followed. The mechanical behavior was evaluated by tensile, compressive and bending properties.

The Influence of the Printing Temperature and the Filament Color on the Dimensional Accuracy, Tensile Strength, and Friction Performance of FFF-Printed PLA Specimens

“…The fixed parameters were as follows: the layer thickness (0.2 mm), targeting both acceptable values for the ultimate tensile strength (UTS) and the printing duration [ 12 ]; the build plate temperature (60 °C), as recommended by the filament producer; the printing speed (50 mm/s), higher than the value mentioned by the filament producer, in order to reduce the printing time of the samples and also considering previous research [ 12 , 23 , 24 , 26 , 31 ]; the build orientation (YX) and the raster angle (45°/−45°) for better mechanical properties [ 12 ]; and the infill density (100%), in order to minimize the influence of this parameter on the printed samples’ mesostructure.…”

“…In this connection, when targeting good-quality FFF manufactured parts with specific properties, one should take into consideration at least the following influential printing process variables [ 12 , 13 ]: The type of the filament (material, color, diameter, producer) and the storage conditions before the printing process (environmental humidity, UV-irradiation). The model design and the infill parameters (infill pattern, infill density).…”

“…The printing temperature (also referred to as the printing head temperature or the extrusion temperature) and its influence on the FDM-printed part’s quality and mechanical properties is one of the most studied process parameters. In this regard, researchers tested temperatures ranging from 175 °C to 275 °C, but the most commonly analyzed temperatures were situated between 190 °C and 220 °C [ 12 ].…”

Additive Manufacturing of Anatomical Poly(d,l-lactide) Scaffolds

“…In particular, Chacón et al [ 48 ] recently demonstrated that the tensile and three-point bending properties of PLA can be significantly tuned by acting on build orientation, layer thickness, and feed rate. Other parameters, such as extrusion head and bed temperature, as well as lay-down pattern, were demonstrated to play a significant role in the resulting material mechanical response [ 49 , 50 ]. The present experimental characterization contributes to this research trend by highlighting that infill density and lay-down pattern are two key parameters exploitable for PDLLA tensile properties tuning.…”

Multi-objective optimization and prediction of surface roughness and printing time in FFF printed ABS polymer

“…Hence, there is a need to find the optimum printing parameters to fabricate high-quality components at minimum printing time. There are several studies available related to the experimental characterization of FFF printed ABS polymer 39 – 42 . However, the studies related to multi-objective optimization techniques and WASPAS ranking for predicting and optimizing the FFF process printing parameters of polymers using statistical analysis tools are limited.…”