Experimental study on the determination of reduced compressive properties of FFF-printed enhanced PLA specimens

Abstract. Mechanical parts used in industrial applications should be able to comply not only with rigorous requirements regarding dimensional accuracy and surface quality, but also possess adequate mechanical strength in order to achieve a long service life. Additive manufacturing (AM) processes are considered nowadays an alternative way to produce high-performing parts with complex geometries and different types of materials with high efficiency. Especially in the case of polymers, Fused Filament Fabrication (FFF) is a well-established choice for creating high quality parts at an affordable cost when optimal parameters are used for the printing process. Although a lot of studies have been carried out in order to optimize the parameters of FFF process for the increase of individual mechanical properties, often neglecting the effect of infill density on these properties, it is proposed that the use of reduced mechanical properties, by normalizing them by part weight, can provide more generalized findings and deeper insight into the correlations between process parameters and mechanical behavior. Thus, in the present work, compression test specimens were fabricated by FFF technique under various infill density and layer height values for three different infill patterns, and the fundamental compressive properties such as Young’s Modulus, strength and absorbed energy were determined. After statistical analysis was carried out, the role of each parameter on the improvement of reduced mechanical properties was identified.