Effect of variable infill density on mechanical behaviour of 3-D printed PLA specimen: an experimental investigation

Abstract

Fused deposition modelling (FDM) is one of the additive manufacturing technique, widely accepted due to its 'easy to use' technology. The set process parameters during FDM printing, affect the mechanical behaviour of the built part. The objective of this study is to investigate the effect of variable infill density on the tensile and impact strength of polylactic acid (PLA) specimens printed by an open-source 3D printer. The tensile and impact test specimens are printed according to the DIN EN ISO 527-2, ASTM D256 (Izod) and ASTM D6110 (Charpy) respectively. A computerised tensometer and impactometer used to conduct the tensile and the impact strength of the PLA specimens. The tensile strength with the highest value of 46.3 N/mm 2 and the lowest value of 29.9 N/mm 2 are found. The results demonstrate that the specimens with varying infill density exhibit better tensile strength than the specimens with single infill density. The varying infill density specimens weigh lighter as compared to single infill density, which saves the raw material. The highest Charpy and lowest Izod strength found to be 4.72 kJ/m 2 and 1.7 kJ/m 2 . The impact test experimental data establishes that impact strength is directly proportional to the infill density. Thus, by varying the infill density, there is a reduction in the impact strength of the printed specimens.

Infill Density Influence on Mechanical and Thermal Properties of Short Carbon Fiber-Reinforced Polyamide Composites Manufactured by FFF Process

“…Samples with a 75% infill have a smaller maximum displacement (2.22 mm) than those with 50% (2.28 mm) even if the maximum sustained load (4.03 kN) is higher than that at a 50% infill (3.56 kN). It has been demonstrated [ 21 ] that the outer layers (shell), which are denser, provide a resistance to crack propagation. Under action load, during failure of the sample, the cracks propagate from shell to core (inner layers) [ 21 , 36 ].…”

“…The results concluded that an 85% infill density for each infill pattern demonstrated the highest energy absorption. In [ 21 ], Tanveer et al investigated the impact strength of the PLA samples with 50%, 70%, and 100% infill densities. The authors concluded that impact strength is direct proportional to infill density percentage.…”

3 Boyutlu Basılı PLA Numunelerinin İç Mimarisinin Mekanik Davranışı Üzerindeki Etkilerinin Deneysel İncelenmesi

“…The mechanical properties of each filling type were determined by taking the average of 5 tests. Some studies in the literature say that mechanical strength is directly proportional to the filling ratio [1,15,16]. It is obvious that the 100% filling ratio will increase the printing cost by increasing the raw material and production time.…”

“…Fused deposition modeling (FDM) is an additive manufacturing (AM) method commonly used for the creation of three-dimensional solid objects by enabling computer-generated models to be converted cheaply, quickly and easily into physical parts. FDM stands out with its features such as being cheaper than other AM printing technologies, being easier to maintain and having lower hardware costs [1]. FDM technologies offer rapidly developing and promising solutions in many areas of healthcare.…”

The influence of process parameters on the impact resistance of 3D printed PLA specimens under water-absorption and heat-treated conditions

“…Kuczko et al (2014) found that the impact strength of FDM-based samples is lesser than the parts fabricated by injection moulding. Tanveer et al (2019) measured the impact strength of PLA specimens having 50%, 70% and 100% infill density and concluded that the impact strength is directly proportionate to infill density. The study predicted that the higher material packing density enhances the impact resistance and reduces the stress intensity factor.…”