The influence of 3D printing parameters on the mechanical properties

The influence of 3D printing parameters on the mechanical properties of 3D models

The BCN3D Epsilon W50 printer was used for the research, using commonly used materials in this technology: PLA, PETG and ABS. The assessment of mechanical strength was carried out using uniaxial tensile tests, taking into account various parameters. The entire study involved testing a total of 495 samples, in accordance with the UNE-EN ISO 527-2 Type 1A standard, according to the plastic molding or extrusion test model.

It is expected that increases in extrusion temperature, density and wall number will result in printed parts with improved properties. As a result, higher printing speeds and reduced layer heights could potentially lead to reduced mechanical strength, although the exact extent of their impact remains uncertain.

Main assumptions of the analysis of samples from the Epsilon W50 printer

Infill Type: Grid infill is said to offer higher strength compared to Gyroid and Triangular infills due to its interconnected grid structure.

Fill Density: Higher fill density is expected to help increase mechanical strength, as more material in the part should improve its ability to withstand stress.

Layer height: It is believed that a lower layer height will adversely affect the mechanical strength due to poor adhesion between layers.

Print Speed: Increased print speeds are expected to result in lower part quality due to extrusion instability and less effective bonding between layers, potentially reducing mechanical strength.

Print Temperature: A higher printing temperature range is expected to improve bonding between layers, thereby increasing the mechanical strength of the part. In turn, lower temperatures can lead to cold extrusion with material loss.

Number of walls: It is believed that a larger number of walls will significantly increase the mechanical strength of the printed parts, providing greater structural stability.

Analysis results of samples from the Epsilon W50 printer

In the next section, the graphs present various results and conclusions.

The influence of the type of filling

Analyzing the data obtained and seeing that, depending on the material, each type of filling works differently, we can conclude that the pattern does not have a significant impact on the final properties of the part. While it is true that ABS and gyroid filled PETG test samples show the highest loads, the differences and variability compared to PLA make it impossible to conclude that this type of filling is the best in terms of improving mechanical properties. Therefore, the assumption with which this test was started, expecting better results from mesh filling, then triangular filling, and finally gyroidal filling, is incorrect.

Influence of filling density

Analyzing the results obtained, we can conclude that the assumption made before the test was correct. In other words, the mechanical properties of parts increase as density increases. This thesis is much more pronounced in the case of PLA and PETG, while in the case of ABS it is much less noticeable, to the point of not increasing tensile strength between samples with 60% fill and those with 80%. This may be due to the type of polymer structure each material creates, with PLA and PETG being materials with a crystalline structure, while ABS has a more amorphous structure. Furthermore, we can also state that increasing the density of ABS printed parts by more than 60% does not guarantee greater mechanical strength.

Influence of layer height

As expected, the increase in layer height provides better properties for the printed parts. This is due to the fact that, as mentioned earlier, there are fewer "weak spots" throughout the part. The weak points are the joints of each printed layer, because the adhesion between the layers will never have the same mechanical strength as the material itself.

The influence of printing speed

After analyzing the data, we conclude that just as higher printing speeds increase instability in the extrusion of the material and therefore increase the possibility of imperfections in the printed part, leading to weaker mechanical strength, there is also a lower limit to this printing speed. This means that it is not true that a lower printing speed leads to a higher mechanical strength. Each material has an optimal operating temperature range for printing. If the operating temperature is below this range, the material will be cold extruded, while if the printing temperature is above this range, the material may degrade, crystallizing its polymer structure and causing abnormal extrusion.

Summary of sample analysis from the Epsilon W50 printer

Analysis of the impact of 3D printing parameters on the mechanical properties of parts provides important information for the industrial and engineering industries. Understanding how different settings affect mechanical strength allows you to optimize your manufacturing processes and select the best parameters for specific applications.

The conclusions from this study emphasize the importance of carefully selecting 3D printing parameters, such as fill density, layer height and print speed , to obtain the desired mechanical properties in the printed parts. Further research and experiments are necessary to better understand the comprehensive impact of various factors on the final quality and durability of printed elements.