Mechanical properties of 3D printed parts: Effect of ultraviolet PLA filaments ageing and water absorption

Abstract

In additive manufacturing, fused deposition modelling (FDM) is one of the most often-used technologies. Polylactic Acid (PLA) is the most frequently applied polymer for prototyping or for real uses. This study mainly focuses on the mechanical properties of PLA parts printed with filament exposed to UV light to mimic the effect of recycled filament. Three radiation periods were studied, respectively, 24 h, 48 h and 72 h. Tensile tests were carried out to characterize the influence of building orientation (On flat/on-edge) and raster angles (0°, 45°, 90°, 0°/90°, −45°/+45°). Failure modes were also discussed. Printed specimens were subjected to water absorption to assess the mechanical properties in real application. Generally with the same raster angle, the interlayer structure of specimens manufactured in on-edge orientation has greater adhesion than the specimens in flat orientation. The results show that mechanical properties are lower in case of flat building orientation and the raster angle has the same trend in both orientations. Elsewhere, edge orientation exhibited lower water absorption thanks to the inwall that protected the printed part. UV radiation enhances the interface between printed layers for the lower period. The mechanical properties were affected by the degradation of the bulk material in the direction of 90°.

Development of fiber-reinforced polylactic acid filaments using untreated/silane-treated trichosanthes cucumerina fibers for additive manufacturing

“…Also, the increased surface area with long-term immersion in water increases the water penetration of the composites in addition to the higher fiber contents, as seen in 9UT, with a swelling of 3.353%. 31

Figure 3.Water absorption behavior of TC fibers/PLA 3D Printing Filaments.

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“…30 Another fact is that these shrinkages are due to the operating parameters and influence of gravity, but here the operating parameters remain constant (low speed and high temperature). 31

Figure 1.Diameter deviation of TC fibers/PLA 3D printing filaments.

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Analysis of tensile behavior of Nylon-CF fabricated using material extrusion

“…Various studies are conducted to analyze the effect of processing parameters on the mechanical properties of AM parts. 4,7–11 Being th emost valuable mechanical property, the researchers have tried to extensively investigate the tensile behaviour of MEX parts 12 including in various environment conditions 13 and structures. 14…”

“…Various studies are conducted to analyze the effect of processing parameters on the mechanical properties of AM parts. 4,[7][8][9][10][11] Being th emost valuable mechanical property, the researchers have tried to extensively investigate the tensile behaviour of MEX parts 12 including in various environment conditions 13 and structures. 14 The drawback of polymers printed through MEX is that the mechanical performance is usually lower than injection-molded parts of the same polymer.…”

The Effect of Ultraviolet Radiation on Mechanical Properties of Fused Deposition Modeling 3D Printed Materials

“…The study [14] focuses on analyzing and discussing the aging treatment impact on the mechanical properties and failure modes of printed specimens made from polylactic acid (PLA) filament. The researchers examine how the UV treatment applied to the PLA filament prior to printing impact the performance and characteristics of the printed specimens.…”