scholarly journals Microstructure and Mechanical Performance of 3D Printed Wood-PLA/PHA Using Fused Deposition Modelling: Effect of Printing Temperature

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1778 ◽  
Author(s):  
Guessasma ◽  
Belhabib ◽  
Nouri

The microstructure and mechanical performance of wood-based filament is investigated in the case of Fused Deposition Modelling (FDM) technique using experimental and numerical approaches. The printing process of wood-PLA/PHA is conducted by varying the printing temperature, typically from 210 °C to 250 °C. The filament temperature during the laying down is measured using infra-red camera to study the thermal cycling. In addition, X-ray micro-tomography is used to evaluate the material arrangement of printed wood-PLA/PHA at different length scales. Tensile experiments are performed to rank the loss in mechanical performance with respect to the filament properties. Finally, finite element computation is considered to predict the tensile behaviour based on the implementation of the real 3D microstructure issued from X-ray micro-tomography. The results show that the wood-based filament is printable over a wide range of temperatures and exhibits a marked heat accumulation tendency at high printing temperatures. However, the limited gain in tensile performance at these temperatures makes 220 °C an optimal choice for printing wood-based filament. The elongation at break of 3D-printed wood-PLA/PHA is remarkably similar to the results observed for the filament. Finite element computation reveals that despite this apparent similarity, the associated deformation mechanisms are different.

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1220 ◽  
Author(s):  
Sofiane Guessasma ◽  
Sofiane Belhabib ◽  
Hedi Nouri

Polyethylene terephthalate glycol (PETG) is a thermoplastic formed by polyethylene terephthalate (PET) and ethylene glycol and known for his high impact resistance and ductility. The printability of PETG for fused deposition modelling (FDM) is studied by monitoring the filament temperature using an infra-red camera. The microstructural arrangement of 3D printed PETG is analysed by means of X-ray micro-tomography and tensile performance is investigated in a wide range of printing temperatures from 210 °C to 255 °C. A finite element model is implemented based on 3D microstructure of the printed material to reveal the deformation mechanisms and the role of the microstructural defects on the mechanical performance. The results show that PETG can be printed within a limited range of printing temperatures. The results suggest a significant loss of the mechanical performance due to the FDM processing and particularly a substantial reduction of the elongation at break is observed. The loss of this property is explained by the inhomogeneous deformation of the PETG filament. X-ray micro-tomography results reveal a limited amount of process-induced porosity, which only extends through the sample thickness. The FE predictions point out the combination of local shearing and inhomogeneous stretching that are correlated to the filament arrangement within the plane of construction.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1060
Author(s):  
Sofiane Guessasma ◽  
Sofiane Belhabib ◽  
Abdullah Altin

The influence of the microstructural arrangement of 3D-printed polylactic acid (PLA) on its mechanical properties is studied using both numerical and experimental approaches. Thermal cycling during the laying down of PLA filament is investigated through infra-red measurements for different printing conditions. The microstructure induced by 3D printing is determined using X-ray micro-tomography. The mechanical properties are measured under tensile testing conditions. Finite element computation is considered to predict the mechanical performance of 3D-printed PLA by converting the acquired 3D images into structural meshes. The results confirm the leading role of the printing temperature on thermal cycling during the laying down process. In addition, the weak influence of the printing temperature on the stiffness of 3D-printed PLA is explained by the relatively small change in porosity content. However, the influence of the printing temperature on the ultimate properties is found to be substantial. This major influence is explained from finite element predictions as an effect of pore connectivity which is found to be the control factor for tensile strength.


2021 ◽  
Vol 27 (3) ◽  
pp. 465-474
Author(s):  
Martin Krčma ◽  
David Škaroupka ◽  
Petr Vosynek ◽  
Tomáš Zikmund ◽  
Jozef Kaiser ◽  
...  

Purpose This paper aims to focus on the evaluation of a polymer concrete as a three-dimensional (3D) printing material. An associated company has developed plastic concrete made from reused unrecyclable plastic waste. Its intended use is as a construction material. Design/methodology/approach The concrete mix, called PolyBet, composed of polypropylene and glass sand, is printed by the fused deposition modelling process. The process of material and parameter selection is described. The mechanical properties of the filled material were compared to its cast state. Samples were made from castings and two different orientations of 3D-printed parts. Three-point flex tests were carried out, and the area of the break was examined. Computed tomography of the samples was carried out. Findings The influence of the 3D printing process on the material was evaluated. The mechanical performance of the longitudinal samples was close to the cast state. There was a difference in the failure mode between the states, with cast parts exhibiting a tougher behaviour, with fractures propagating in a stair-like manner. The 3D-printed samples exhibited high degrees of porosity. Originality/value The results suggest that the novel material is a good fit for 3D printing, with little to no degradation caused by the process. Layer adhesion was shown to be excellent, with negligible effect on the finished part for the longitudinal orientation. That means, if large-scale testing of buildability is successful, the material is a good fit for additive manufacturing of building components and other large-scale structures.


2021 ◽  
Vol 30 ◽  
pp. 263498332110000
Author(s):  
Helge Schneevogt ◽  
Kevin Stelzner ◽  
Buket Yilmaz ◽  
Bilen Emek Abali ◽  
André Klunker ◽  
...  

Herein, the effects of recycled polymers on the mechanical properties of additively manufactured specimens, specifically those derived by fused deposition modelling, are determined. The intention is to investigate how 3D-printing can be more sustainable and how recycled polymers compare against conventional ones. Initially, sustainability is discussed in general and more sustainable materials such as recycled filaments and biodegradable filaments are introduced. Subsequently, a comparison of the recycled filament recycled Polyethylene terephthalate (rePET) and a conventional Polyethylene terephthalate with glycol (PETG) filament is drawn upon their mechanical performance under tension, and the geometry and slicing strategy for the 3D-printed specimens is discussed. Finally, the outcomes from the experiments are compared against numerically determined results and conclusions are drawn.


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