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

Abstract

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.

Effect of printing temperature on microstructure, thermal behavior and tensile properties of 3D printed nylon using fused deposition modeling

“…Engineering stress levels as large as 250 MPa are obtained with a significant elongation at break between 151% and 169%. The elongation at break capability of nylon filament contrasts with former results obtained for PLA reinforced by wood particles 27 or hemp fibers, 28 where a limited stretching of less than 10% is observed. This limitation can be attributed to the interfacial role within the filament itself.…”

“…This means also that computations performed on the full specimen become reliable when this sample is imaged with resolutions larger than 3.6 million voxels. Based on former results published by the authors, a better stability of the predicted stiffness is obtained for materials such as wood-PLA/PHA, 27 ASA or PETG 29,30 even for voxel sizes as large as 143 μm. This larger stability of the predictions is found mainly correlated to the sensitivity of the porosity content to the change of resolution.…”

Implementing FDM 3D Printing Strategies Using Natural Fibers to Produce Biomass Composite

“…Lastly, a printing test was successfully performed with a larger printer to assess the viability of producing large-scale structures. PLA+PHA with pinewood fiber was used by Guessasamo et al [ 72 ], and the result revealed a tendency for heat accumulation at high printing temperatures. However, there was very limited improvement in the tensile performance at these temperatures, making 220 °C an ideal choice for printing the wood-based filament.…”

“…Guessasma et al [ 72 ] noticed that higher temperatures above 230 °C were not advisable, as thermal degradation of wood particles occurred between 210 °C and 370 °C, and higher temperatures affected the tensile properties. It was concluded that the elongation of printed objects at the breaking point was fully restored and a loss of mechanical performance was seen by 41% and 35% stiffness and strength, respectively, using the best printing conditions.…”

“… ( a ) The maximum tensile strength with fiber wt.% [ 30 , 34 , 35 , 38 , 39 , 40 , 41 , 42 , 44 , 47 , 51 , 62 ]. ( b ) the maximum tensile strength with fiber wt.% [ 36 , 37 , 52 , 54 , 55 , 63 , 64 , 66 , 68 , 70 , 71 , 72 ]. …”