Characterisation and Modelling of PLA Filaments and Evolution with Time
| Autor: | Ana Ferrández-Montero, Jose Ygnacio Pastor, Begoña Ferrari, Jaime Orellana Barrasa |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
FDM Polymers and Plastics Organic chemistry Crosshead Article Protein filament chemistry.chemical_compound QD241-441 Polylactic acid Ultimate tensile strength Composite material Elastic modulus logistic model strain rate analytical models General Chemistry Strain rate printing temperature thermo-mechanical properties extrusion chemistry ageing PLA Extrusion Glass transition |
| Zdroj: | Polymers Volume 13 Issue 17 Polymers, Vol 13, Iss 2899, p 2899 (2021) |
| ISSN: | 2073-4360 |
| DOI: | 10.3390/polym13172899 |
| Popis: | The properties of polylactic acid (PLA) filaments have not yet been analysed in detail, and they are strongly affected by the extrusion process used in some additive manufacturing systems. Here we present the mechanical, thermal, physical, and fractographical properties of an extruded filament (not the bulk material or scaffolds), the basic building block of any PLA structure printed via material extrusion. This research aims to create a reference point for the modelisation of additively manufactured structures via extrusion processes, as the main building block is characterised in detail for a deep understanding. Furthermore, we investigated the natural ageing (up to one year), the effect of the printing (extruding) temperature (180 and 190 °C), and the effect of the crosshead speed during the tensile tests (10−1 to 102 mm/min) to provide a deeper analysis of the material. The results showed that the material extruded at 190 °C performed better than the material extruded at 180 °C. However, after one hundred days of natural ageing, both materials behaved similarly. This was related to the flow-induced molecular orientation during the extrusion. The crosshead rate produced a logarithmic increase of the mechanical properties, consistent with the Eyring model. Additionally, the ageing produced significant changes in both the elastic modulus and the yield strength: from 2.4 GPa and 40 MPa, in one-day-aged samples, up to 4 GPa and 62 MPa once entirely aged. Finally, it was observed that the glass transition and the enthalpic relaxation increased with ageing, agreeing with the Kohlraushch–William–Watts model. |
| Databáze: | OpenAIRE |
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