dc.contributor.author | Costanzo, Andrea | |
dc.contributor.author | Spotorno, Roberto | |
dc.contributor.author | Candal, María Virginia | |
dc.contributor.author | Fernández San Martín, Mercedes | |
dc.contributor.author | Müller Sánchez, Alejandro Jesús | |
dc.contributor.author | Graham, Richard | |
dc.contributor.author | Cavallo, Dario | |
dc.contributor.author | McIlroy, Claire | |
dc.date.accessioned | 2021-03-30T17:09:00Z | |
dc.date.available | 2021-03-30T17:09:00Z | |
dc.date.issued | 2020-06-30 | |
dc.identifier.citation | Additive Manufacturing 36 : (2020) // Article ID 101415 | es_ES |
dc.identifier.issn | 2214-8604 | |
dc.identifier.uri | http://hdl.handle.net/10810/50832 | |
dc.description | Unformatted post-print version of the accepted article | es_ES |
dc.description.abstract | Gaining a molecular understanding of material extrusion (MatEx) 3D printing is crucial to predicting and
controlling part properties. Here we report the direct observation of distinct birefringence localised to the weld
regions between the printed filaments, indicating the presence of molecular orientation that is absent from the
bulk of the filament. The value of birefringence at the weld increases at higher prints speeds and lower nozzle
temperatures, and is found to be detrimental to the weld strength measured by tensile testing perpendicular to
the print direction. We employ a molecularly-aware non-isothermal model of the MatEx flow and cooling process
to predict the degree of alignment trapped in the weld at the glass transition. We find that the predicted residual
alignment factor, A, is linearly related to the extent of birefringence, Δn. Thus, by combining experiments and
molecular modelling, we show that weld strength is not limited by inter-diffusion, as commonly expected, but
instead by the configuration of the entangled polymer network. We adapt the classic molecular interpretation of
glassy polymer fracture to explain how the measured weld strength decreases with increasing print speed and
decreasing nozzle temperature. | es_ES |
dc.description.sponsorship | This research was funded by the Royal Society Exchange Scheme. The authors would like to acknowledge Michela Chiappalone for contributing to experimental measurements. The UPV/EHU team and D. Cavallo gratefully acknowledge funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 778092. RSG acknowledges funding from the EPSRC (EP/P005403/1.). CM acknowledges funding from the Royal Commission for the Exhibition of 1851. | es_ES |
dc.language.iso | eng | es_ES |
dc.publisher | Elsevier B.V | es_ES |
dc.relation | info:eu-repo/grantAgreement/EC/H2020/778092 | es_ES |
dc.rights | info:eu-repo/semantics/openAccess | es_ES |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/3.0/es/ | * |
dc.subject | material extrusion | es_ES |
dc.subject | birefringence | es_ES |
dc.subject | molecular orientation | es_ES |
dc.subject | weld strength | es_ES |
dc.subject | polylactic acid | es_ES |
dc.title | Residual alignment and its effect on weld strength in material-extrusion 3D-printing of polylactic acid | es_ES |
dc.type | info:eu-repo/semantics/article | es_ES |
dc.rights.holder | (c) 2020 Elservier, this manuscript version is made available under the CC-BY-NC-ND 4.0 | es_ES |
dc.relation.publisherversion | https://www.sciencedirect.com/science/article/pii/S2214860420307879 | es_ES |
dc.identifier.doi | 10.1016/j.addma.2020.101415 | |
dc.contributor.funder | European Commission | |
dc.departamentoes | Ciencia y tecnología de polímeros | es_ES |
dc.departamentoeu | Polimeroen zientzia eta teknologia | es_ES |