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Authors Joshua M. Pearce
Published 2019
License CC-BY-SA-4.0
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  • Niklas Kretzschmar, Sami Lipponen, Ville Klar, Joshua M. Pearce, Tom L. Ranger, Jukka Seppälä, and Jouni Partanen. Mechanical Properties of Ultraviolet-Assisted Paste Extrusion and Postextrusion Ultraviolet-Curing of Three-Dimensional Printed Biocomposites. 3D Printing and Additive Manufacturing. 6(3) 127-137, 2019. open access

Three-dimensional (3D) printing of biomaterials has the potential to become an ecologically advantageous alternative compared with conventional manufacturing based on oil-derived polymer materials. In this study, a novel 3D printing technology is applied that combines ultraviolet (UV) curing with paste extrusion. This hybrid manufacturing technique enables the fabrication of complex geometries from high filler-ratio pastes. The developed biocomposite aims for suitable mechanical properties in terms of tensile and compressive strength. It is composed of acrylic acid, cellulose acetate, α-cellulose, and fumed silica with a cellulose ratio of more than 25 vol-%. The material is extruded with an in-house-developed 3D printer equipped with a 12 W UV light curing source, which enables concurrent curing and extrusion. Two different UV-curing strategies were tested: postcuring without concurrent curing and postcuring with concurrent curing. The total UV-curing duration was kept constant with all samples. Tensile testing in accordance with ASTM standard D638-14 Type 4, compression testing according to ASTM D695-15, and overhang tests were conducted. As a result, samples without notable shrinkage, suitable tensile strength (up to 17.72 MPa), competitive compression testing parameters (up to 19.73 MPa), and an enhanced overhang angle (increase of more than 25°) were produced, leading to new applications and more freedom in design due to higher possible unsupported overhangs when using UV-curing during the print. Overall, constant UV light radiation during the print leads to improved mechanical properties due to the possibility of bypassing the UV-penetration depth constraint. It should be considered when extruding photopolymer-based composites, especially for large and complex components with a low degree of translucency.

Keywords[edit | edit source]

   3D printing; Mechanical testing; Natural fibre ; Natural fibre composites; Biopolymers; UV-assisted paste extrusion; biocomposite; 3D printing; mechanical properties; overhang testing; open-source platform

See also[edit | edit source]

News[edit | edit source]

  1. Finland: Aalto University Researchers Experiment with Paste Extrusion & UV Curing of 3D Printed Biocomposites - 3D Print 64k
  2. Esperimento di ricercatori dell’Università di Aalto in Finlandia con estrusione di paste e polimerizzazione UV di biocompositi stampati in 3D- Stampare in 3D
  3. Forscher der Aalto Universität experimentieren mit Pastenextrusion und UV-Härtung von 3D-gedruckten Biokompositen 3D Ruck
  4. Finland: Aalto College Researchers Experiment with Paste Extrusion & UV Curing of 3D Printed Biocomposites 3D Printing Zoom
  5. Aalto University Researchers Experiment with Paste Extrusion & UV Curing of 3D Printed Biocomposites Gyges 3D

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