Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive Manufacturing
Material extrusion additive manufacturing (ME-AM) techniques have been recently introduced for core–shell polymer manufacturing. Using ME-AM for core–shell manufacturing offers improved mechanical properties and dimensional accuracy over conventional 3D-printed polymer. Operating parameters play an...
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| Format: | Article |
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MDPI AG
2021-02-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/13/3/476 |
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| author | Hamid Narei Maryam Fatehifar Ashley Howard Malt John Bissell Mohammad Souri Mohammad Nasr Esfahani Masoud Jabbari |
| author_facet | Hamid Narei Maryam Fatehifar Ashley Howard Malt John Bissell Mohammad Souri Mohammad Nasr Esfahani Masoud Jabbari |
| author_sort | Hamid Narei |
| collection | DOAJ |
| description | Material extrusion additive manufacturing (ME-AM) techniques have been recently introduced for core–shell polymer manufacturing. Using ME-AM for core–shell manufacturing offers improved mechanical properties and dimensional accuracy over conventional 3D-printed polymer. Operating parameters play an important role in forming the overall quality of the 3D-printed manufactured products. Here we use numerical simulations within the framework of computation fluid dynamics (CFD) to identify the best combination of operating parameters for the 3D printing of a core–shell polymer strand. The objectives of these CFD simulations are to find strands with an ultimate volume fraction of core polymer. At the same time, complete encapsulations are obtained for the core polymer inside the shell one. In this model, the deposition flow is controlled by three dimensionless parameters: (i) the diameter ratio of core material to the nozzle, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>d</mi><mo>/</mo><mi>D</mi></mrow></semantics></math></inline-formula>; (ii) the normalised gap between the extruder and the build plate, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>t</mi><mo>/</mo><mi>D</mi></mrow></semantics></math></inline-formula>; (iii) the velocity ratio of the moving build plate to the average velocity inside the nozzle, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>V</mi><mo>/</mo><mi>U</mi></mrow></semantics></math></inline-formula>. Numerical results of the deposited strands’ cross-sections demonstrate the effects of controlling parameters on the encapsulation of the core material inside the shell and the shape and size of the strand. Overall we find that the best operating parameters are a diameter ratio of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>d</mi><mo>/</mo><mi>D</mi><mo>=</mo><mn>0.7</mn></mrow></semantics></math></inline-formula>, a normalised gap of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>t</mi><mo>/</mo><mi>D</mi><mo>=</mo><mn>1</mn></mrow></semantics></math></inline-formula>, and a velocity ratio of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>V</mi><mo>/</mo><mi>U</mi><mo>=</mo><mn>1</mn></mrow></semantics></math></inline-formula>. |
| first_indexed | 2024-03-09T06:00:17Z |
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| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-09T06:00:17Z |
| publishDate | 2021-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-8c9f116d9b424be88e05d435a910ca092023-12-03T12:09:21ZengMDPI AGPolymers2073-43602021-02-0113347610.3390/polym13030476Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive ManufacturingHamid Narei0Maryam Fatehifar1Ashley Howard Malt2John Bissell3Mohammad Souri4Mohammad Nasr Esfahani5Masoud Jabbari6Faculty of New Sciences and Technologies, University of Tehran, Tehran 1439957131, IranDepartment of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, UKHarvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USADepartment of Electronic Engineering, University of York, York YO10 5DD, UKHarvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USADepartment of Electronic Engineering, University of York, York YO10 5DD, UKDepartment of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, UKMaterial extrusion additive manufacturing (ME-AM) techniques have been recently introduced for core–shell polymer manufacturing. Using ME-AM for core–shell manufacturing offers improved mechanical properties and dimensional accuracy over conventional 3D-printed polymer. Operating parameters play an important role in forming the overall quality of the 3D-printed manufactured products. Here we use numerical simulations within the framework of computation fluid dynamics (CFD) to identify the best combination of operating parameters for the 3D printing of a core–shell polymer strand. The objectives of these CFD simulations are to find strands with an ultimate volume fraction of core polymer. At the same time, complete encapsulations are obtained for the core polymer inside the shell one. In this model, the deposition flow is controlled by three dimensionless parameters: (i) the diameter ratio of core material to the nozzle, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>d</mi><mo>/</mo><mi>D</mi></mrow></semantics></math></inline-formula>; (ii) the normalised gap between the extruder and the build plate, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>t</mi><mo>/</mo><mi>D</mi></mrow></semantics></math></inline-formula>; (iii) the velocity ratio of the moving build plate to the average velocity inside the nozzle, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>V</mi><mo>/</mo><mi>U</mi></mrow></semantics></math></inline-formula>. Numerical results of the deposited strands’ cross-sections demonstrate the effects of controlling parameters on the encapsulation of the core material inside the shell and the shape and size of the strand. Overall we find that the best operating parameters are a diameter ratio of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>d</mi><mo>/</mo><mi>D</mi><mo>=</mo><mn>0.7</mn></mrow></semantics></math></inline-formula>, a normalised gap of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>t</mi><mo>/</mo><mi>D</mi><mo>=</mo><mn>1</mn></mrow></semantics></math></inline-formula>, and a velocity ratio of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>V</mi><mo>/</mo><mi>U</mi><mo>=</mo><mn>1</mn></mrow></semantics></math></inline-formula>.https://www.mdpi.com/2073-4360/13/3/476material extrusionadditive manufacturingcore–shell polymer strandprocessing parametersCFD |
| spellingShingle | Hamid Narei Maryam Fatehifar Ashley Howard Malt John Bissell Mohammad Souri Mohammad Nasr Esfahani Masoud Jabbari Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive Manufacturing Polymers material extrusion additive manufacturing core–shell polymer strand processing parameters CFD |
| title | Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive Manufacturing |
| title_full | Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive Manufacturing |
| title_fullStr | Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive Manufacturing |
| title_full_unstemmed | Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive Manufacturing |
| title_short | Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive Manufacturing |
| title_sort | numerical simulation of a core shell polymer strand in material extrusion additive manufacturing |
| topic | material extrusion additive manufacturing core–shell polymer strand processing parameters CFD |
| url | https://www.mdpi.com/2073-4360/13/3/476 |
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