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Hentschel L, Petersmann S, Kynast F, Schäfer U, Holzer C, Gonzalez-Gutierrez J. Influence of the Print Envelope Temperature on the Morphology and Tensile Properties of Thermoplastic Polyolefins Fabricated by Material Extrusion and Material Jetting Additive Manufacturing. Polymers (Basel) 2023; 15:3785. [PMID: 37765639 PMCID: PMC10534743 DOI: 10.3390/polym15183785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/04/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
Additive manufacturing (AM) nowadays has become a supportive method of traditional manufacturing. In particular, the medical and healthcare industry can profit from these developments in terms of personalized design and batches ranging from one to five specimens overall. In terms of polymers, polyolefins are always an interesting topic due to their low prices, inert chemistry, and crystalline structure resulting in preferable mechanical properties. Their semi-crystalline nature has some advantages but are challenging for AM due to their shrinkage and warping, resulting in geometrical inaccuracies or even layer detaching during the process. To tackle these issues, process parameter optimization is vital, with one important parameter to be studied more in detail, the print envelope temperature. It is well known that higher print envelope temperatures lead to better layer adhesion overall, but this investigation focuses on the mechanical properties and resulting morphology of a semi-crystalline thermoplastic polyolefin. Further, two different AM technologies, namely material jetting (ARBURG plastic freeforming-APF) and filament-based material extrusion, were studied and compared in detail. It was shown that higher print envelope temperatures lead to more isotropic behavior based on an evenly distributed morphology but results in geometrical inaccuracies since the material is kept in a molten state during printing. This phenomenon especially could be seen in the stress and strain values at break at high elongations. Furthermore, a different crystal structure can be achieved by setting a specific temperature and printing time, also resulting in peak values of certain mechanical properties. In comparison, better results could be archived by the APF technology in terms of mechanical properties and homogeneous morphology. Nevertheless, real isotropic part behavior could not be managed which was shown by the specimen printed vertically. Hence, a sweet spot between geometrical and mechanical properties still has to be found.
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Affiliation(s)
- Lukas Hentschel
- Polymer Processing, Montanuniversitaet Leoben, 8700 Leoben, Austria
| | - Sandra Petersmann
- Materials Science and Testing of Polymers, Montanuniversitaet Leoben, 8700 Leoben, Austria
| | | | - Ute Schäfer
- Research Unit Experimental Neurotraumatology, Department of Neurosurgery, Medical University of Graz, 8036 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Clemens Holzer
- Polymer Processing, Montanuniversitaet Leoben, 8700 Leoben, Austria
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2
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Heuer A, Rees M, Weidenmann KA, Liebig WV. On the Creation and Optical Microstructure Characterisation of Additively Manufactured Foam Structures (AMF). Polymers (Basel) 2023; 15:3544. [PMID: 37688170 PMCID: PMC10490211 DOI: 10.3390/polym15173544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/09/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
Plastic-based additive manufacturing processes are becoming increasingly popular in the production of structural parts. Based on the idea of lightweight design and the aim of extending the functionality of additive structures, the production of additively manufactured foam structures has emerged as a new field of application. The optical characterisation of these structures is of particular importance for process adjustments and the identification of (unwanted) changes in the foam structure. The degree of foaming and the fineness of a foam structure are of interest at this point. In this context, only the part of a structure dominated by foam pores is considered a foam structure. So far, there are no sophisticated methods for such an optical characterisation. Therefore, in this work, microscope images of manufactured as well as artificially created additively manufactured foam structures were evaluated. On these images, the features porosity, pore size, pore amount and a measure for the textural change were determined in order to obtain information about changes within an additively manufactured foam structure. It is shown that additive structures show changing pore shapes depending on the orientation of the cutting plane, although there are no changes in the foaming behaviour. Therefore, caution is required when identifying changes within the foam structure. It was also found that, owing to the additive process, the total porosity is already set in the slicing process and remains constant even if the degree of foaming of individual tracks is changed. Therefore, the degree of foaming cannot be determined on the basis of the total porosity, but it can be assessed on the basis of the formation of large networks of process-related pores.
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Affiliation(s)
- Anselm Heuer
- Institute for Applied Materials—Materials Science and Engineering (IAM-WK), Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131 Karlsruhe, Germany; (M.R.); (W.V.L.)
| | - Maike Rees
- Institute for Applied Materials—Materials Science and Engineering (IAM-WK), Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131 Karlsruhe, Germany; (M.R.); (W.V.L.)
| | - Kay A. Weidenmann
- Institute of Materials Resource Management (MRM), University of Augsburg, Am Technologiezentrum 8, 86159 Augsburg, Germany;
| | - Wilfried V. Liebig
- Institute for Applied Materials—Materials Science and Engineering (IAM-WK), Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131 Karlsruhe, Germany; (M.R.); (W.V.L.)
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Ahlfeld T, Lode A, Placht AM, Fecht T, Wolfram T, Grom S, Hoess A, Vater C, Bräuer C, Heinemann S, Lauer G, Reinauer F, Gelinsky M. A comparative analysis of 3D printed scaffolds consisting of poly(lactic- co-glycolic) acid and different bioactive mineral fillers: aspects of degradation and cytocompatibility. Biomater Sci 2023; 11:5590-5604. [PMID: 37403758 DOI: 10.1039/d2bm02071h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2023]
Abstract
Their excellent mechanical properties, degradability and suitability for processing by 3D printing technologies make the thermoplastic polylactic acid and its derivatives favourable candidates for biomaterial-based bone regeneration therapies. In this study, we investigated whether bioactive mineral fillers, which are known to promote bone healing based on their dissolution products, can be integrated into a poly(L-lactic-co-glycolic) acid (PLLA-PGA) matrix and how key characteristics of degradation and cytocompatibility are influenced. The polymer powder was mixed with particles of CaCO3, SrCO3, strontium-modified hydroxyapatite (SrHAp) or tricalcium phosphates (α-TCP, β-TCP) in a mass ratio of 90 : 10; the resulting composite materials have been successfully processed into scaffolds by the additive manufacturing method Arburg Plastic Freeforming (APF). Degradation of the composite scaffolds was investigated in terms of dimensional change, bioactivity, ion (calcium, phosphate, strontium) release/uptake and pH development during long-term (70 days) incubation. The mineral fillers influenced the degradation behavior of the scaffolds to varying degrees, with the calcium phosphate phases showing a clear buffer effect and an acceptable dimensional increase. The amount of 10 wt% SrCO3 or SrHAp particles did not appear to be appropriate to release a sufficient amount of strontium ions to exert a biological effect in vitro. Cell culture experiments with the human osteosarcoma cell line SAOS-2 and human dental pulp stem cells (hDPSC) indicated the high cytocompatibility of the composites: For all material groups cell spreading and complete colonization of the scaffolds over the culture period of 14 days as well as an increase of the specific alkaline phosphatase activity, typical for osteogenic differentiation, were observed.
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Affiliation(s)
- Tilman Ahlfeld
- Centre for Translational Bone, Joint and Soft Tissue Research, University Hospital Carl Gustav Carus and Faculty of Medicine, Technische Universität Dresden, Dresden, Germany.
| | - Anja Lode
- Centre for Translational Bone, Joint and Soft Tissue Research, University Hospital Carl Gustav Carus and Faculty of Medicine, Technische Universität Dresden, Dresden, Germany.
| | - Anna-Maria Placht
- Centre for Translational Bone, Joint and Soft Tissue Research, University Hospital Carl Gustav Carus and Faculty of Medicine, Technische Universität Dresden, Dresden, Germany.
| | - Tatjana Fecht
- Karl Leibinger Medizintechnik GmbH & Co. KG (KLS Martin Group), Germany
| | - Tobias Wolfram
- Karl Leibinger Medizintechnik GmbH & Co. KG (KLS Martin Group), Germany
| | - Stefanie Grom
- Karl Leibinger Medizintechnik GmbH & Co. KG (KLS Martin Group), Germany
| | | | - Corina Vater
- Centre for Translational Bone, Joint and Soft Tissue Research, University Hospital Carl Gustav Carus and Faculty of Medicine, Technische Universität Dresden, Dresden, Germany.
| | - Christian Bräuer
- Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus and Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | | | - Günter Lauer
- Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus and Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Frank Reinauer
- Karl Leibinger Medizintechnik GmbH & Co. KG (KLS Martin Group), Germany
| | - Michael Gelinsky
- Centre for Translational Bone, Joint and Soft Tissue Research, University Hospital Carl Gustav Carus and Faculty of Medicine, Technische Universität Dresden, Dresden, Germany.
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Eisele L, Heuer A, Weidenmann KA, Liebig WV. Can Different Parameter Sets Lead to Equivalent Optima between Geometric Accuracy and Mechanical Properties in Arburg Plastic Freeforming? Polymers (Basel) 2023; 15:polym15061516. [PMID: 36987296 PMCID: PMC10054619 DOI: 10.3390/polym15061516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/08/2023] [Accepted: 03/13/2023] [Indexed: 03/30/2023] Open
Abstract
Technological advances have led to the increased use of plastic-based additive manufacturing processes for the production of consumer goods and spare parts. For this reason, the need for the best possible mechanical properties while maintaining geometric accuracy is becoming increasingly important. One of these additive manufacturing processes is the Arburg Plastic Freeforming process, which differs from the widely used Fused Filament Fabrication process in the way that droplets are discharged along a track instead of continuous extruded tracks. As with all other plastic-based additive manufacturing processes, due to the round shape of the tracks, voids occur between the individual tracks during manufacturing, which effects mechanical properties. In contrast to previous work, which mainly focused on how the mechanical properties change with a change in a single printing parameter, this work focused more closely on the interaction of three relevant printing parameters considered as a parameter set. Their influence on the mechanical properties was investigated by tensile tests, the influence on the residual porosity by density measurements and the influence on the geometric accuracy by surface roughness measurements. It was shown that by considering the parameters as a parameter set, states of high density and therefore high mechanical properties while reaching minimal surface roughness can be achieved for significantly more combinations than previously assumed. However, for these states the residual porosity was slightly different. This difference was explained by a parameter-dependent deformation factor of the droplets, which influences the maximal possible degree of filling during manufacturing. For the optimization of arbitrary parameter sets, an analytical model was derived.
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Affiliation(s)
- Lars Eisele
- Institute for Applied Materials-Materials Science and Engineering (IAM-WK), Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131 Karlsruhe, Germany
| | - Anselm Heuer
- Institute for Applied Materials-Materials Science and Engineering (IAM-WK), Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131 Karlsruhe, Germany
| | - Kay A Weidenmann
- Institute of Materials Resource Management (MRM), University of Augsburg, Am Technologiezentrum 8, 86159 Augsburg, Germany
| | - Wilfried V Liebig
- Institute for Applied Materials-Materials Science and Engineering (IAM-WK), Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131 Karlsruhe, Germany
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Chen G, Wang D, Hua W, Wu W, Zhou W, Jin Y, Zheng W. Simulating and Predicting the Part Warping in Fused Deposition Modeling by Thermal-Structural Coupling Analysis. 3D PRINTING AND ADDITIVE MANUFACTURING 2023; 10:70-82. [PMID: 36998792 PMCID: PMC10049873 DOI: 10.1089/3dp.2021.0119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
As the most commonly used additive manufacturing technology, fused deposition modeling (FDM) still faces some technical issues caused by temperature change-induced unsteady thermal stress and warping. These issues can further lead to the deformation of printed parts and even terminate the printing process. In response to these issues, this article established a numerical model of temperature field and thermal stress field for FDM by finite element modeling and "birth-death element" technique to predict the deformation of the part. What makes sense in this process is that the logic of elements sort based on ANSYS Parametric Design Language (APDL) was proposed to sort the meshed elements, which was aimed to perform FDM simulation quickly on the model. In this work, the effects of the sheets shape and infill line directions (ILDs) on the distortion during FDM were simulated and verified. From the analysis of stress field and deformation nephogram, the simulation results indicated that ILD had greater effects on the distortion. Moreover, the sheet warping became most serious when the ILD was aligned with the diagonal of the sheet. The simulation results matched well with the experimental results. Thus, the proposed method in this work can be used to optimize the printing parameters for FDM process.
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Affiliation(s)
- Guoguang Chen
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, Guangzhou, China
- Research Center of Biomass 3D Printing Materials, College of Materials and Energy, South China Agricultural University, Guangzhou, China
| | - Dashuang Wang
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, Guangzhou, China
- Research Center of Biomass 3D Printing Materials, College of Materials and Energy, South China Agricultural University, Guangzhou, China
| | - Weijian Hua
- Mechanical Engineering Department, University of Nevada Reno, Reno, Nevada, USA
| | - Weibin Wu
- College of Engineering, South China Agricultural University, Guangzhou, China
| | - Wuyi Zhou
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, Guangzhou, China
- Research Center of Biomass 3D Printing Materials, College of Materials and Energy, South China Agricultural University, Guangzhou, China
| | - Yifei Jin
- Mechanical Engineering Department, University of Nevada Reno, Reno, Nevada, USA
| | - Wenxu Zheng
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, Guangzhou, China
- Research Center of Biomass 3D Printing Materials, College of Materials and Energy, South China Agricultural University, Guangzhou, China
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Xiang J, Liu Y, Wang J, Wang K, Peng Y, Rao Y, Matadi Boumbimba R. Effect of heat‐treatment on compressive response of
3D
printed continuous carbon fiber reinforced composites under different loading directions. J Appl Polym Sci 2022. [DOI: 10.1002/app.53330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jiangyang Xiang
- Key Laboratory of Traffic Safety on Track of Ministry of Education, School of Traffic & Transportation Engineering Central South University Changsha China
| | - Yisen Liu
- Key Laboratory of Traffic Safety on Track of Ministry of Education, School of Traffic & Transportation Engineering Central South University Changsha China
| | - Jin Wang
- Key Laboratory of Traffic Safety on Track of Ministry of Education, School of Traffic & Transportation Engineering Central South University Changsha China
| | - Kui Wang
- Key Laboratory of Traffic Safety on Track of Ministry of Education, School of Traffic & Transportation Engineering Central South University Changsha China
| | - Yong Peng
- Key Laboratory of Traffic Safety on Track of Ministry of Education, School of Traffic & Transportation Engineering Central South University Changsha China
| | - Yanni Rao
- Key Laboratory of Traffic Safety on Track of Ministry of Education, School of Traffic & Transportation Engineering Central South University Changsha China
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Bayart M, Dubus M, Charlon S, Kerdjoudj H, Baleine N, Benali S, Raquez JM, Soulestin J. Pellet-Based Fused Filament Fabrication (FFF)-Derived Process for the Development of Polylactic Acid/Hydroxyapatite Scaffolds Dedicated to Bone Regeneration. MATERIALS (BASEL, SWITZERLAND) 2022; 15:ma15165615. [PMID: 36013752 PMCID: PMC9415795 DOI: 10.3390/ma15165615] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/29/2022] [Accepted: 08/08/2022] [Indexed: 05/10/2023]
Abstract
Scaffolds can be defined as 3D architectures with specific features (surface properties, porosity, rigidity, biodegradability, etc.) that help cells to attach, proliferate, and to differentiate into specific lineage. For bone regeneration, rather high mechanical properties are required. That is why polylactic acid (PLA) and PLA/hydroxyapatite (HA) scaffolds (10 wt.%) were produced by a peculiar fused filament fabrication (FFF)-derived process. The effect of the addition of HA particles in the scaffolds was investigated in terms of morphology, biological properties, and biodegradation behavior. It was found that the scaffolds were biocompatible and that cells managed to attach and proliferate. Biodegradability was assessed over a 5-month period (according to the ISO 13781-Biodegradability norm) through gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and compression tests. The results revealed that the presence of HA in the scaffolds induced a faster and more complete polymer biodegradation, with a gradual decrease in the molar mass (Mn) and compressive mechanical properties over time. In contrast, the Mn of PLA only decreased during the processing steps to obtain scaffolds (extrusion + 3D-printing) but PLA scaffolds did not degrade during conditioning, which was highlighted by a high retention of the mechanical properties of the scaffolds after conditioning.
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Affiliation(s)
- Marie Bayart
- Centre for Materials and Processes, IMT Nord Europe, Institut Mines-Télécom, University of Lille, F-59000 Lille, France
| | - Marie Dubus
- Biomatériaux et Inflammation en Site Osseux (BIOS) EA 4691 & UFR d’Odontologie, Université de Reims Champagne-Ardenne, F-51100 Reims, France
| | - Sébastien Charlon
- Centre for Materials and Processes, IMT Nord Europe, Institut Mines-Télécom, University of Lille, F-59000 Lille, France
- Correspondence:
| | - Halima Kerdjoudj
- Biomatériaux et Inflammation en Site Osseux (BIOS) EA 4691 & UFR d’Odontologie, Université de Reims Champagne-Ardenne, F-51100 Reims, France
| | - Nicolas Baleine
- Center of Innovation and Research in Materials and Polymers (CIRMAP), Laboratory of Polymeric and Composite Materials, University of Mons (UMons), Place du Parc 20, 7000 Mons, Belgium
| | - Samira Benali
- Center of Innovation and Research in Materials and Polymers (CIRMAP), Laboratory of Polymeric and Composite Materials, University of Mons (UMons), Place du Parc 20, 7000 Mons, Belgium
| | - Jean-Marie Raquez
- Center of Innovation and Research in Materials and Polymers (CIRMAP), Laboratory of Polymeric and Composite Materials, University of Mons (UMons), Place du Parc 20, 7000 Mons, Belgium
| | - Jérémie Soulestin
- Centre for Materials and Processes, IMT Nord Europe, Institut Mines-Télécom, University of Lille, F-59000 Lille, France
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Ficzere P, Lukacs NL, Borbas L. The Investigation of Interlaminar Failures Caused by Production Parameters in Case of Additive Manufactured Polymers. Polymers (Basel) 2021; 13:polym13040556. [PMID: 33668572 PMCID: PMC7918353 DOI: 10.3390/polym13040556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/05/2021] [Accepted: 02/10/2021] [Indexed: 12/12/2022] Open
Abstract
The use of three-dimensional (3D) printing technologies is an ever-growing solution. The product realized in many cases is applicable not only for visual aid, or model, but for tool, or operating element, or as an implant for medical use. For correct calculation, a proper model that is based on the theory of elasticity is necessary. The basis of this kind of model is the knowledge of the exact material properties. The PLA filament has been used to perform this study for matrix material. Our presumption is that the different layers do not fuse completely, and they do not fill up the space available. The failures between the layers and the deposited filaments and the layer arrangement could be the reason for the direction-dependent material properties of the 3D printed objects. Based on our investigation, we can conclude that the increase of the layer thickness and printing speed adversely affect the mechanical properties of the product.
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Affiliation(s)
- Peter Ficzere
- Department of Vehicle Elements and Vehicle-Structure Analysis, Budapest University of Technology and Economics, H-1111 Budapest, Hungary; (N.L.L.); (L.B.)
- Correspondence:
| | - Norbert Laszlo Lukacs
- Department of Vehicle Elements and Vehicle-Structure Analysis, Budapest University of Technology and Economics, H-1111 Budapest, Hungary; (N.L.L.); (L.B.)
| | - Lajos Borbas
- Department of Vehicle Elements and Vehicle-Structure Analysis, Budapest University of Technology and Economics, H-1111 Budapest, Hungary; (N.L.L.); (L.B.)
- Engineering Institute, Edutus University, H-2800 Tatabánya, Hungary
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Ahlinder A, Charlon S, Fuoco T, Soulestin J, Finne-Wistrand A. Minimise thermo-mechanical batch variations when processing medical grade lactide based copolymers in additive manufacturing. Polym Degrad Stab 2020. [DOI: 10.1016/j.polymdegradstab.2020.109372] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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