Influence of Infill Geometry and Density on the Mechanical Properties of 3D-Printed Polylactic Acid Structure

Additive manufacturing of polymer composites, also known as 3D printing, is one of the progressive technologies in material engineering. It enables the production of parts with complex geometries while optimizing material efficiency. Polylactide (PLA) is a widely used material in additive manufactur...

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Main Authors: Jozef Jaroslav Fekiač, Lucia Kakošová, Michal Krbata, Marcel Kohutiar, Maroš Eckert, Zbynek Studeny, Andrej Dubec
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Journal of Manufacturing and Materials Processing
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Online Access:https://www.mdpi.com/2504-4494/9/4/134
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author Jozef Jaroslav Fekiač
Lucia Kakošová
Michal Krbata
Marcel Kohutiar
Maroš Eckert
Zbynek Studeny
Andrej Dubec
author_facet Jozef Jaroslav Fekiač
Lucia Kakošová
Michal Krbata
Marcel Kohutiar
Maroš Eckert
Zbynek Studeny
Andrej Dubec
author_sort Jozef Jaroslav Fekiač
collection DOAJ
description Additive manufacturing of polymer composites, also known as 3D printing, is one of the progressive technologies in material engineering. It enables the production of parts with complex geometries while optimizing material efficiency. Polylactide (PLA) is a widely used material in additive manufacturing due to its biodegradability and suitable mechanical properties. However, its brittleness and limited thermal stability require further modifications, such as modifying the filler structure or adding reinforcing materials. This paper focuses on analyzing the influence of different filler geometries and densities on the mechanical properties of PLA parts manufactured by the fused filament deposition (FFF) method. Three basic filler structures—cubic, gyroid and rectilinear—were investigated at different density levels from 20%, 40%, 60% and 80%. Experimental tests were performed according to ASTM D638 to determine the strength characteristics of the material. In addition to mechanical tests, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TG) were performed to better understand the influence of the filling geometry on the thermal stability and viscoelastic behavior of the material. Experimental tests according to ASTM D638 showed that higher filling density improves mechanical properties. At 80% filling, the tensile strength reached 21.06 MPa (cubic), 20.53 MPa (gyroid) and 20.84 MPa (linear). The elastic modulus was highest with cubic filling (1414.19 MPa). The yield strength reached 15.59 MPa (cubic), 15.52 MPa (gyroid) and 14.30 MPa (linear).
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spelling doaj-art-008e19bbb2ff46b59aaad7d342d834f32025-08-20T03:13:51ZengMDPI AGJournal of Manufacturing and Materials Processing2504-44942025-04-019413410.3390/jmmp9040134Influence of Infill Geometry and Density on the Mechanical Properties of 3D-Printed Polylactic Acid StructureJozef Jaroslav Fekiač0Lucia Kakošová1Michal Krbata2Marcel Kohutiar3Maroš Eckert4Zbynek Studeny5Andrej Dubec6Faculty of Special Technology, Alexander Dubcek University of Trenčín, 911 06 Trenčín, SlovakiaFaculty of Special Technology, Alexander Dubcek University of Trenčín, 911 06 Trenčín, SlovakiaFaculty of Special Technology, Alexander Dubcek University of Trenčín, 911 06 Trenčín, SlovakiaFaculty of Special Technology, Alexander Dubcek University of Trenčín, 911 06 Trenčín, SlovakiaFaculty of Special Technology, Alexander Dubcek University of Trenčín, 911 06 Trenčín, SlovakiaDepartment of Mechanical Engineering, Faculty of Military Technology, University of Defence, 612 00 Brno, Czech RepublicFaculty of Industrial Technologies in Púchov, Alexander Dubcek University of Trenčín, Ivana Krasku 491/30, 020 01 Púchov, SlovakiaAdditive manufacturing of polymer composites, also known as 3D printing, is one of the progressive technologies in material engineering. It enables the production of parts with complex geometries while optimizing material efficiency. Polylactide (PLA) is a widely used material in additive manufacturing due to its biodegradability and suitable mechanical properties. However, its brittleness and limited thermal stability require further modifications, such as modifying the filler structure or adding reinforcing materials. This paper focuses on analyzing the influence of different filler geometries and densities on the mechanical properties of PLA parts manufactured by the fused filament deposition (FFF) method. Three basic filler structures—cubic, gyroid and rectilinear—were investigated at different density levels from 20%, 40%, 60% and 80%. Experimental tests were performed according to ASTM D638 to determine the strength characteristics of the material. In addition to mechanical tests, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TG) were performed to better understand the influence of the filling geometry on the thermal stability and viscoelastic behavior of the material. Experimental tests according to ASTM D638 showed that higher filling density improves mechanical properties. At 80% filling, the tensile strength reached 21.06 MPa (cubic), 20.53 MPa (gyroid) and 20.84 MPa (linear). The elastic modulus was highest with cubic filling (1414.19 MPa). The yield strength reached 15.59 MPa (cubic), 15.52 MPa (gyroid) and 14.30 MPa (linear).https://www.mdpi.com/2504-4494/9/4/134additive manufacturingpolylactic acid (PLA)infill structure
spellingShingle Jozef Jaroslav Fekiač
Lucia Kakošová
Michal Krbata
Marcel Kohutiar
Maroš Eckert
Zbynek Studeny
Andrej Dubec
Influence of Infill Geometry and Density on the Mechanical Properties of 3D-Printed Polylactic Acid Structure
Journal of Manufacturing and Materials Processing
additive manufacturing
polylactic acid (PLA)
infill structure
title Influence of Infill Geometry and Density on the Mechanical Properties of 3D-Printed Polylactic Acid Structure
title_full Influence of Infill Geometry and Density on the Mechanical Properties of 3D-Printed Polylactic Acid Structure
title_fullStr Influence of Infill Geometry and Density on the Mechanical Properties of 3D-Printed Polylactic Acid Structure
title_full_unstemmed Influence of Infill Geometry and Density on the Mechanical Properties of 3D-Printed Polylactic Acid Structure
title_short Influence of Infill Geometry and Density on the Mechanical Properties of 3D-Printed Polylactic Acid Structure
title_sort influence of infill geometry and density on the mechanical properties of 3d printed polylactic acid structure
topic additive manufacturing
polylactic acid (PLA)
infill structure
url https://www.mdpi.com/2504-4494/9/4/134
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