TY - JOUR

T1 - Mechanical Recyclability of Polypropylene Composites Produced by Material Extrusion-Based Additive Manufacturing

AU - Spörk, Martin

AU - Arbeiter, Florian

AU - Raguz, Ivan

AU - Holzer, Clemens

AU - Gonzales-Gutierrez, Joamin

N1 - Publisher Copyright: © 2019 by the author.

PY - 2019/8/7

Y1 - 2019/8/7

N2 - Due to a lack of long-term experience with burgeoning material extrusion-based additive manufacturing technology, also known as fused filament fabrication (FFF), considerable amounts of expensive material will continue to be wasted until a defect-free 3D-printed component can be finalized. In order to lead this advanced manufacturing technique toward cleaner production and to save costs, this study addresses the ability to remanufacture a wide range of commercially available filaments. Most of them either tend to degrade by chain scission or crosslinking. Only polypropylene (PP)-based filaments appear to be particularly thermally stable and therefore suitable for multiple remanufacturing sequences. As the extrusion step exerts the largest influence on the material in terms of temperature and shear load, this study focused on the morphological, rheological, thermal, processing, tensile, and impact properties of a promising PP composite in the course of multiple consecutive extrusions as well as the impact of additional heat stabilizers. Even after 15 consecutive filament extrusions, the stabilized additively manufactured PP composite revealed an unaltered morphology and therefore the same tensile and impact strength as the initial material. As the viscosity of the material of the 15th extrusion was nearly identical to that of the 1st extrusion sequence, the processability both in terms of extrusion and FFF was outstanding, despite the tremendous amount of shear and thermal stress that was undergone. The present work provides key insights into one possible step toward more sustainable production through FFF.

AB - Due to a lack of long-term experience with burgeoning material extrusion-based additive manufacturing technology, also known as fused filament fabrication (FFF), considerable amounts of expensive material will continue to be wasted until a defect-free 3D-printed component can be finalized. In order to lead this advanced manufacturing technique toward cleaner production and to save costs, this study addresses the ability to remanufacture a wide range of commercially available filaments. Most of them either tend to degrade by chain scission or crosslinking. Only polypropylene (PP)-based filaments appear to be particularly thermally stable and therefore suitable for multiple remanufacturing sequences. As the extrusion step exerts the largest influence on the material in terms of temperature and shear load, this study focused on the morphological, rheological, thermal, processing, tensile, and impact properties of a promising PP composite in the course of multiple consecutive extrusions as well as the impact of additional heat stabilizers. Even after 15 consecutive filament extrusions, the stabilized additively manufactured PP composite revealed an unaltered morphology and therefore the same tensile and impact strength as the initial material. As the viscosity of the material of the 15th extrusion was nearly identical to that of the 1st extrusion sequence, the processability both in terms of extrusion and FFF was outstanding, despite the tremendous amount of shear and thermal stress that was undergone. The present work provides key insights into one possible step toward more sustainable production through FFF.

KW - Fused Filament Fabrication

KW - Recycling

KW - Polypropylene

KW - mineral particles

UR - http://www.scopus.com/inward/record.url?scp=85071151401&partnerID=8YFLogxK

U2 - 10.3390/polym11081318

DO - 10.3390/polym11081318

M3 - Article

VL - 11.2019

JO - Polymers

JF - Polymers

SN - 2073-4360

IS - 8

M1 - 1318

ER -