TY - JOUR

T1 - Optimization of Mechanical Properties of Glass-Spheres-Filled Polypropylene Composites for Extrusion-Based Additive Manufacturing

AU - Spörk, Martin

AU - Savandaiah, Chethan

AU - Arbeiter, Florian

AU - Sapkota, Janak

AU - Holzer, Clemens

PY - 2017/12/26

Y1 - 2017/12/26

N2 - Polypropylene (PP) parts produced by extrusion-basedadditive manufacturing (EB-AM) suffer from warpageissues due to their high degree of crystallinity and ori-entations introduced during printing. These issues canbe overcome by the addition of spherical fillers. How-ever, the low aspect ratio of the filler and high fillingdegrees necessary for preventing warpage downgradethe mechanical properties, especially the toughness.This study aims at optimizing a PP-compound contain-ing spherical glass microspheres for the application inEB-AM by maximizing the matrix–filler compatibilityand therefore the printability, tensile properties andtoughness, while still counteracting dimensional inac-curacies. A detailed study on the tensile, fracture, ther-mal, rheological, and impact properties of variouscompounds containing different glass types was con-ducted. It was shown that for EB-AM applications, PPcompounds based on borosilicate glass spheres out-perform compounds filled with the conventionally usedinorganic soda lime glass. The proposed optimizedcomposite exhibits an exceptional interfacial adhesionbetween the microspheres and the matrix and a homo-geneous filler distribution. It offers an improved pro-cessability and tensile properties up to the yield pointcomparable to those of neat PP. In a concludingimpact test on printed composites, the optimized sys-tem exhibited impact energies 80% higher than com-pounds containing the conventionally used glass.

AB - Polypropylene (PP) parts produced by extrusion-basedadditive manufacturing (EB-AM) suffer from warpageissues due to their high degree of crystallinity and ori-entations introduced during printing. These issues canbe overcome by the addition of spherical fillers. How-ever, the low aspect ratio of the filler and high fillingdegrees necessary for preventing warpage downgradethe mechanical properties, especially the toughness.This study aims at optimizing a PP-compound contain-ing spherical glass microspheres for the application inEB-AM by maximizing the matrix–filler compatibilityand therefore the printability, tensile properties andtoughness, while still counteracting dimensional inac-curacies. A detailed study on the tensile, fracture, ther-mal, rheological, and impact properties of variouscompounds containing different glass types was con-ducted. It was shown that for EB-AM applications, PPcompounds based on borosilicate glass spheres out-perform compounds filled with the conventionally usedinorganic soda lime glass. The proposed optimizedcomposite exhibits an exceptional interfacial adhesionbetween the microspheres and the matrix and a homo-geneous filler distribution. It offers an improved pro-cessability and tensile properties up to the yield pointcomparable to those of neat PP. In a concludingimpact test on printed composites, the optimized sys-tem exhibited impact energies 80% higher than com-pounds containing the conventionally used glass.

M3 - Article

VL - 83

SP - 1

EP - 14

JO - Polymer Composites

JF - Polymer Composites

SN - 0272-8397

ER -