Shrinkage and Warpage Optimization of Expanded-Perlite-Filled Polypropylene Composites in Extrusion-Based Additive Manufacturing

Martin Spörk, Janak Sapkota, Georg Weingrill, Thomas Fischinger, Florian Arbeiter, Clemens Holzer

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67 Citations (Scopus)


A major challenge in extrusion-based additive manufacturing is the lack of commercially available materials compared to those in well-established processes like injection molding or extrusion. This study aims at expanding the material database by evaluating the feasibility of polypropylene, which is one of the most common and technologically relevant semicrystalline polymers. Expanded-perlite-filled polypropylene and ternary blends with amorphous polyolefins are evaluated to establish an understanding of their processability and their printability. A detailed study on the shrinkage behavior, as well as on the thermal, mechanical, morphological, and warpage properties is performed. It is found that smaller sized fillers result in a tremendous warpage and shrinkage reduction and concurrently improved mechanical properties than compounds filled with bigger sized fillers. Based on the optimal properties profile, a ternary blend that can overcome the shrinkage and warpage of printed parts is suggested.
Original languageEnglish
Article number1700143
Number of pages13
JournalMacromolecular materials and engineering
Issue number10
Publication statusE-pub ahead of print - 4 Jul 2017


  • additive manufacturing
  • fillers
  • microstructure
  • poly(propylene)
  • shrinkage
  • warpage

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