Designing 3D printable polypropylene: Material and process optimisation through rheology

• Published in: Additive manufacturing 2021-04, Vol.40, p.101944, Article 101944
• Main Authors: Bertolino, M., Battegazzore, D., Arrigo, R., Frache, A.
• Format: Article
• Language: English
• Subjects: 3D Filament optimisation; Fused deposition modelling (FDM); Polypropylene; Rheology; Talc
• ISSN: 2214-8604; 2214-7810
• DOI: 10.1016/j.addma.2021.101944

A polypropylene-based material has been formulated to be suitable for fused deposition modelling (FDM). In fact, the high volumetric shrinkage and the rheological behaviour are main problems whereby polypropylene (PP) is not commonly used as a 3D printing filament. Experimental results have evidenced how material modifications have a strong impact on rheological behaviour, providing critical features that permit and improve material printability. An optimised 20 wt% talc filled heterophasic PP copolymer has been developed. The peculiar properties of the materials have been assessed by thermal characterisation and rheological analysis. Several process parameters (extrusion temperature, screw speed, cooling conditions) have been evaluated in order to obtain a proper filament. Finally, a model part has been printed using different settings to check printing quality by morphological analysis. [Display omitted] •Rheology has a key role to determine a polymer 3D printability.•Yield stress behaviour and strong shear thinning allow PP manufacturing with FDM.•Talc filled heterophasic PP copolymer is an excellent solution.•Suitable filament optimising surface roughness and ovality.•3D quality enhancement balancing printing temperature and speed.