Development of thermoplastic vulcanizates based on polypropylene/ethylene propylene diene monomer for prototyping by Fused Filament Fabrication
James Innes, Bana Shriky, Davide Nocita, Glen Thompson, Phil Coates, Ben Whiteside, Adrian Kelly, Michael Hebda
Abstract
This article demonstrates how thermoplastic vulcanizates (TPVs) can be 3D printed by modifying their formulation and the Fused Filament Fabrication (FFF) process. Novel FFF filaments based on polypropylene (PP)/ethylene propylene diene monomer (EPDM) blends were printed and characterized. The development of these TPV filaments allows a broad range of properties by varying the grades of the thermoplastic/rubber phases. Thermoplastic vulcanizates are widely used in the automotive industry, amongst others, and a printable filament could have applications in both prototyping and production of bespoke parts. Given the increasing prominence of TPVs, as replacement for thermoset rubbers, FFF of these materials is considered industrially beneficial. The newly prepared TPVs possessed tensile strength of ∼20–30 MPa and elongation at break ∼700–1100% when measured in the direction of printing. Tensile properties (at 0° and 90° to the printing direction), interlayer adhesion, and Micro-CT were measured and compared with neat PP and PLA.