Fiber reinforcement during 3D printing

• 3D powder printing of fibre-reinforced gypsum for increased green strength.
• Flexural strength could be increased up to 180% by PAN fibre addition.
• Enhanced work of fracture was observed as a typical effect of polymeric fibre-reinforced ceramic matrix.
• Porosity decreased slightly by fibre addition.

Three-dimensional (3D) printing is an attractive rapid prototyping technology for the fabrication of 3D structures by the localized deposition of a reactive binder liquid onto thin powder layers in predominantly technical applications. A practical limitation is often the low green strength of printed samples, which can lead to a collapse of large and fragile structures during removal from the powder bed and the following depowdering procedure. Fibre reinforcement may improve green mechanical properties of printed samples, which was investigated in this study using a range of different short fibres added to a matrix of cellulose-modified gypsum powder. Mechanical testing of printed samples revealed a bending strength increase of 180% and up to 10 times higher work of fracture values compared to non-reinforced printed samples.