2022/05/30
Developing High performance polymers (HPP) for additive manufacturing optimization by fused polymer filament deposition (FDM)
COALIA, Fonds de recherche du Québec – Nature et technologies (FRQNT) (2019-2020)
Objective
Creating high performance filament using high performance polymers (HPP) to provide good interlayer adhesion and mechanical properties that are superior to those of base materials.
Background
3D printing by fused filament deposition (FDM) is a layer-by-layer manufacturing process used to produce parts with a high level of complexity that would normally be unattainable through traditional manufacturing processes like injection moulding. This particular 3D printing process is the most widely used on the market due to its simplicity, low cost and wealth of available materials. It can create prototype and functional parts quickly and at low costs, while avoiding the design and manufacturing steps involved with production tooling.
The challenge
When compared to parts obtained through traditional processes like injection molded, parts printed using FDM technology show inferior and anisotropic mechanical properties (uneven along the printing axis), particularly due to insufficient interlayer adhesion. These parts often reveal inadequate dimensional characteristics due to shrinkage and warping, especially when manufacturing larger parts. These constraints severely restrict the use of FDM for high technology applications, including those associated with the aeronautics sector. A number of strategies have been used to limit these HPP-related effects, many of which show tremendous potential for the aeronautics sector. HPPs (PEI, PPS, PEEK, PSU, PPSU, etc.) are well known in the plastics sector due to their exceptional thermal, thermomechanical and mechanical properties, all of which points to the short-term adoption of these polymeric materials for certain applications, especially those involving metal parts. These materials are not yet widely used in FDM, as they require printing processes and formulations that are adapted to the constraints of additive manufacturing. This could be achieved by the following: 1) Optimizing the FDM process printing parameters for HPPs; 2) Limiting shrinkage by incorporating low linear thermal expansion coefficient fillers into HPPs; 3) Increasing interlayer adhesion by optimizing printing parameters and implementing innovative new technology.