Title : Improving interlayer bonding and strength in 3D-printed thermoplastics
One of the biggest drawbacks in additive manufacturing of thermoplastic parts using Fused Deposition Modeling (FDM) is the relatively low mechanical properties such as strength and Young’s modulus compared with parts manufactured using conventional methods such as injection moulding. This is mainly due to the weak layer bonding between the consecutive printed layers. Hence, industries such as aerospace and medical sector are reluctant to use FDM for development of parts which require high loading capability. In this work we have used a combination of strategies to enhance the interlayer bonding through changes in printing conditions as well as material composition. For this purpose, IF-WS2 nanoparticles and ZnO tetrapods with adhesion promoting properties were incorporated into high performance Polyether ether ketone (PEEK) in different loading ratios using a twin screw extruder to develop filaments for FDM 3D-printing of samples. IF-WS2 nanoparticles act as solid lubricants which assist polymer chain diffusion and simultaneously improve the mechanical performance of polymer. ZnO tetrapods have adhesion promoting properties which can help with the interlayer bonding in FDM. To evaluate the effectiveness of these approaches, samples were prepared and characterized using SEM, DSC, and mechanical testing. A good distribution of nanoparticles was observed in PEEK based on SEM images. The DSC data showed a small increase in polymer melting point and crystallization upon addition of IF-WS2 and ZnO particles. Based on the tensile testing results, significant improvement in Young’s modulus and Ultimate tensile strength in FDM 3D-printed PEEK samples containing both IF-WS2 and ZnO particles of up to 50%, whereas the improvement was less visible when the additives were added separately. This synergic improvement can be ascribed to the improvement in polymer melt flowability and bonding of polymer chains.
What will audience learn from your presentation?
- I believe that the audience would benefit from this presentation as it discusses additive manufacturing of high performance polymers and some of the challenges surrounding it (i.e. lack of strength and anisotropic properties, lack of repeatability, etc).
- Additive manufacturing (AM) or 3D printing is becoming popular for producing parts from thermoplastic polymers as it can create complex geometries without the need for sophisticated tooling, resulting in cost-effective and sustainable manufacturing.
- High performance thermoplastic polymers, such as polyether ether ketone (PEEK) are becoming increasingly attractive in competition with metals and ceramics for load bearing applications under harsh operating conditions due to their high thermal and chemical stability, exceptional
- A novel approach and a practical solution is offered in this work to overcome some of this issues which would help designers, researchers and industries to use 3D-printing more effectively for producing parts with more uniform properties and higher strength from high performance thermoplastic polymers such as PEEK. These products can be applied in aerospace or medical applications.
- Also, the topic discussed here can be applied in teachings in academia to inform students about the challenges and possible solutions related to processing of high performance polymers, nanocomposites, characterization and additive manufacturing.