Project R-14223

Understanding droplet generation and layer formation using Ultrasonic Spray Coating for the roughness reduction and application of functional coatings on Additive Manufactured free-form parts (Research)

A major problem in additive manufacturing is the post-treatment, required on all 3D-printed objects to reduce surface roughness. In most cases this post-treatment is performed by labour-intensive, subtractive techniques such as grinding or laser ablation. More recent post-treatment techniques, such as spray or laser coating, add a final, smooth layer, that is, however, too thick for a real breakthrough. The focus of this project will therefore be on the fundamental understanding of the application of novel, polymer/nanoparticle based inks through Ultrasonic Spray Coating to deposit thin and smooth coatings on Selective Laser Sintered parts, with enhanced functionality. For this, the fundamental understanding of structure-property relations between the polymer/nano-particle suspension rheology, the flow fields encountered in Ultrasonic Spray Coating and the plasma treatment related energies of the 3D-printed surfaces will be aimed for. Apart from creating smooth surfaces, the layers will also have extra functionalities being super-hydrophobicity or scratch resistance. This will be achieved by diffusion of FP-POSS nanoparticles to the surface of PMMA coatings. Only the combined fundamental scientific knowledge on rheology and formulated ink properties, with this ultrasonic spray coating technique, and the printing and pre-treatment of the substrates, will lead to superior 3Dprinted parts that reduces post-treatment time, labour and material cost for the AM field.

01 November 2023 - 07 March 2024