Design And Characterization Of Microfoamed Strands By Continuous 3D Foam Printing

Abstract: We report the design and the results of a novel process that combines 3D printing and foaming to produce microfoamed polymeric structures, from strands to more complex architectures, using physical blowing agents. In the context of polymeric cellular materials, foaming processes, either using physical or chemical blowing agents, are extensively operated in industry to produce pores, yet without a spatial control of the pore positioning. This intrinsic stochastic structuring may introduce imperfections, which reduce the overall mechanical properties of the material; thus, regular (e.g., periodic) structures are more desirable than stochastic ones. 3D printing is another technique to fabricate polymeric cellular materials and it allows to produce cellular materials with empty spaces in precise locations and with a well-defined periodic structure. To this end, very expensive 3D printers are required to achieve micron-resolution pores. Correspondingly, the production time increases dramatically, and becomes a bottleneck to the industrial scale-up. Herein, we present an innovative technique that combines the simplicity of polymer foaming with the precision of 3D printing. The resulting cellular materials have the advantages of both techniques: they have a micron-controlled cell structure and can be printed at reasonable costs and time. The proposed approach is validated using a biobased and compostable polymer for application in biomedical, agriculture and chemical engineering fields. The resulting foamed strands are novel in terms of morphology with a controlled local porosity that opens up to an immense scenario of applications thanks to a possible cost-effective production of hierarchical structures with superior properties (e.g., scaffolds for bioengineering and advanced devices for energy storage or collection).

Biography: Daniele Tammaro received his bachelor’s and master’s degrees in material engineering from the University of Naples Federico II. After his graduation, in 2012, he started a Ph.D. at University of Naples Federico II under the supervision of the Professors E. Di Maio, N. Grizzuti and P.L. Maffettone. During the Ph.D., his research work was focused on polymer science, with main interest on the polymer foaming and process modelling. In 2016, he received a PhD Degree in Materials and Structures Engineering defending a thesis titled “Fundamentals of cell opening in polymers foaming”. After that, he joined Sulzer Chemtech Ltd. as R&D Engineer, leading projects on the development of extrusion foaming process of thermoplastic polymers with innovative applications. Since December 2019, he is a researcher at the Department of Chemical, Materials and Industrial Production Engineering (DICMaPI) at the University of Naples Federico II. His current research interests cover three aspects: study of polymer processing (e.g. foaming), advanced process technologies (e.g. 3D foam printing and 4D printing) and modelling as tool to design multi-properties materials.