Development and structural investigation of 3D printed polymer composites with in-situ foamed core material

Project summary

The aim of the project is to develop and test composite sandwich structures using additive manufacturing techniques, in which a fiber-reinforced shell layer and a porous foam core layer are produced in a single process step by fused filament fabrication 3D printing. The primary objectives of the project are to investigate the effects of fiber length distribution, reinforcing fiber content and the use of recycled fibers in different types of matrix materials, and to explore the effects of short and long fiber reinforcements. In addition, we aim to develop in-situ foamable filaments by investigating the applicability of different chemical and physical blowing agents, with a particular focus on thermally expandable microsphere-filled biopolymer filaments. The research will analyse the influence of printing parameters such as temperature, printing speed and layer height on the foaming dynamics and the cell structural properties (cell size distribution, cell density) obtained. By optimising the printing parameters, it will be possible to produce cell structures that contribute to improving the mechanical properties of the foam and enhancing the energy absorption capacity. Based on this understanding, it will be possible to produce functional structures with controlled varying porosity along the cross-section, which not only provide high energy absorption capacity, but also modify the other mechanical properties of the structure (e.g. stiffness, strength) in a favourable direction. This allows the development of unique, tailor-made solutions to meet different industrial needs, for example in the automotive industry, where lightweight but strong structures are important, in medical technology, where porous structures are often used as bone substitutes, or in sports equipment, where the main goal is to increase the shock absorbing efficiency of protective equipment. The use of recycled fibers and the reduction in weight through targeted porosity and the associated improvement in functionality also contribute to reducing the environmental footprint.

Project results

Project-related publications

1. 
   Tóth Cs., Lukács N. L., Kovács N. K.: The role of the fiber–matrix interface in the tensile properties of short fiber–reinforced 3D-printed polylactic acid composites. Polymer Composites, , 14 (2024) https://doi.org/10.1002/pc.28720 IF=4.8 Q1