Nature's construction principle requires little material and energy. Composite materials such as mussel shells or spider silk are an example of this. These bionics principles can be used to design and manufacture bio-based, sustainable fiber reinforced composites.
Bio-based fiber reinforced composites consist of natural fibers or cellulose fibers embedded in a bio-based matrix. The bio-based components offer properties comparable to those of commonly used glass fiber composites. The German Institutes of Textile and Fiber Research Denkendorf (DITF), Denkendorf/Germany, together with Arburg GmbH + Co KG, Loßberg/Germany, are developing an energy and material-efficient 3D printing process for manufacturing of such lightweight bio-based fiber composites in the " CellLoes-3D-Druck" research project.
In fiber composites, which occur naturally, reinforcing fibers such as collagen or cellulose fibrils are embedded in a matrix of lignin, hemicellulose or collagen. The fiber strands align with the stress patterns. Tissues are formed mostly through solution-based physio-chemical processes that take place at ambient temperature. Similar to nature, new 3D printing processes with continuous fiber reinforcement also allow the deposition of fiber strands in the right place (topology optimization) and in the appropriate direction in accordance with the load. However, natural fibers such as cellulose fibers are sensitive to higher temperatures. Therefore, they cannot be processed in the commonly employed thermoplastic 3D printing process.
The result of the research work is 3D-printed fiber composite components consisting of cellulose continuous fibers embedded in a cellulose-based matrix. Newly developed 3D-printing process enables to manufacture the composites at ambient temperature. This means that - as in nature - the material and component can be produced simultaneously in a single operation at ambient temperature.
The solution-based and energy-efficient manufacturing method developed by the research team can also be used in other composite materials manufacturing processes. It is particularly suitable for processing temperature-sensitive materials that are in high demand, such as natural or cellulose fibers.