DITF enables the printing of fiber composite components
The lightweight, bio-based fiber composites have drawn inspiration from nature
The German Institutes of Textile and Fiber Research (DITF), together with Arburg GmbH + Co KG, are developing an energy- and material-efficient 3D printing process for the manufacturing of lightweight bio-based fiber composites. To do this, the two organizations have drawn inspiration from nature – using examples such as wood, plant stalks, chitinous shells, bones, tissues (such as tendons and skin), mussel shells, and spider silk.
“We can take advantage of these principles to design and manufacture bio-based, sustainable fiber-reinforced composites, which are currently in high demand. 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,” reads the DITF website.
In fiber composites, reinforcing fibers such as collagen or cellulose fibrils are embedded in a matrix of lignin, hemicellulose, or collagen. Tissues are formed mostly via 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, and in the appropriate direction in accordance with the load. However, natural fibers, such as cellulose fibers, are sensitive to higher temperatures, and therefore cannot be processed in the commonly employed thermoplastic 3D printing process.
The result of the pair’s research work is 3D printed fiber composite components consisting of cellulose continuous fibers embedded in a cellulose-based matrix. Newly developed 3D printing processes enable the manufacturing of the composites at ambient temperature – meaning that, as in nature, the material and component can be produced simultaneously in a single operation.
First, according to the DITF, the cellulose fiber strand is stabilized with a binder for processing in the printer. The specially designed print head transforms the binder into a matrix with which the cellulose continuous fibers are encased. Since the cellulose fibers and the matrix have similar chemical structures, the composite component is particularly stable. The mechanical properties, such as breaking strength, are exceptionally good. The solution-based and energy-efficient manufacturing method developed by the research team can also be used in other composite materials manufacturing processes, and is particularly suitable for processing temperature-sensitive materials that are in high demand, such as natural or cellulose fibers.
The “CellLoes-3D-Druck” research project is funded by the German Federal Ministry of Education and Research as part of the “Biologisierung der Technik” ideas competition.
