Many people are concerned about the environmental impact of additive manufacturing and are trying to find more sustainable ways of 3D printing. This often involves finding new materials that are more environmentally friendly than, for example, plastic. In a paper entitled “Control of Process Settings for Large-Scale Additive Manufacturing with Sustainable Natural Composites,”A team of researchers described the additive manufacturing system they developed for 3D printing of large objects using natural biological composites.
According to the researchers,composites made of natural materials with good mechanical properties are limited in use because they are often mixed with plastics or dangerous solvents,and for the most part their use has only been demonstrated on a smaller scale. Since most natural biological composites are water-based, they face a range of challenges, as the removal of moisture leads to changes in structure and size as they dry and harden.
In the study, researchers used a cellulose - chitin material that is both recycled and biodegradable.In its dry state, its mechanical properties are similar to that of Rigid Polyurethane Foam.It is flexible and thixotropic in the wet state, which means it is viscous in the static state, but flows under the pressure of the extruder.As it dries out, it contracts anisotropic.