3D Printing Real Wood With Just Cellulose and Lignin

Though the elements of wooden – cellulose and lignin – are exceedingly low-cost and plentiful, combining these right into a wood-like construction just isn’t simple, regardless of many makes an attempt to make these elements in some way self-assemble. A latest try by [MD Shajedul Hoque Thakur] and colleagues as published in Science Advances now might have come closest to 3D printing literal wooden utilizing cellulose and lignin ink, utilizing direct ink writing (DIW) as additive manufacturing technique.

This water-based ink was created by mixing TOCN (tempo-oxidized cellulose nanofiber), a ten.6 wt % aqueous CNC (cellulose nanocrystals) and lignin in a 15:142:10 ratio, giving it roughly the viscosity of clay. The aim of getting each TOCNs and CNCs is to duplicate the crystalline and amorphous cellulose parts of wood-based cellulose.

This ink was printed from a syringe head (SDS-60) put in in a Hyrel 3D Engine HR 3D printer. This printer is very similar to your common FDM printer, simply focusing on bioprinting and a variety of heads to print and deal with varied attachments in a laboratory setting. The ink was extruded into particular shapes that have been both freeze dried to eliminate the liquid part, or moreover additionally heated (at 180°C), with a 3rd set of samples put right into a scorching press. These further steps appear to advertise the binding of the lignin and create a extra sturdy consequence.

The produced samples have been in contrast towards the pure hardwood (balsa wooden) which its components have been derived from. Not in contrast to with FDM printing, the heating and strain appears to advertise the annealing between the completely different layers, which themselves are considerably much like the expansion patterns present in pure wooden. Successfully, the extra the samples have been pressed in additional instructions, the higher their properties, but lacking from the printed wooden are the lengthy fibers that naturally happen through the development course of.

Though promising, the researchers be aware that the concerned steps of freeze drying and hot-press are power intensive, to not point out cumbersome. These findings do increase the prospect of additional developments of this primary ink formulation and post-processing strategies which might making it extra accessible and environment friendly. Maybe someday DIW wooden printing will develop into as a lot as a secure of interest rooms and manufacturing services as FDM, SLS and SLA printing at the moment.