A New System Uses Sawdust to Print Wooden Objects (opens in new tab)

Thank you for doing their job right. To be fair, desktopmetal.com is at least being linked below, but after clicking it I simply felt mislead, consequentially closing it again.

Fibrous composite materials can be significantly stronger than the source materials themselves. The binding agent forms a matrix which holds fibers together and so can be strong in localized fashion to hold fibers. This strength would usually result in the binding agent becoming brittle as a bulk material.

The overall strength comes from the combination of the two, with increased fracturing/tearing resistance due multiple independent fibers. Tears have a harder time propagating when each fiber needs to be fractured. Materials "fail" by cracks or fractures forming. In homogeneous materials the energy to continue a crack is generally much lower than continuing a tear. Sort of like static vs dynamic friction. Once started a crack will continue with a lot less effort leading to lower material strength. Fibers with a binding agent help prevent this effect.

A fantastic example of this effect is Pykrete which is just sawdust mixed into water before freezing. It becomes stronger than concrete (in tensile strength): https://en.wikipedia.org/wiki/Pykrete

Here's a link to a general material science intro on composites if you're curious: https://in.bgu.ac.il/engn/mater/Documents/LaboratoryBriefing...