How do we produce sawdust additively?

One man’s trash is another man’s treasure, and this old adage proves true in the recycling industry. From food and packaging to the construction industry, waste is everywhere – the good news is that it can be transformed into objects and materials that we can reuse.

For example, sawdust: most companies consider it waste, President comes with a different approach. In May, the startup launched a technology that uses recycled sawdust and other wood industry byproducts to make 3D-printed objects that appear to be made from traditional wood. Winner in the Materials category of the 2021 Fast Company Design Innovation Awards, Forust can create virtually anything, from household items to intricate architectural details. It can also reproduce any type of wood, from ash to mahogany, making it a valid and long-lasting substitute for traditional wood.

How do we produce sawdust additively?

“We use so much wood in architecture,” says Virginia San Fratello, chair of the design department at San Jose State University and co-founder of Forust. “How could we create a 3D printed product that looks like it’s made of linen but is actually made of this material that would otherwise be destined for landfill?” Although sawdust is biodegradable, when it decomposes in large quantities in landfills, it releases high concentrations of lignin and fatty acids, which then contaminate the water supply.

Forust is a subsidiary of Desktop Metal, a company that has been 3D printing metal since 2015. Therefore, they replicated the 3D printing process used on metal for wood. Thin layers of sawdust are laid out on the print bed of printers modified to print with wood products. San Fratello says the printed products are very delicate, so they are treated with a non-toxic binder such as lignin (a natural polymer found in the cell walls of woody plants) to make the material more durable. For an object the size of a small vase, the process takes about two hours and is finished with traditional wood treatments such as sanding, staining or varnishing.

To demonstrate the approach, Forust teamed up with Yves Béhar’s Fuseproject and they designed a collection of household items, including a pear-shaped bowl, bowl, basket and tray, all using Forust technology. “We developed an algorithm that establishes the pattern on each layer as it is 3D printed,” says San Fratello, “and then builds a natural-looking faux wood bowl.”

The team also experimented with color, but the biggest challenge remains volume. Because of the limited size of the print bed, objects larger than 8 inches must be made in parts, but San Fratello says work is nearing completion on a robotic arm that will facilitate the production of much larger objects. Forust is also working to make 3D wood strong enough to be used in buildings. In the not-too-distant future, we may see 3D printed structural columns with ornate, intricate details that could otherwise only be sculpted by hand. “We could 3D print, in a few days, an object whose sculpture, for example, would take hundreds of hours,” says San Fratello.

Soon the possibilities will be endless, from door handles to high-end vehicle wood panels to furniture. Currently, anyone can generate a 3D model and Forust can print it, as long as the final product is less than 8 inches. But the startup is also developing in-house products, including 3D-printed tiles, furniture and even lighting fixtures in collaboration with a London-based designer. “Everywhere you see wood, we could use 3D printed sawdust,” says San Fratello.

While this may seem like a threat to the traditional way of working with wood, San Fratello insists that the two approaches can coexist. “I don’t think 3D printers and robots will take over manufacturing,” he says. Like a hammer or a saw, the 3D printer will be just one of the tools in the toolbox. This is the future.”