A new product and process is changing the perception of 3D printing and expanding design possibilities for making things out of wood with no waste.

Called Forust, the new product was developed by a 3D printing technology company based in Boston called Desktop Metal. It uses sawdust and adhesive in a computer-driven process that can create wood parts without waste in design configurations that are difficult to impossible to achieve with conventional subtractive woodworking procedures.

One of the co-inventors of the process recently talked at length with us about the product, process, and possibilities of this new technology. Ronald Rael is a professor of architecture at the U.C. Berkeley College of Environmental Design. He says the driving force behind development of Forust has to do with creating a more sustainable wood manufacturing model, but it also can solve a host of wood manufacturing challenges from historic restorations to creating luxury wood products to whole new products that have yet to be dreamed up.

About the process
Rael says the process used to create Forust is very different from the common conception of 3D printing.
“Maybe many of your audience members have heard about 3D printing and think about plastic squirted through a little nozzle, and sometimes there’s an introduction of different kinds of materials like metals or woods with that plastic, but our process is very, very different,” Rael said. “We use reused and upcycled sawdust, so we’re taking the sawdust powder and we’re spraying it with a biodegradable and non-toxic adhesive to stick it together, so we’re reconstituting sawdust to create larger wood products.”

Rael says the process used is actually not new technology, but applying it to create wood products is a new application that expands the potential of an older 3D printing process.

“The technology is a really interesting technology, and it’s one of the oldest forms of 3D printing.” Rael said. “It’s been around over 30 years. It something that just hasn’t used many different kinds of material technologies. One of our innovations is that we’ve been able to introduce a new type of material to the system.”

What can it do?
Rael paints a picture of using this technology to create “almost anything,” but it does have particular applications and design possibilities.

“It’s really up to designers’ imaginations, but we can imagine things like architectural products for interiors, any kind of wall claddings, surfacing, almost anything you can imagine, luxury interiors, consumer goods, furniture,” he said. “We’re starting from the particle of sawdust, and we’re able to imagine if you grow that particle, those particles of sawdust and adhere them together to make any shape, you can really make anything that you might imagine.”

One application includes reproducing historic mouldings without the need to create moulding knife profiles or machine any more than the exact amount of material you need.

“In a historic renovation, for example, you might have a particular moulding, and it might be rotted. So, there might be a very small section or something. So, you have to go through all this custom tooling to replicate it, and that can be very expensive,” Rael explained. “But today, you can actually take a 3D scan with your telephone, with your iPhone, your smartphone, and you’ll have an instant CAD file that you can deliver to us, and it’s ready to print.”

New kind of grain
The process creates its own kind of grain in the printed wood parts. A statement on the Forust website describes the result as “3D printed, digitally rematerialized wood, with grain that flows across the entire part and can be sanded and refinished.”

Rael describes the process in more detail. “Because additive manufacturing is layer by layer in the same way trees build up layers as they grow, there is a certain directionality to the material,” he said. “Those layers in some cases can emulate or appear to be like wood grain as if the product actually grew just like in the same way a tree grew. But we can do some very special things layer by layer as well, like we can introduce different colors into the layers.”

3D printing technology even can be used not only to print the wood particles, but also the process can print images onto or even into the wood. “If you wanted to emulate a wood grain of any kind, you actually could do that within the wood structure,” said Rael.

This also presents finishing and pre-finishing opportunities, he said. Hyper localized color, even images could be applied within the wood product as part of the process. Rael compared it to applying a stain with a fine paint brush not only on the outside of a wood product, but inside, through the layers of grain or within the layers of grain themselves.

“What we’ve been doing so far is emulating different kinds of wood grains, but it could be actually anything or any image,” Rael said. “That opens it up to new kinds of possibilities of what applying finishing to a wood product might look like, and that’s yet to be discovered.”

Compared to natural wood
Just as woodworkers select particular wood species for their specific properties to best match them to a particular application, one naturally would want to know how Forust compares in strength and other characteristics to natural wood.

“(Forust) is an isotropic material and it has strength similar to if not greater in some cases than wood,” Rael said. “We can make it very strong. It has structural capabilities.”

He said they are limited by capabilities of existing machinery to print Forust parts. For example, don’t think of Forust as being the go-to product for large structural beams at this time.

“The beauty of it is that most wood products if they are assembled, are made of smaller wood parts, so we can manufacture many parts to produce larger structural items,” he said. “I don’t want to exactly say it’s like laminated timber, but in a way it’s laminated at the microscopic level. We can also laminate parts, but those parts don’t have to be flat like laminated wood products. They can be many different shapes and they can be joined together and connected and glued.”

One advantage Forust has over natural wood is greater dimensional stability that can even be enhanced by coatings applied during the printing process and after the part is printed.

“What’s interesting about that is that it’s infused into the layers, so it’s not just an exterior surface coating, it’s actually infused several layers in,” he said. “Rather than being sprayed on or painted as in a piece of furniture, a table, this is embedded much more deeply within the wood particles.”

Additive vs. subtractive
Understanding the potential of this new technology has a lot to do with understanding the differences between additive and subtractive manufacturing.

In traditional woodworking, the process is fundamentally subtractive, staring with trees, removing material to make logs, removing more material to make lumber, and continuing the subtractive process, removing even more material to dimension parts, create joinery, and shape parts for both decorative and mechanical purposes. In contrast, additive processes start from nothing and add material to get the final result.

“Because we’re growing it additively, we can make shapes and forms that could not be made possible with other forms of tooling,” Rael said. “That opens it up to new kinds of possibilities, maybe even products that are yet to be imagined.”

But it also requires thinking differently. Woodworkers will have to put aside their subtractive mindset to think additively to reap the full benefits of additive processes.

“I think in a certain way one has to abandon first what it means to subtract from wood and just to allow oneself to imagine what might be possible,” Rael explains. “For example, if you wanted to make a very large sphere or void inside a block of wood with a very small hole coming into it, I can’t imagine a tool that would do that very easily or if at all. But that could be absolutely possible with additive manufacturing.”

Rael thinks woodworkers’ understanding of manufacturing processes is tool dependent. “I think woodworkers or craftsmen begin to think based on the tool. They might think in terms of what does a chisel do or what does a bandsaw do or what does a CNC mill do,” he explains. “And craftspeople begin to think through those tools. I think one thing we have to recognize is this is a very new kind of tool, and that’s simply what it is. The tool allows us to produce new kinds of objects.”

Making parts from waste
Sustainability is clearly behind the development of Forust. Even the name of the product derives from that goal.

“We decided to go with Forust with U-S because we believe maybe we could preserve the forest for us, the planet and for the future,” he said. Rael emphasizes that Forust solves a major challenge in woodworking, dealing with large quantities of waste.

“If you wanted to make a hole in wood, you’d be removing all that wood, and you’d be left with a pile of wood dust, of sawdust, of shavings. We’re starting from there,” he explains. “So, when we make something, we’re not left with a pile of wood dust. We’re only left with the product, and that residual waste can be recycled back into our system and we can continue to make objects that way.”

Efficiency
Rael believes additive processes in general and the Forust product in particular add efficiencies to woodworking. Initially woodworkers could be attracted to a product that can be made without waste as an efficiency in itself, but Rael says the concept of efficiency should be broader.

“The efficiency of a product might be that it could be much more light weight or it could be a shell or it could be a three-dimensional object that would be very difficult to make that works with sound attenuation. I think the possibilities are endless,” he said. “A heavy piece of wood could be a light piece of wood. It can be perforated in ways that aren’t simply drilled through but in complex ways that are much more three-dimensional. So, the kinds of products that could be produced I think are yet to be discovered.”

Service bureau model
While many woodworkers will want to ask about buying machines to 3D print Forust products, the company is initially working from a service bureau model. That means wood manufacturers will send scans or digital files to Desktop Metal to have them printed in Forust material. The company wants to make software tool sets available so customers can work through additive design to achieve the parts they need. Rael emphasizes woodworkers need to approach all additive processes as a new tool for their shops.

“If we think about the moment that a particular woodworking tool was created like the CNC mill or the chisel or whatever, it expanded the possibilities of making,” he said. “We’re just going to expand the possibilities of making. We could think about traditional wood processes like wood restoration for example might play a role, but we can think about the future of wood products and those are yet to be discovered and those are going to be the most exciting discoveries that happen.” 

You can listen to the full interview with Ronald Rael below.