Wood chips as a new sound-absorbent material

Vinderup Træindustri had all but given up trying to find other ways than burning the large volumes of wood which every year end up as chips on the production hall floors. But what was a pain for the wood industry turned out to be a welcome challenge for six students on DTU’s BEng programmes in Architectural EngineeringManufacturing and Management, and Mechanical Engineering. The challenge ended up winning them first place in DTU’s innovation course and competition Innovation Pilot.

Problem or opportunity?

“Vinderup Træindustri provided the problem with the wood chips as a challenge to the students on the Innovation Pilot course. And with 20 different challenges from 20 different companies, ranging from everything between canteen waste to digitization, we were certain that we could find a good solution to Vinderup Træindustri’s problem,” explains Frederik Aller, who is studying mechanical engineering on DTU’s BEng programme.

That the solution ended up being about acoustics was not least because two members of the group are studying architectural engineering and have specialized in indoor climate and acoustics—and that they were curious about examining the sound damping potential of wood chips.

“Poor room acoustics occur if sound waves are reflected directly by the materials they hit. Porous or soft materials can absorb sound waves, so they are not reflected. This requires a structure that can ‘catch’ the sound waves. We were confident that we could create that type of structure with wood chips,” explains Sandra Nielsen, who is studying architectural engineering.

Glue, cement, and chemicals

However, the group quickly realized that technical and acoustic focus was far from enough to reach the goal of the project: “Vinderup Træindustri sells beautifully crafted laminated wood to companies and individuals, and even though the quality and durability are at a high level, it is equally important that their products function aesthetically in the room they form part of. Otherwise, they simply won’t sell. Therefore, aesthetics also became an important parameter in our development work,” says Signe Ebsen Olling, who is also studying architectural engineering.

After experimenting with various binders like glue, cement, and chemicals for holding the wood chips together and having tested the acoustic properties of the different binders, the group found that glue both created the best acoustic structure and produced the finest surface of the sound-absorbing elements.

“Glue is also a central part of Vinderup Træindustri’s other products and is therefore well-integrated in the company’s production. It will ultimately make it much easier to produce our acoustic panels which we incidentally have chosen to call Arcou,” adds Natacha Charlé Christensen, who is studying manufacturing and management.

The customer as an artist

When the group—which calls themselves Solutions—had found the combination of materials, which both gave the best sound absorption and the best-looking surface, they still had to find a form or an overall expression for the sound-absorbing surfaces. Surprisingly, the solution was not finding a solution. Instead, Solutions let the customer choose the final design.

“We decided to have Arcou produced in several different forms, which the individual customers can combine into their own work of art. In this way, all homes, businesses, venues, etc. create their own unique look using Arcou modules,” explains Signe Ebsen Olling.

Coming into production?

Among the many words of praise which the project received, Vinderup Træindustri’s indication that Arcou was something they wanted to investigate the possibilities of further developing was the highest recognition. At the same time, it is also the best indicator that the many new ideas generated in the project may very well be something we will see in new wood products in the coming years.