WIELSBEKE, Belgium — Backed by a €20 million investment, Unilin is set to start recycling MDF on an industrial scale at its site in Bazeilles, France. Unilin plans to make this innovative service available to the entire sector via Unilin Technologies.

For the production of its MDF and HDF boards, Unilin Group, a global supplier of panels and building supplies, uses recovered and recycled wood. Until 2021, it was technically impossible to recycle the 100 million cubic feet of medium density fiberboard (MDF) and high density fiberboard (HDF) boards manufactured worldwide each year, but Unilin has developed a steam explosion technology to reclaim the wood fiber from these boards in an economically viable manner and reuse them for the production of high-quality fiberboards on an industrial scale.

According to Geert Coudenys, R&D Director, Unilin Panels, the steam explosion is a process in which biomass is treated with hot steam (180 to 240 °C) under pressure (1 to 3.5 MPa) followed by an explosive decompression of the biomass that results in a rupture of the biomass fibers’ rigid structure. "It sounds quite complicated," Coudenys told Woodworking Network, "but you can compare the process of recycling MDF to the operation of a pressure cooker. First, we moisten the MDF boards with steam. Then the boards are heated and put under very high pressure. Finally, the pressure is reduced, releasing the fibers. 

MDF and HDF containing products, such as laminate flooring, are considered difficult to recycle because of the specific way they are made, Coudenys said. These boards are composed of very fine wood fibers bonded with a urea-formaldehyde adhesive, which makes mechanical recycling methods unsuitable. When mechanical recycling methods (like those used for chipboard) are applied to MDF/HDF, the fibers in these boards are destroyed, preventing them from being reused to create new MDF or HDF products. Instead, these materials have traditionally been incinerated or sent to landfills at the end of their life. To recycle MDF/HDF, a chemical recycling process is needed to preserve the integrity of the wood fibers. However, this process is complex and has been challenging to develop on an industrial scale, requiring significant time and resources to create an efficient and high-quality technology. 

"As a result, recycling these materials has been considered almost impossible for a long time. Until now. Unilin is the first company in the world to develop a technology to recycle MDF/HDF on an industrial scale," he said. "Until now, MDF items such as decorative panels, laminate flooring, and production waste products were simply incinerated at the end of their life cycle. What previously made recycling such products impossible was the glue used to bond the wood fibers. The key to making it possible was therefore to find a way to break down the glue molecules."

 Unilin Panels’ CEO Veronique Hoflack took to the kitchen for the first round of testing, using her pressure cooker. “What we're actually doing is using steam to break apart the glue molecules in cooking vessels,” explains project engineer Stéphane Marthy. “Ultimately, these are agro-industrial machines. To make them suitable for MDF recycling, we put them through a rigorous experimentation process to determine the optimal process parameters.”

From prototype to industrial production
After several years of prototype production, the testing phase finally successfully concluded and the industrial production phase could commence: “We're going to be working with the same kind of machines, but this time they are custom-built for our needs, to handle far higher volumes,” explains Yoann Raucourt, production manager for the Bazeilles site. Currently, Unilin’s Bazeilles plant is already recycling 1500 kilos of MDF an hour, to exponentially increase this rate from September 2025. This is the date the first MDF recycling line should go live.

“MDF recycling enables us to reuse the wood fibers in the product, storing the CO2 in the wood for longer, rather than being incinerated. The aim for the first phase of operation is to store 380,000 tons of additional CO2 per year, equivalent to the annual emissions of 211,000 cars,” explains Julien Boucher, site manager at Bazeilles.

The €20 million investment will fund new industrial plants and equipment, as well as implementing new processes. Subsequently, Unilin will be able to offer MDF panels made from 30% recycled materials, with that proportion undoubtedly set to rise in the future. To achieve this, two recycling lines will have to be created and integrated: the pre-consumer lines, handling waste generated by industrial customers (manufacturers of laminated products, etc.), and the post-consumer lines, processing consumer waste materials recovered at the end of their first life.

Boucher added, "Innovation is in Unilin’s DNA and we are convinced that this MDF recycling technology represents a considerable leap forward for our industry. This is why we are keen to make this technology more widely available, through Unilin Technologies licensing. This will help develop and boost the circular economy of the panels and flooring industry.”