Zero emission board ambitions

Belgium-based Emulco NV has been busy on the research and testing front in the field of bio-wax emulsions with the introduction of its AquaVeg bio-emulsion into the panel board industry.

The panel board industry heard about the product in a joint presentation between Emulco and bio-based adhesives producer Sestec at the recent International Panel Products Symposium in Wales (organised by the BioComposites Centre).

The emulsion specialist told delegates it had succeeded in combining its AquaVeg water-based bio-emulsion with formaldehyde-free bio-based binders to produce zero-emission panel boards. The findings created significant interest.

Now that lab and industry tests are finalised, Emulco has started the commercialisation of its emulsion towards environmentally conscious producers of wood panels in order to bring the new panels to the market.

Several negotiations are currently ongoing, which means that the zero-emission wood panels might be available on the market in the mid to long term.

“Construction companies and developers in the ever-growing segment of eco-buildings and the health infrastructure sector are natural partners for the use of the new biobased panels,” said Emulco.

Besides traditional panel board products, Emulco’s AquaVeg emulsions have also been successfully introduced as a top coating for LVL (laminated veneer lumber) and CLT (cross-laminated timber) and other construction materials.

Emulco says both MDF and PB panels treated with Emulco’s and Sestec’s products passed lab and production tests with “flying colours”.

Particleboards and MDF boards treated with the bio-based solution reached comparable or even better scores to panels treated with mineral wax emulsions in terms of internal bond strength (IB), modulus of rupture (MOR) and water resistance.

All panels produced with AquaVeg emulsion have demonstrated equal or better performances in thickness swelling and water absorption compared to mineral wax emulsions.

Since neither the bio-based adhesive nor AquaVeg emulsion contain formaldehyde, the only remaining formaldehyde emissions are the ones produced by the wood itself.

Emulco’s AquaVeg is a family of waterbased emulsions made from vegetable waxes. They are a sustainable alternative for mineral wax emulsions, because they are bio-degradable and with zero VOC emissions.

“The possibility to treat MDF and PB boards with a formaldehyde-free combination of our AquaVeg bio-emulsions and bio binders is a great accomplishment of Emulco’s and Sestec’s R&D capabilities,” said Jean Vanhoebost, CEO of Emulco.

“The market opportunities are huge, because eco-building is quickly becoming a leading trend in the construction sector.

We are proud to contribute to a more sustainable wood and construction sector.”

EMULCO AND AQUAVEG RESEARCH

Emulco specialises in high-end and complex emulsions such as EPDM, PIB and bioemulsions for the wood, food packaging, construction, cosmetics, chemical and textile industries. Headquartered in Ghent, Emulco says it serves customers all over the world.

The IPPS conference in Wales last October saw a presentation on ‘Combining bio-based resins with bio-based wax emulsions to produce zero emission panels’, with Emulco’s Rob Van Hooghten sharing details of the research.

One of the main principles behind the research was that, although conventional paraffin wax emulsions are effective and available at a relatively low cost, they are by definition not sustainable.

In the research, Emulco’s Aquaveg biobased wax emulsions were based on partially hydrogenated vegetable oils – rapeseed, palm, coconut oils etc. The resins used from SESTEC - W508 (for PB production) and W67G (for MDF) covered by patent application – were based on natural renewable polymers – plant proteins. The attractiveness of this material is due to a variety of functional groups which after modification ensure a good wood bonding.

All PB and MDF samples were prepared in the SESTEC Polska Sp laboratory.

The Aquaveg bioemulsions showed characteristics of intrinsic water repelling properties, as well as a similar melting point and hardness as paraffin waxes. Furthermore, they are said to be non-toxic, VOC-free and have a high melting point, implying that almost no evaporation of the wax occurs during pressing of the panels.

In the testing, particle size distribution of the bio-wax emulsions is measured after several treatments: shelf-life testing, thermal cycling between room temperature and 50OC and accelerated aging in a centrifuge.

Testing showed particle size distribution was not altered after the treatments. The distribution was monomodal with a mean of around 400-500mm.

Four emulsion types were shown to be the most suited for PB and MDF production. The key difference between the emulsions is the wax blend and the surfactant type. When the biosurfactant was used to stabilise the emulsion, a biocontent and a biocarbon content of almost 100% was reached.

The low viscosity of the emulsions in combination with the low droplet size is expected to give a good spreading of the bio-wax on the chips and fibres.

All test boards were produced at a target density of 650kg/m3 for PB and 820kg/m3 for MDF.

The addition of a hydrophobing emulsion to the PB significantly increased the resistance to water, with both the swelling and water absorption lower compared to an emulsion-free panel.

For the conditions under study, one of the Aquaveg emulsions reduces both by approximately 25% compared to reference fossil emulsion. This improvement is said to be so meaningful that researchers will expand their tests and activities.

Mr van Hooghten shared how combining bio-based resins with bio-based wax emulsions could produce zero emission panels.

MDF and PB samples produced with the natural products achieved results comparable to, or better than the reference paraffin wax emulsion panel. The panels met the IB and MOR standards for class P2 and MDF.

Because SESTEC resins and Emulco bioemulsions contain natural, environmentally-friendly ingredients, it makes them safe for both employees on the production line and consumers.

Test panels were also assessed for formaldehyde emissions, with reported results being steady state values after five days in the testing chamber on a total testing period of 12 days.

The results show the formaldehyde emissions of the bio panels were very low, even below the European and Japanese emission limits. The PB sample registered 0.008mg/m3 and the MDF 0.032mg/m3, compared to the Europe E1 standard (0.124mg/m3) and Japan’s standard (0.034mg/m3). It is to be noted that the new commission regulation (EU) 2023/1464 of July 14, 2023, sets a new maximum limit of 0.062mg/m3.

The emission of the PB board tested is particularly low, considering no surface treatment (eg lamination) or formaldehyde scavenger is added.

This research and the start of commercialisation of the Aquaveg emulsion will be interesting to watch as the field of environmentally-friendly low-carbon building and furniture products is currently of intense interest and scrutiny.