owder coatings for metal furnitureare well established in the mar-ket. The advantages of powdercoatings are generally recog-

nized: no VOC, good quality finish andcost effective. As a result, over the lastdecades it has replaced liquid coatingsfor most part in metal furniture. In the early 2000, powder coating forMDF was introduced in the market toallow the industrial wood market to bene-fit from all the advantages of powdercoating: unfortunately, with only moder-ate success. The overlying reason for such limited suc-cess was an underestimation by theindustry what it takes to switch powdercoatings from metal to MDF. Not only thepaint and most MDF types were not suit-able, but also the application lines werenot suitable, as they were still using con-ventional ovens. As a result the boardbecame too hot , which resulted in a ten-dency for cracking especially on theedges. This all gave the first generation ofpowder coatings on MDF a questionablereputation in the industrial wood industry.

In the recent past tremendous progresshas been made to make powder coatingon MDF a reliable alternative to liquidcoatings. Such progress was made pos-sible by building new dedicated powderon MDF lines, using (gas catalytic) IRovens and the development of lower cur-ing (3-5 min 150 °C) powder technologyapplied in two layers. Commercial suc-cess has been demonstrated by theKitchen and Office furniture Industry inBelgium and Germany where powdercoatings have been successfully appliedfor several years (fig. 1). This successhas been further expanded into othermarket segments such as child furniture(fig. 2), shop display, bathroom furnitureand domestic furniture. A large flat packcompany switched from liquid to powderpaint for some of their domestic andbathroom furniture. Building on this initialsuccess, more lines were recently com-missioned to build and to operate.

A recent technology development byDSM not only further reduces the num-bers of layers to one, it is also extreme-

ly fast curing (3 min 120 °C, IR), whilemeeting all the requirements for kitchencabinets and bathroom and office furni-ture. This recent development will fur-ther allow the industrial wood coatingindustry to realize the full set of benefitsof powder coatings on MDF.

SUSTAINABLESustainability is becoming more andmore an topic in the office furnitureindustry, but also in the domestic furni-ture. Depletion of fossil fuels, haz-ardous materials, land use, greenhouse gasses etc. are becoming moreimportant factors in the decision whatmaterial to use. DSM, as a Life Scienceand Performance Material company,believes sustainability is the only way toensure prosperity for the future. DSMhas a dedicated department for calcu-lating Life Cycle Assessments (LCA) inorder to provide information to demon-strate which are most environmentallyfriendly products or processes.For several paint systems (liquid andpowder) for coating MDF the carbon

P

SUSTAINABLE POWDERCOATINGS FOR

WOODEN FURNITUREby Jos Verlaak

NBD Innovation Manager

FOCUSR & D

MATERIALS & TECHNOLOGY

www.worldfurnitureonline.com 39September 2013 - WF

Figure 1.Kitchen. Courtesy of Polylak

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and eco footprint were calculated andcompared. The result was that any pow-der system and in particular our newpowder technology can reduce thefootprints per coated area by almost afactor of 5! (fig. 3).

COST EFFECTIVEAs mentioned previously, powder coat-ings are very cost effective vs any liquidcoatings. This is due to the same rea-son why powder coating has a very lowcarbon and eco footprint: it is very effi-cient to use the paint with little to nowaste generation: up to 95% of thepowder paint can be used. This in con-trast to most liquid coatings where onlyapp 30% of liquid paint ends up on thesubstrate; the rest is evaporated (sol-vent, water) or discarded (overspray,sanding). Further cost reduction isachieved by the very fast throughput;less than 30 min from starting the coat-ing process to finishing it. This allows areduction in Operating Working Capitaland increase in delivery speed.

FREEDOM OF DESIGN Powder coating MDF allows to coat anyshape, from flat material to intricateshapes such as complex routed furni-ture for child furniture, interior separa-tion walls, shop displays etc. Oftensuch shapes would be too complex tocoat with a liquid system as it wouldrequire complicated sanding inbetween layers due to fibre raising. Powder coatings will open up cost

effective design furniture, unheard of ortoo costly to coat with a liquid paint orwith any other finishing technology.

Of course some limitations for powdercoatings on wooden substrate stillapplies especially with respect to typeof substrate; although most MDF typesare suitable, a challenge remains forother boards such as particle board andfor solid wood (except for beech, whichcan be powder coated).Another limitation is still the appearanceof the finish. The paint industry wasable to come up with (ultra fine) tex-tured coated finishes for MDF, whichwas accepted in some market seg-ments currently served by powdercoatings such as (some) kitchen cabi-

net manufacturers and office furniture. DSM and the paint industry are workingto develop smoother powder finishes.However, the orange peel effect is anintrinsic phenomenon for all powdercoatings. For metal this was acceptedby the furniture industry. The future willlearn whether the wood coating indus-try and consumers are willing to accepta light textured or light orange peel forcost effective, excellent wood finish.

DSM and the paint industry is commit-ted to exploit and expand this technolo-gy to other substrates and smoother fin-ishes. The future has started and pow-der coatings on wooden substrates cancreate a revolution in the market forindustrial wood coatings.

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40 WF - September 2013

MATERIALS & TECHNOLOGY

www.worldfurnitureonline.com

Figure 2. Child furniture

Figure 3. Carbon footprint

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