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Modified wood products

Wood modification is becoming an ever-more popular method of enhancing the natural properties of timber. Recent years have seen an increase in products
emerging on the market with the majority coming from Northern Europe.

One of the main drivers for product development in terms of wood modification has been to increase the decay resistance of those timbers whose durability is naturally low. This potentially allows low-grade timbers to be used in situations when, previously, they would not have been suitable.

These timbers usually require preservative treatment to increase their lifespan; however wood modification can do this while also providing a variety of other beneficial changes, such as improved dimensional stability and resistance to insects.

The process of wood modification involves applying a substance to the wood resulting in a permanent change in the characteristics of the material. Some of these processes have been used for centuries, yet the scaling up of wood modification has only really happened within the last decade.

Wood modification can be split into three main categories: thermal; chemical; or impregnation.

Heat treatment is the most common form of timber modification and has been used for more than 50 years. Wood is heated to temperatures of more than 200°C without the presence of oxygen, causing the chemical makeup of the wood to alter. However, this form of modification does affect the strength of the wood, making it unsuitable for structural applications.

The use of chemical modification techniques is becoming increasingly popular, with companies such as Kebony and Accoya now using it as their sole method for wood modification.

Accoya uses a chemical process called acetylation. Wood is made up of free hydroxyls; these hydroxyls absorb and release water depending on the climatic conditions to which the wood is exposed.

Acetylation transforms the free hydroxyls in the wood into acetyl groups, reducing the wood’s ability to absorb water, thereby making it more dimensionally stable and more durable. These acetyl groups are already present in all wood species - as a result, the manufacturing process of timber that is modified using this method adds nothing to the wood that is not naturally present.

Acetylation has been shown to improve the following qualities of wood: durability; resistance to swelling and shrinkage; hardness; and UV resistance.

Furfurylation combines both an impregnation and a chemical process. Furfuryl alcohol is impregnated into the wood and polymerised. This is the process
of modification used by Kebony. The furfurylation process does have an effect on the colour of the wood, darkening it. However, this can be an advantage in some cases as it can give the impression of the softwood being a tropical hardwood.

Impregnation methods of wood modification increase both the density and hardness of treated timber by introducing small molecular compounds into the wood structure. These compounds bind together and fill the voids that are usually filled with air in the dry wood.

Suitability of wood modification methods for different wood species

 

Accoya

Accoya

Accoya

Accoya is an acetylated wood, which has been used to create a variety of products including windows, doors, decking, cladding and structural beams. The modification process improves the dimensional stability of the wood.

Manufacturer Accsys Technologies
Applications Windows, doors, decking, cladding, louvres, bridges and building structures
Type of wood modification Chemical
Wood modification treatment Acetylation
Wood species Radiata and alder
Wood country of origin Northern Europe
Density 510kg/m³
Bending strength 39N/mm²
Sustainability certification PEFC, FSC, Cradle to Cradle Gold
Place of manufacture Europe

www.accoya.com

Medite Tricoya

Tricoya

Medite Tricoya

Formed using the acetylation process, Medite Tricoya wood composite panels are high strength, lightweight, provide good levels of insulation and are easy to machine. Its dimensional stability and resistance to funghi make it superior to standard MDF products.

Manufacturer Coillte Panel Products
Products Wood-based composite panels
Applications Window/door components, fascia/soffit panels, furniture, signage, internal partitions
Board thickness 6mm, 9mm, 12mm, 15mm, 18mm
Board size 1,220mm x 2,440mm
Type of wood modification Chemical
Wood modification treatment Acetylation
Density 700-720kg/m³
Sustainability certification FSC
Guarantee 50 years
Place of manufacture Europe

www.meditetricoya.com

LamboWood

LamboWood

LamboWood

LamboWood is modified through heat treatment and no chemicals are added to the wood. The wood is raised to a temperature of 210°C. This modification process does affect the strength of the wood, making it 20 per cent weaker than untreated pine.

Manufacturer Houthandel Lambert van den Bosch
Applications Cladding, fascias and soffits, internal wall coverings
Type of wood modification Thermal
Wood modification treatment Heat treated at 210°C
Wood species Pine, poplar and birch
Sustainability certification PEFC
Recyclability Reuse, recycle, incinerate
Place of manufacture The Netherlands

www.lambertvandenbosch.nl

ThermoWood

ThermoWood

ThermoWood

ThermoWood is a heat-treated timber cladding product. The heat treatment changes the chemical makeup of the timber, making it less able to absorb moisture. This restriction of moisture movement limits any potential for swelling, shrinkage or distortion.

Manufacturer Metsä Wood
Applications Cladding
Type of wood modification Thermal
Wood modification treatment Heat treated at 210°C
Wood species Scandinavian redwood
Wood country of origin Finland
Density 350-480kg/m³
Moisture content 5-7 per cent
Sustainability certification PEFC
Guarantee 30 years
Place of manufacture Finland

www.metsawood.co.uk

Platonium

Platonium

Platonium

Plato has developed a multiple-stage heat treatment system, which improves the dimensional stability and durability of wood while maintaining its mechanical properties. Non-durable softwood is modified to give it improved qualities.

Manufacturer Plato
Applications Cladding
Section sizes 18mm x 139mm
Lengths available 1,800mm-4,500mm
Type of wood modification Thermal
Wood modification treatment Two-stage heat treatment at less than 200°C
Wood species (origin) Spruce (Norway)
Density 290-420kg/m³
Bending strength 14-40N/mm²
Sustainability certification FSC, PEFC
Place of manufacture The Netherlands

www.platowood.com

PlatoWOOD Decking

PlatoWOOD Decking

PlatoWOOD Decking

The two-stage treatment used to modify PlatoWOOD improves both the durability and dimensional stability of the timber but, despite this, mechanical damages and splintering can still occur after the modification process.

Manufacturer Plato
Applications Decking
Section sizes 27mm x 140mm
Lengths available 2,400mm-5,100mm
Type of wood modification Thermal
Wood modification treatment Two-stage heat treatment at less than 200°C
Wood species (origin) Spruce (Norway)
Density 290-420kg/m³
Bending strength 14-40N/mm²
Sustainability certification FSC, PEFC
Place of manufacture The Netherlands

www.platowood.com

Belmadur

Belmadur

Belmadur

The two-stage wood modification process impregnates the wood with the Belmadur solution, cross-linking the timber fibres before the wood is cured. This process was originally used by the textile industry to create ‘wrinkle-free’ fabric.

Manufacturer Münchinger
Applications Windows
Type of wood modification Chemical
Wood modification treatment Cross-linking
Wood species (origin) Scots pine (Germany)
Density 540kg/m³
Bending strength 109N/mm²
Sustainability certification FSC, PEFC
Recyclability Reuse, recycle, incinerate
Place of manufacture Germany

www.muenchinger-holz.de

Kebony Cladding

Kebony Cladding

Kebony Cladding

The Kebonisation process impregnates the timber with furfuryl alcohol - an agricultural bi-product. This process gives the wood a darker colour, making Kebony wood resemble teak, ipé or mahogany. It gains a silvery-grey colouring as it weathers with time.

Manufacturer Kebony
Applications Cladding
Profiles available Rectangular, shiplap, grooved
Length available Up to 5,400mm
Type of wood modification Chemical
Wood modification treatment Kebonisation
Wood species (origin) Scots pine, beech, southern yellow pine, ash (Norway)
Density 600-680kg/m³
Sustainability certification FSC, PEFC
Recyclability Reuse, recycle, incinerate
Place of manufacture Norway

www.kebony.com

Kebony Decking

Kebony Decking

Kebony Decking

Due to the wood modification treatment, Kebony decking requires no maintenance and has a lifecycle of at least 30 years. Due to its hardness, Kebony decking is also more resistant to general wear than other wood types.

Manufacturer Kebony
Applications Decking
Profiles available Nine
Length available Up to 5,400mm
Type of wood modification Chemical
Wood modification treatment Kebonisation
Wood species Scots pine, radiata
Wood country of origin Norway
Density 600-680kg/m³
Moisture content 12-16 per cent
Sustainability certification FSC, PEFC
Place of manufacture Norway

www.kebony.com

Lunawood cladding

Lunawood Cladding

Lunawood Cladding

Heat treatment modifies the timber, creating what is known as a thermowood. This can be used for external cladding and internal wall finishes. Exterior cladding boards should be protected against UV radiation with tinted oil, wax, wood finishing products or paint.

Manufacturer Lunawood
Applications Cladding, internal wall coverings
Profiles available Three
Type of wood modification Thermal
Wood modification treatment Heat treated between 160 and 250°C
Wood species Pine, European ash, radiata
Wood country of origin Finland
Moisture content 5 per cent
Sustainability certification PEFC
Recyclability Reuse, recycle, incinerate
Place of manufacture Finland

www.lunawood.fi

LunaDeck

LunaDeck

LunaDeck

LunaDeck is not recommended to be used in constant direct contact with ground or water. The decking should be treated using wood oil or a stain, varnish or paint to protect the surface finish from UV damage.

Manufacturer Lunawood
Applications Decking
Profiles available Two
Type of wood modification Thermal
Wood modification treatment Heat treated between 160 and 250°C
Wood species Pine, European ash, radiata
Wood country of origin Finland
Moisture content 5 per cent
Sustainability certification PEFC
Recyclability Reuse, recycle, incinerate
Place of manufacture Finland

www.lunawood.fi

RETIwood

RETIwood

RETIwood

The retification process modifies the wood through the use of heat alone, without the addition of any chemicals, but relies on good quality timber being used from the beginning. The process modifies the timber’s hydrophilic and dimensional stability. It also affects its mechanical performance.

Manufacturer RETIwood
Applications Cladding, windows, floorboards, decking
Type of wood modification Thermal
Wood modification treatment Retification, which heats the wood to 180°C, then to 240°C
Wood species (origin) Spruce, pine, Scotch fir, poplar, beech, ash (France)
Density 415kg/m³
Sustainability certification PEFC
Recyclability Reuse, recycle, incinerate
Place of manufacture France

www.retiwood.com

 

 

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