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Our product 


  Accoya® Wood Technology Changes Wood on a Molecular Level 


              The Problem: An abundance of chemically unstable groups in wood called “free hydroxyls” attract moisture through hydrogen bonding, 

                                   causing  wood to swell and shrink and creating an attractive environment for wood-decaying fungi and destructive insects

              Our Solution: The non-toxic acetylation process upon which Accoya® wood production technology is based blocks cyclical absorption. Acetylation                                     effectively changes the free hydroxyls within the wood to stable acetyl groups. 

                                   The acetyl levels of Accoya® wood surpass those of even in the most naturally durable wood species   

 Acetylation: The ideas behind the innovation 


            Wood fibres contain an abundance of chemical groups called ‘hydroxyls’ (-OH) absorb or release water causing 

          wood fibres to swell & shrinkone of the principal reasons that wood is prone to decay

 Acetylation transforms the hydroxyl groups to (also naturally occurring) acetyl groups, causing a strong reduction of water 


 The result

  • A non-toxic, fully recyclable wood
  • Modification to the core Can be cut or profiled without exposing unprotected surfaces 
  • Acetylated wood, changed at molecular leve 
  • A high durability achieved by stopping the rot fungi from digesting wood, not by killing them with toxi

 Cellular structure of softwood




      Dimensional stability and water uptake



Fibre Saturation Point

± 25 % wood moisture content

< 25% mc “bound” to cell wall

> 25% mc also “free” water in cell lumen  


 The Accoya® Wood Production Process



The Benefits of Accoya® Wood 






Accoya testing


  • Institutes around the world have been running long term exposure trials of acetylated wood
  • Including: USDA Forest Products Lab, BRE, UK, SHR, NL, Asia- China



Performance in all conditions positions our data as robust




   Testing update


SCION, NZ stake trial
• 10 year data reported
• Accoya continues to significantly exceed very durable wood types such as Merbau,CCA (full penetration H4) 



AWPC 5604 Mastotermis testing Northern Territory, Australia




Termite durability testing results

Testing results at the Louisiana State University and Mississippi State University following the rigorous testing protocols of the American Wood Protection Association (AWPA).

Accoya® wood offers outstanding durability against the most destructive of termites, having more than 20 times the resilience of untreated wood.

Dimensional Stability
Outdoor exposure siding trial
Accoya wood showed minimal cupping
- Dimensional Stability – 97.7%,  Allows use of wider siding boards, Improves coating life
IFT Rosenheim, Germany  thermal conductivity of Accoya 
Evaluation thermal conductivity of Accoya relative to joinery soft and hardwoods
•Thermal properties of components are critical to the window U value
•Accoya insulating value relative to:
−Hardwood 50% better
−Softwood  8% better

Thermal conductivity in wood is a function of moisture content & density. Accoya has advantages in both compared to hardwood, & in moisture content for softwood.



Hiroshima Technology Research Institute, Japan


 Test of radiant heat on Accoya, WPC and thermo-wood decking. Major   advantage for Accoya evident in thermograph images




Thermographs made on a sunny day with ambient temperature of 30°C



Accoya® Wood: A Green Building Material - Ecolabels for accoya®

Choices based on Technical credibility and Market influence
Environmental performance in various life cycles:
Wood sourcing: FSC, Nordic Swan, NL Greenlabel
Product health & quality: Singapore Green Label, the Future Build, Nordic Swan
Corporate Social Responsibility: Cradle to Cradle (C2C), Nordic Swan, NL Greenlabel
Life cycle performance including End-of-Life: C2C, NL Greenlabel
Leading green building certifications: BREEAM & LEED  
Naresuan University,Thailand (Testing location reference)
Accoya is demonstrating significantly higher performance than Makha hardwood & high quality Teak.
Set up at 5 sites across Thailand
• Test set up follow AWPA E7-09 and stakes evaluate by an ASTM D1758 scale
• 5 year conclusion: Accoya performance is ahead of old growth teak

1 of the 5 Naresuan test sites, left & close up of the old growth Burmese teak tested alongside Accoya &



Reference Project










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