The acetylation process increases the amount of acetyl molecules and reduces the amount of hydroxyls in the wood, which improves durability, dimensional stability, insect resistance and the service life of coatings
Furfuryl alcohol has a small molecular size. This allows impregnation into certain wood species, which is completed by a polymerisation in place.
This treatment is used to improve the structural characteristics (hardness), and to stabilize wood dimensions – together with a better resistance to insects and fungi. As it contains a high percentage of polymer, resistance to atmospheric conditions is greatly improved, so it can be used outside. It is also mostly used to change the aspect of wood, making low quality species look and feel like exotic timber.
The treatment requires 2 steps, impregnation in special high pressure plant with furfuryl alcohol, then curing in a heating plant. It is a long lasting treatment cycle, with expensive chemical, resulting in high added value to the finished product.