Wood preservation is used to give wood with a low durability class a higher utilisation class. The types of wood we use for this are pine and spruce.
The usage classes we use are:
- Class 3: Wood exposed to weather, but not to the ground.
- Example: Garden fences in a wood-concrete fence.
- Class 4: Wood in permanent contact with soil or water (fresh water).
- Example: Wooden fence posts in the ground.
The method used for this is called the vacuum pressure method and is achieved in an autoclave with a preservative.
The preservatives and end products:
Class 3: Green (Basic copper carbonate main component)
Class 3: Brown (Basic copper carbonate main component)
Class 3: Red (Propiconazole main ingredient)
Klasse 4: Groen (Basiskopercarbonaat hoofdbestanddeel)
Class 4: Brown (Basic copper carbonate main component)
We only use products that have been approved by the Board for the Authorisation of Plant Protection Products and Biocides.
Do you have questions about the impregnation agent used? https://toelatingen.ctgb.nl/
Operation of the autoclave:
An autoclave is actually just a large tube that can be hermetically sealed. In the autoclave there is a rail, on which the wood is driven in and out. When the wood is put on the carts, it must be secured (wood wants to float in a liquid).
When the wood is driven into the autoclave, it is completely sealed and brought under vacuum. In this way, all the oxygen is out of the boiler and the cells of the wood open up. The boiler is filled with impregnating agent, after which overpressure is applied. In this way, the impregnating agent is pressed into the wood.
The process is fully computerised. The computer calculates the amount of impregnation agent to be pressed into the wood and automatically stops when this amount is reached.