In 2014 we started impregnating wood with an impregnation machine “SCHOLZ”

Pressure/Vacuum –Impregnation PL.

For chemical treatment of the wood we use environment-friendly impregnating liquid CELCURE C4, which is made in Sweden and does not contain harmful chrome and arsenic additions.

The wood impregnation process is fully automated in a closed vacuum autoclave. The size of the autoclave is 14 m (length) and 1.8 m (diameter); work pressure is 14 bar.

Wood treated like this will last considerably longer – for up to 20 years, although it depends on the type of tree, degree of drying and chemical treatment class. The impregnated wood can be used for building construction, terraces, wooden fences, bank reinforcement and in other places, where there is a contact with moisture and water, which results in faster wood deterioration and decay.

The vacuum pressure treatment is done in a special autoclave, where the following processes occur:

  • the vacuum: opens the tiniest pores of the wood and removes moisture from the surface of the wood as much as possible;
  • the pressure (up to 14 bar): permeates the protective liquid deep into the wood;
  • the vacuum: removes the excess liquid from the surface of the wood.

Spruce wood and pine wood are very different from each other in terms of composition; therefore, the impregnation result for these types of wood also differ, as well as the possibility to impregnate them.

Pine, depending on the moisture level, can absorb the protective liquid through all of the sapwood part reaching the core, whereas, for spruce, depending on the moisture level, it is possible to permeate the protective liquid into the wood 2-5 mm deep. Respectively, the lifespan differs significantly. 

Impregnation classes

The result of the impregnation can be affected by various factors, for example, type of tree, moisture and the impregnation process itself. Therefore, there are several treatment classes, from which we only use the 3rd and 4th class:

3rd class – UC3

For usage above the ground, in damp places without a roof, for terraces. Can be used in slightly damp ground(soil).

4th class – UC4

For usage in direct contact with water and in very damp grounds.

Lifespan for poles that are not dried and are impregnated with the 3rd class is 3-10 years. The thicker the pole and drier, sandier the ground, the longer the lifespan of the pole.

In order to ensure lifespan of up to 20 years, the poles that are used for pasture grounds, fences, bank reinforcements or for other similar things, need to be impregnated with the 4th treatment class. To impregnate the poles with the 4th class and get a high-quality result, the following conditions have to be met:

  • the poles have to be made out of pine wood;
  • before the impregnation the poles have to be dried, and the moisture cannot exceed 28 %;
  • the protective liquid has to be permeated into the wood reaching the core – through all of the sapwood part.

Wood drying

There are two drying chambers with a power of 110 m3 operating in the company. The drying process is fully automated and is remotely controlled with an electric remote.