Thermally modified wood in Russia and prospects for increasing the production of thermally modified birch.

Thermo-wood and its manufacturing technology
Wood that has been evaporated with hot air without the use of any chemicals is called thermo-wood. This process results in a fire-resistant material that is protected from mold and mildew and is much more durable than untreated wood.

Thermo-wood is the result of a certain heat treatment of a number of coniferous and deciduous trees (for example: ash, oak, pine and especially birch). This material is also called thermally modified wood (TMW) or thermo-wood.

Boards that have been exposed to heat are ideal for the manufacture of structures intended for outdoor use.

The technology for producing such thermo-wood is a process that involves heating the fibers of the material to a high temperature. This is done in order to change its molecular composition and improve its properties.

The creation of thermo-wood occurs under the influence of high temperatures. In order to prevent the combustion of wood, special oxygen-free chambers are used.

Heat treatment can be single-stage or multi-stage.

Single-stage approach
This approach involves treating the wooden blanks with hot steam, the temperature of which is in the range of 150°c to 200°c, while the amount of oxygen in the chamber is reduced to 3.5%. This process can be used for boards that have been pre-dried for 3 days, or for green boards that require more than three days of drying.

Multi-stage approach
The multi-stage process takes place in a closed container, where the wood is exposed to hot steam at a temperature of 150 to 200 degrees, and a pressure of more than 1.6 MPa. It takes four days to complete the drying process, and the moisture content of the finished product should not exceed 10%.

There are also treatments for wood with oil and nitrogen.

Application of oil
This technique involves placing the logs in a vessel filled with oil and applying gentle heat. The wooden structure absorbs a limited amount of oil, as a result of which the ThermoWood becomes impermeable to moisture and resistant to destruction.

Nitrogen application
Using nitrogen with 2% oxygen or any other inert gas allows you to get the best quality wood.

The classification of steam-treated wood is determined by the temperature it was exposed to, and this changes its appearance and properties:

First class thermal timber. Thermal preparation – at a maximum temperature of 190 °, which allows you to get a small result in changes in fibers and small changes in color.
The working temperature for the second class is 210 ° C. It has greater resistance to wear and decay, as well as a darker shade.
Third class. The boards are heated to 240 ° C, as a result of which they acquire a darker shade, and the quality of the material becomes even better.

Properties of thermally modified wood. Advantages and disadvantages
Thermal modification of wood improves almost all of its qualities:

By achieving greater density in its structure, the wood prevents its ability to absorb moisture, reducing its hygroscopicity and making it more resistant to environmental influences.
The geometry and dimensions of the material will remain unchanged.
Durability. For example, soft wood species in processed form can become quite rigid and durable against any mechanical impact. In addition, there is no cracking of the material.
Safety. The boards become not only environmentally friendly, but also fireproof. They are practically non-flammable and burn poorly.
Durability. Thermally modified wood has a significantly longer service life in all areas of application.

Also, the following are considered properties of thermally modified wood, compared to conventional wood:

The weight after heat treatment is usually 5-10% less than the weight of untreated wood.
The sustainability of biological material increases by 25 times compared to natural wood.
Compressive strength and hardness of the material have increased more than twice.
Thermal conductivity of such wood is approximately 20-25% lower than that of organic wood.
In addition to the above characteristics, the boards become more attractive due to the rich shade and clearer lines of the wood.

In Russia, birch accounts for approximately 55% of deciduous trees, and not many timber processing companies know what to do with such volumes. Therefore, our company “Geoburo“ offers several options for birch processing, one of which is the production of thermally modified birch.

Thermally modified birch (thermo-birch) has relatively recently entered the practice of construction, finishing and furniture production. The main difference between heat treatment and conventional drying is the higher temperature of exposure to wood. To prevent combustion, the treatment is carried out in a protective environment created by special chambers. The technology consists of exposure to supersaturated water vapor at a temperature of 220-250 degrees. In the technology invented in Germany, the protective environment is an organic substance – sunflower, linseed, rapeseed and other vegetable oils.

Benefits of Thermally Modified Birch:
There are many benefits to using thermally modified birch to finish your home, making it a popular choice for many people building or remodeling their home.

Here are 10 key benefits of using thermally modified birch to finish your home:

Natural Beauty: Thermally modified birch has a beautiful natural color and texture that adds a natural and warm look to your home. It retains its natural beauty even without additional finishing coatings.

Resistance to Rot and Pests: The thermal treatment process makes the wood resistant to fungi, insects, and rot. This increases the durability of the coating.

Moisture Resistance: Thermally modified birch has increased resistance to moisture, making it an excellent material for wall cladding, even in humid conditions.

Dimensional Stability: After thermal treatment, the wood becomes more stable, less prone to shrinkage and deformation. This contributes to the durability and preservation of the appearance of the finish.

Environmentally friendly: Thermo-birch is a natural and environmentally friendly material that does not contain harmful chemicals. Its use promotes environmentally responsible construction.

Reduced seasonal expansion and contraction: Due to thermal treatment, Thermo-birch wood is less susceptible to the effects of variable temperatures and humidity, which reduces seasonal expansion and contraction.

Uniqueness: Advanced thermal treatment technology makes Thermo-birch unique in color and texture, which gives your home a unique and individual look.

Ease of processing: Thermo-birch is easy to process. It can be painted or coated with protective varnishes for additional protection from external influences.

Versatility of use: Thermo-birch is suitable for finishing both interior and exterior surfaces. It can be used for cladding walls, floors, ceilings, as well as for creating furniture and decorative elements.

What products can be made from thermally modified birch:

DECKING BOARD