Therming of wood - heat treatment of wood

Autoclaves for drying and therming/polymerization of wood

Therming of wood - heat treatment of wood

Wood therming (also known as wood heat treatment) is a process in which wood is subjected to elevated temperatures under controlled conditions to improve its performance. The purpose of this process is to change the structure of the wood so that it becomes more resistant to moisture, fungi, insects and reduces its tendency to crack and deform. In addition, therming wood improves its dimensional stability and aesthetics (darker color).

The wood therming process is widely used in the production of furniture, floorboards, building materials and other products where high durability, aesthetics and weather resistance are key.

Ask about our products

How does wood therming work?

01. preliminary wood preparation

Before being thermalized, wood is usually dried to the appropriate moisture content (usually below 20%). This makes the therming process more efficient and does not lead to excessive cracking of the wood.

02. Heating

The wood is subjected to high temperatures in an atmosphere of steam or other gas. The temperature of therming usually varies between 160°C and 230°C, depending on the type of wood and the desired effect.

03. Chemical process

As a result of heating, some chemical components of wood, such as lignin and cellulose, are broken down, leading to a change in the structure of the wood. Lignin becomes less susceptible to moisture, and the wood becomes more stable.

04. Cooling

Once the right temperature is reached, the wood is gradually cooled to prevent excessive streching of the material and damage to it.

05. Treatment after therming

Once the therming process is complete, the wood can be further processed, such as sanding, varnishing or painting.

Benefits of therming wood

Increased resistance to moisture

Thermally treated wood is less absorbent, which prevents it from swelling and shrinking under the influence of changing humidity.

High resistance to fungi and insects

The heat treatment makes the wood less attractive to microorganisms, mold, fungi and insects (such as woodworms). This makes it more durable in outdoor conditions.

Increased dimensional stability

Thermally treated wood is less prone to cracking, warping and deformation, making it more stable in use.

Improved aesthetics

Heat treatment causes the wood to darken, giving it an attractive, deep color that is desirable in many products, such as furniture, parquets and facades.

Increased durability

By improving its resistance to the elements, wood becomes more durable, making it a suitable material for outdoor use, such as gardens, terraces and outdoor construction.

Types of wood therming

This is the most commonly used therming process, in which wood is heated in the presence of steam, allowing better control over the moisture content of the wood during processing. The steam prevents oxidation of the wood, resulting in a darker color and improved stability.

In this method, the wood is heated in an atmosphere of inert gases, such as nitrogen or carbon monoxide, which reduce chemical reactions and combustion of the wood, giving better control over the color and properties of the wood.

The wood is placed in kilns that can be either rotary (they rotate the material during processing) or fixed (where the wood remains stationary). In these kilns, the therming process is more controlled in terms of temperature and moisture content.

The wood therming process is widely used in the production of furniture, floorboards, building materials and other products where high durability, aesthetics and weather resistance are key.

Applications of thermally treated wood

Ask about our products

Disadvantages and limitations of wood therming

Reduction in mechanical strength

Under the influence of heat treatment, wood becomes less flexible and may exhibit lower compressive strength, which should be taken into account when selecting a material for specific applications.

Color variation

The color of wood after therming is more difficult to predict and can vary depending on the species of wood, which can affect the aesthetics of the final product.

Higher cost

The therming process requires specialized equipment and lengthy wood processing, which can increase production costs compared to traditional wood processing methods.

Summary

Wood therming is a heat treatment process that improves the mechanical and aesthetic properties of wood, increasing its resistance to moisture, fungi and insects, as well as its dimensional stability. Heat-treated wood becomes more durable and resistant to changing weather conditions, making it widely used in construction, furniture, flooring, garden materials and other products. Although the process involves higher production costs, its benefits in the form of increased wood durability and aesthetics are highly valued in many industries.

Scroll up