By usage environment According to the usage environment, it is divided into outdoor grade carbonized wood and indoor grade carbonized wood.

The mature heat treatment processes abroad mainly include Thermo Wood from Finland, Plato Wood from the Netherlands, and Correction from France.

Chemical modification of wood: Chemical reactants react with hydroxyl groups in the wood cell wall polymer, leading to the formation of covalent bonds between the reactants and the wood matrix Wood thermal modification: Heating wood leads to a certain degree of degradation of its components, resulting in the desired improvement in wood properties Wood surface modification: Chemical, physical, or biological (enzyme) reagents are applied to the wood surface to achieve the desired performance improvement.

For a person engaged in wood drying production, it is best to have diligent eyes, ears, legs, mind, mouth, and learning.

In the drying room of the automatic system, the operator needs to input various parameters into the control system according to the drying benchmark conditions, and then start the operating device to make each actuator work and control according to the set values. The operator's job during duty is to record in detail the temperature of the drying medium and the specific values of the electromagnetic field. The automatic operating system has relatively low labor intensity for operators, but operators must have basic knowledge of wood drying production technology, be familiar with and master the specific performance of drying equipment. Otherwise, if problems occur during the wood drying process, they will be helpless, leading to drying defects in the wood and affecting the drying quality.

To ensure the smooth progress of the wood drying process, it is necessary to conduct a systematic inspection of the facilities in the drying room before each drying, especially the internal facilities. Otherwise, if problems occur during the drying process, it will seriously affect the production cycle and drying quality of wood drying, and also have an impact on the service life of the drying equipment. The equipment inspection before drying mainly includes the inspection of the various systems that make up the drying chamber.

Thermally modified wood namely carbonized wood/carbide wood, carbonized wood is divided into surface of carbonized wood and depth of the carbonized wood.

Drying wood in large,Kiln drying removes more of the moisture than air-drying, thereby helping to reduce the chances of the wood splintering and warping. In addition, it ensures that there are no insects or mold existing inside of the wood. Kiln drying can be a costly process, and as a result, it is used most commonly to dry wood that will be used in building projects, although it is sometimes used to make firewood.

At this stage, the moisture content inside the wood is already below the fiber saturation point. If the spray steaming treatment was not carried out in the previous stage, the outer wood would have lost its normal drying shrinkage condition and was fixed in a stretched state. Just like the incomplete dry shrinkage before the plasticization and fixing of the outer wood, the internal size and the outer layer are temporarily balanced, so the internal stress of the wood is also temporarily in a balanced state. At this time, if the test piece is sawed into a comb shape, the length of each tooth is temporarily the same, but after being placed, the moisture content decreases, and some teeth in the inner layer of the test piece will become shorter due to drying shrinkage.

Wood Internal Stress at Different Drying Stages The internal stress changes during wood drying can be divided into four stages. At the beginning stage of drying, the wood has not yet produced stress, and the moisture content of each part of the wood is above the fiber saturation point. If the test piece is cut from the middle of the material, the test piece is sawn into a comb shape, and the height of each tooth is the same as the sawn tooth. The original size before opening is the same. If the test piece is cut into two halves, each piece remains straight, which shows that there is no moisture content stress and no residual stress in the wood.