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.

A monitoring system for a wood drying kiln having a housing with an interior wall surface, an area within the housing for placement of a charge of wood for drying of the charge of wood, and means for heating and humidifying the interior of the wood drying kilns, the monitoring system comprising:

At this time, the moisture content of the wood has been distributed fairly evenly along the layers of the wood section, and the moisture content gradient from the inside to the outside is small. Stop shrinking, and the inner layer of wood should shrink with the removal of absorbed water, so that the shrinkage of the inner layer of wood is limited by the outer layer of wood, and the stress of the inner layer being stretched and the outer layer being compressed, the internal stress The situation is just opposite to that at the initial stage of drying. At this time, if the test piece is sawed into a comb shape, some teeth in the middle of the test piece are free to shrink after breaking away from the shackles of the outer layer, and their size is shorter than that of the outer layer.

There are various types of drying equipment, including hot air drying equipment, vacuum drying equipment, freeze drying equipment, microwave drying equipment, spray drying equipment and rotary drying equipment. Each type of drying equipment has its unique working principle and application scenarios, which can be selected based on the characteristics of the material and drying needs.

In recent years, "high-frequency vacuum drying" has become very popular. This technology has been adopted by many factories due to its advantages such as small footprint, fast drying speed, and environmental friendliness, and has rapidly emerged as an emerging method for wood drying.

1. Circular drying method This method is mainly applicable to wood such as Korean pine, Masson pine, and spruce. When operating, the wood needs to be divided into two parts: one part is placed in the center of the drying kiln, and the other part is placed around the drying kiln. This method can make the wood dry more evenly.

Drying process of wood drying kiln is divided into three phases, respectively, preheat treatment stage, intermediate stage of processing and normal drying stage.Must be strictly implemented in the process of drying drying process, good grasp of the temperature and time to prevent drying is not complete.

Using ThermoWood in place of regular wood presents several advantages, including but not limited to: Durability: As the wood is treated and becomes more resistant to the effects of insects, decay, and rot, ThermoWood can be used in a variety of outdoor applications without fear of degradation from weather exposure.

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.