Drying benchmarks for new tree species need to be established. Before establishing new drying benchmarks, it is necessary to understand the structure of wood and its physical and mechanical properties, especially the relationship between wood density and drying shrinkage coefficient, and use the drying benchmarks of tree species with similar properties as a reference. . Or saw small samples and dry them in a drying box to observe their drying conditions. You can also put all kinds of wood to be dried together for drying experiments to observe the drying conditions of various test materials, and then according to various The reaction of sawn timber to drying is carried out by tree species. The steps are as follows:

The basic principle and drying essence of dehumidification drying and conventional drying are the same. Both rely on the convection heat exchange between the hot air in the wood drying room and the wood to be dried, and the air heats the wood and absorbs the moisture evaporated from the wood. The main difference between the two is the method of dehumidifying the air.

Air drying of wood is commonly known as natural drying. Air drying of wood is to stack wood in an open courtyard or under a ventilated shed, and use the heat in the atmosphere to evaporate the moisture in the wood to dry it. Although the method of air drying wood may seem simple, the drying process involves many physical laws, such as combining atmospheric drying with other drying methods, is a way to save energy.

Internal wood cracking occurs inside the wood, cracking along the wood rays, such as honeycomb, also called honeycomb cracking. There are no cracks on the surface, only sawing can be found. But it is usually accompanied by uneven appearance or significant shrinkage, or charring, or lighter weight. This is characteristic of over-drying.

Surface cracks are longitudinal cracks that occur along the wood rays on the outer surface of sawn timber (usually the outer cut surface of a chord-cut board). It is caused by excessive surface tensile stress in the early stage of drying