Under normal conditions, wood and its products will have a certain amount of moisture. In China, the percentage of water contained in wood and the percentage of wood after drying is defined as the wood moisture content.
How to Calculate Moisture Content and Its Importance to Wood
Water content calculation formula:
Among them: W—absolute moisture content of wood;
Gs - wet wood weight;
Ggoo - The weight of dry material.
The importance of wood moisture content
After the production of wood products is completed, the shapes and materials will not be changed. At this time, the key factors that determine the intrinsic quality of wood products are the wood moisture content and drying stress. Manufacturing companies need to correctly grasp the moisture content of wood products. When wood products reach an equilibrium moisture content when used, the wood at this time is the least likely to crack.
For high-quality wood products procurement departments, with the continuous growth of professional knowledge, more and more attention is paid to the moisture content of wood products. In the past, foreign buyers paid great attention to this indicator. Many wood manufacturers who export products and semi-finished products have profound experience.
Dry wood, the more dry the better?
When wood is placed in a certain environment, the moisture content tends to a balance after a long enough period of time, which is called the equilibrium moisture content of the environment EMC. When the moisture content of the wood is higher than the equilibrium moisture content of the environment, the wood will shrink moisture and vice versa.
Therefore, the drying of wood should be appropriate, and it should not be as dry as possible. Different regions and different uses have different requirements for wood moisture content.
The average annual average moisture content of wood in major cities in China
Beijing 11.4% Urumqi 12.1% Hefei 14.8%
Harbin 13.6% Yinchuan 11.8% Wuhan 15.4%
Changchun 13.3% Xi'an 14.3% Hangzhou 16.5%
Shenyang 13.4% Lanzhou 11.3% Wenzhou 17.3%
Dalian 13.0% Xining 11.5% Nanchang 16.0%
Hohhot 11.2% Chengdu 16.0% Changsha 16.5%
Tianjin 12.2% Chongqing 15.9% Fuzhou 15.6%
Taiyuan 11.7% Lhasa 8.6% Nanning 15.4%
Shijiazhuang 11.8% Guiyang 15.4% Guilin 14.4%
Jinan 11.7% Kunming 13.5% Guangzhou 15.1%
Qingdao 14.4% Shanghai 16.0% Haikou 17.3%
Zhengzhou 12.4% Nanjing 14.9% Taipei 16.4%
Water content laboratory measurement method
The method for measuring the moisture content of wood includes drying, electrical measurement, retorting, titration, and humidity. In the field of wood processing, the drying method is usually used.