Principle of thermal modification of wood

After thermal modification of wood not only beautiful, durable, environmental protection, also suitable for indoor and outdoor any wood use of building materials and decorative materials.Wood is composed of hemicellulose, cellulose, lignin and small amounts of the extract of composition.Hemicellulose heat-resisting performance is poorer, under the effect of high temperature, it first degradation, generate free acetic acid, and the release of acetic acid as a catalyst, and accelerated the hemicellulose hydrolysis into sugars.So after heating, wood hemicellulose content is significantly reduced, and with the degradation of hemicellulose, the hygroscopicity of hydroxy significantly reduced, thereby the hygroscopicity of lumber, dimension stability improved.

In addition, the formation of free acetic acid, and significantly reduce decay fungi favorite food, and inhibit the growth of the decay fungi from the food chain.Cellulose is the crystalline region and amorphous area coexist long molecular chain structure.The size of the cellulose hygroscopicity, depends on the size and the amorphous free hydroxyl number.Wood heating, the formation of free acetic acid, and degradation of cellulose microfibril in the amorphous region, reduce amorphous area, make cellulose crystallinity and crystal size increases, this also reduces the moisture absorption of timber, increased dimensional stability.Wood contains a small amount of extract is low molecular substances, resin acid, terpenoids, fat, wax, tannin, phenols, etc.Wood heating, most extract volatile, also reduce decay fungi food, thus improve the corrosion resistance of the wood.In addition, resin compounds such as volatile, also improve the wood paint and bonding performance.