Explanation

Refers to the secondary xylem of woody plant vascular tissue, which is formed from the inward part of the cambium, that is, the cellular tissue between the pith and the phloem is used as the raw material. Wood obtained from gymnosperms is called coniferous wood; Wood obtained from dicotyledons in some angiosperms is called broad-leaved wood. In Britain, the United States and other countries, softwood and hardwood are commonly called softwood and hardwood. wood is composed of cellulose, semi cellulose and lignin. Wood is a porous and anisotropic materials, which has different properties in radial, transverse and chord directions. It has the characteristics of light weight, strength to weight ratio, easy to make various shapes of wooden products, wooden components, and art crafts, and has good insulation. Among the traditional building materials, wood has the best insulation performance. The heat loss is only 1/6 of ordinary brick, 1/5 of ordinary concrete, 1/390 of steel, 1/1700 of aluminum, and the electrical conductivity is poor. It is often used as an insulating materials with beautiful patterns and natural and elegant colors, and is a good materials for decoration. Wood is the main product of the forest and a renewable resource that can be used forever. In addition to building, furniture, musical instruments, poles, crosstie, pitlogs and bridges, it can also be used to manufacture various multi-functional wood based-panel. The defects of wood, such as easy expansion and contraction, easy decay, easy moth, and flammability, can be improved through modification, anti-corrosion, insect prevention, flame retardant and other treatments to improve its utilization value.

Classification