For material and bonding technologies, an important factor here is the fact that, in a stem section, from the center of the stem to the outside layers, the features of the wood change. In many species of wood, at the center of the stem there is the ‘heart’ where the storage cells (pith rays) are dead. Storage cells are located in the sapwood, which is mostly lighter in color and wrapped by the cambium layer (growth region) and bark. Each year, a new growth ring (annual ring) is formed, within which there are two portions: (i) early wood, which is more open-textured and formed early during the vegetation period; and (ii) late wood, which has narrow-volume cells that are formed in the autumn. The function of early wood is to conduct water and mineral salts, while the function of late wood is mechanical stabilization of the stem.
The Macroscopic Structure of Wood
19 ноября, 2015 
Pokraskin 
Опубликовано в рубрике Adhesive Bonding