The Tree - the basic podelochnyj a material for performance joiner's and plotnichnyh works. From it produce walls, roofs and roofs, floors and ceilings, partitions, doors, covers, platbands, furniture and other products. Wood rather easily gives in manual and machining, it a little teploprovodna and is durable enough. If to cut a tree trunk across it is possible to notice that it consists of a core and set of concentric rings - year layers (fig. 1).
1. A trunk Cross-section:
1 - a bark; 2 - kamby; 3 - a core; 4 - wood
The Core in the form of a dark friable fabric represents overgrown initial runaway of a tree. At coniferous breeds it lasts along a trunk directly enough, at deciduous - is twisting. It is the least valuable part of a trunk, from it wood usually starts to rot and in a growing tree the hollow is formed.
Round a core in the form of rings year layers on which number define age of a tree settle down. Any year layer is non-uniform on colouring, width and density.
Each year layer is more light to a core that speaks conditions of growth of a tree. If to cut a tree trunk lengthways it is possible to find out so-called serdtsevinnye the beams penetrating year layers. Serdtsevinnye beams are well visible in wood of an oak, a beech, a maple and a plane tree.
The Drawing received on a surface of wood as a result of cutting of fibres of year layers and serdtsevinnyh of beams, is called as a tree structure. The richer a structure (shades and structure of fibres are more various), the more valuably wood. Prominent features of a structure of a trunk (various width of year rings, non-uniform colouring, serdtsevinnye beams) consider at it raskroe on boards and bruski, at furniture manufacturing, use in the decorative purposes.