THE MEANING OF WOOD

          The wood is part of the plants in the form of the trees obtained from forest or natural results that can be utilized and processed in accordance with the advancement of technology.
Wood consists of four principal elements, namely Sellulose, Lignin, a substance ekstratif and minerals-mineral ash makers.
1. Sellulose is the greatest on wood, i.e. more or less 70% of the weight of the wood.
    Sellulose consists of Hollosellulose, Hemisellulose and Alphasellulose.
    Alphasellulose is the base material of the main manufacture of paper, plastic and
    textiles.
2. Lignin is part of wood forming approximately 18-28% of the weight of the wood.
    This serves as a fastener lignin units of wooden structures which provide firmness
    wood.
3. Extractive substances, wood Shaper is a component that provides properties such as
    color, aroma, taste and durability.

Ash forming minerals.
          If the wood is burned, sellulose and lignin can be burned out so ash forming minerals is lagging and weighs approximately 0.2 to 1% of the weight of the wood.
Parts of the wood.
1. Skin
2. Kambium
3. Wood gubal
4. Wooden terrace
5. Hearts

1. Skin.
the outer part is made of wood that functions as the protector of the parts of the wood against the influence of the nature of destroyers. In addition it is also the way the spread of food from the roots to the leaves and the whole piece of wood.
2. Kambium.
is a thin layer of wood that circle that serves as the growth of new skin-forming materials, namely that replaces the damaged/dead skin which is mostly out, whereas the nature of them functioning as a shaper of young/new wood with the wood can grow this kambium great.
3. Wood gubal.is part of the wood which is still alive and functioning as a retailer of food substances of the leaf throughout parts of the tree. Thick wood gubal between 2-5 cm, the color pink, soft and not durable in usage.
4. Wood terrace.
It is part of the wood which consists of dead cells that are derived from wood gubal and doesn't work anymore. Wood coloured older terrace and more durable in usage compared to wood gubal.
5. The liver.
It is part of the wood is at, part comes from the start, wood was first formed by kambium, whereas nature is very fragile.

Terms in the field of timber.
            In the field of timber we know terms like: fiber, the fiber Pattern, texture, the pores of the wood, the RADIUS and circle of the year.
a. Fiber.
Is the direction of the order of the cells of the wood. The fibers can be straight, wavy, and it can be twisted. How to know the wood fiber so that it seems clear by means of colored liquid dribbled on the surface of the wood, then the furrows formed due to the liquid that's colored showed wood fiber.
b. Patterns fiber.
the picture is formed on the surface of the wood because of the fibers of the wood. Wooden plank fiber pattern depends on how sawing wood dolok.
c. Texture.
There are an assortment of wood texture coarse, medium and fine. This depends on the relative size of wood-wood. If the wood has large cells then their texture will be harsh, and if the wood is small then the texture of their cells will be smooth.
d. the pores.
The term of the pores is actually the xylem cells that serve as the ingredient supplier materials, if truncated transverse Rod will give the impression of small holes, that's called pores.
e. wooden fingers.
Is the network radial or wood tissue formed by the arrangement of cells in the radial, the meaning is from the outside to the Center.
f. the circle of the year.
The stack is a circle circle around the axis of the stem, consisting of parts that are lighter colored rift while the darker colour is dense in Alternately. Circle this year formed within one year.

Classification Of Wood.
          Wood generally divided into two types, namely: hardwood and soft wood.
The characteristics of soft wood.
a. narrow Daunya/small.
b. wooden Color light.
c. his BD.
d. Not durable in usage.

The characteristics of hardwood.
a. Daunya wide.
b. the colour is darker.
c. BD high.
d. Durable in usage.

Based on the weight of the wood type wooden class then can be classified as follows: 
a. The very heavy, his BD > 0.90.
b. The weight, his BD between 0.75-0.90.
c. The medium, his BD between 0.60-0.75.
d. The light, his BD less than 0.60.

Examples of very heavy wood   : Breaking loose, Ulin.
Example of heavy timber           : Lime, Kulim.
Examples are wood                    : Teak, Rosewood.
Example  light wood                  : Pine, Sengon, Suren, Balsa.

Based on the class of durability of wood are classified into:
a. Grade durable i: Oboni, rosewood, sapodilla and ulin.
b. durable Class II: sandalwood, rengkas and weru.
c. durable Class I-II: Johar, teak and merbahu.
d. durable Class III: Keruing, mahogany and sungkai.
e. durable Class II-III: nyatoh and FIR, Lime.
f. durable Class I-III: wood Bengkirai.
g. durable Class IV: pine, Ramin and Trembesi.
h. durable Class III-IV: Meranti.
i. durable Class V: Balsa, Randu pedestal and ylang.
j. durable Class IV-V: Sengon and frankincense.

Based on the hardness of the wood are classified into:
a. Wood very hard: Giam, Ulin and breaking loose.
b. hardwoods: Kulim, lime and Sonokeling Wood c. were: Red meranti and Teak.
d. soft wood: pine, sengon, suren and Balsa.

Set the hardness of the wood can be in the following way: 
The wood is cut transversely (transverse fiber), then the perceived impression of their campaign and observed the resulting piece of shiny surfaces, then the wood including hardwood. If the impression of small opposition, meaning easy to cut, as well as the resulting piece of rough areas, then the wood is soft.