29.5.13

The Beauty of Indonesia



Indonesia is an archipelago where most of Indonesia is widespread throughout the oceans. Indonesia therefore has the potential for a great sea include biological resources, mineral, and energy. With the potential of the sea then we can use it for recreation and marine scientific investigations.

23.5.13

NATURAL COLOUR OF WOOD (Part III)


Natural color of wood can change rapidly due to several causes, either by extractive substances contained therein as well as by influences from outside the timber. Examples of mahogany (Swietenia macrophylla) the color changed from pink or light red to red brown quickly on a piece of wood fresh. This color change can lead to defects in the wood color defects. Another term often used is the discoloration.
         
Discoloration is caused by defective color color changes which occur in wood caused by a variety of treatment without giving the dye. There are five factors that cause the occurrence of staining, namely: the influence of temperature and humidity, the process of oxidation, deposition of pigment on the surface of the wood, the influence of the organism and in contact with metal.

The color of wood exposed to the atmosphere often darken the wood and sapwood usually be darker than the wood paneling. These changes usually occur in the natural chemical produced by the oxidation reactions of organic components contained in the wood.

The color change can occur immediately after trees felled in the forest or wet after sawing logs into boards. Alder wood quickly changed color from whitish to reddish, then fade to brown. Black locust wood porch changed from light green to dark brown, while the Douglas fir becomes reddish.
        
Further stated also that the old wood exposed to sunlight, especially in the high plains, changing its color to brown. While prolonged exposure to rain or high humidity change the color of the wood becomes dark gray.
        
Discoloration on teak (Tectona grandis Lf) caused by the oxidation process of extractive substances in the wood.
As well as the study of sugi wood (Cryptomeria japonica). From some research it is known that the use of high temperatures in the drying of wood has caused the color change. This is caused by the discharge of extractive substances contained in the timber to the surface. As for the wood white or light colored wood and the sapwood, the changes can be caused by fungal attack. Wood is attacked is usually a blue or black. Generally, the wood was attacked while still in fresh condition with a high water content.

THE END

13.5.13

NATURAL COLOUR OF WOOD (Part II)



Wood from older trees may have older color (darker) when compared with the wood from younger trees of the same type. Dry wood in different colors when compared with the color of wet wood. Wood that has been stored in the open color can be darker or lighter than fresh wood, this depends on the circumstances (weather, wind, light, and so on). In general, the color of a particular type of wood is not a pure color, but color is a mixture of several kinds of colors, so that in appearance it is difficult to be expressed precisely in words.

As the Giver of Extractive Substances Natural Color Wood

The color of wood caused by a material that can be extracted, which are called extractive. Extractive is a chemical in a timber that can be dissolved in a neutral solvent such as water, ether, alcohol, benzene and acetone. The content of extractive in wood varies from less than 1% to more than 10% and can reach 20% for tropical timber. Each type of tree contains one or several kinds of extractive substances and only a few species of trees that contain all extractive substances.

Flavonoids, stilbena, tannins and anthocyanins is a class of dye wood extractive. Flavonoids are compounds that cause the wooden porch of red, yellow, brown or blue. Polyphenols and tannins in the wood broad leaves have a great contribution to the color of wood, especially wooden color terraces and in the past few broad leaves of wood used as dyes. Phenolic contained in a wooden porch, and a little skin in the xylem has a function as a fungicide and in addition it also serves to enhance the staining of wood.

Extractive substances is influenced by growth conditions. For example, differences in walnut color from different geographical locations, related to soil properties. Extractive chemical differences allow to distinguish between types of wood or made ​​of wood staining colorless terrace with the application of chemical substances. Some of the wood such as black locust, honey locust and some tropical wood species have fluorescent for extractive substances.

Color As One Of Wood Identification Tool

To know the properties of wood can be used either coarse (macroscopic properties) as well as structural properties (microscopic properties). Included in this is the rough nature of color, luster, smell, taste, texture, fiber and figures. While the nature of the observed structure consisting of pores, parenchyma, the radius, inter cellular channels, lymph channels, and skin inserted. Physical properties can be determined directly by the senses without having to use the tools on the contrary nature of the structure usually use aids in the form of a magnifying glass with magnification of 10 times.

Colors characterize the various types of wood, but it is a trait that is difficult to describe with words. In one species there may be differences and changes due to exposure or as a treatment. Usually the color is expressed visually, but can also be measured technically.

If we want to use color for identification, then the color used is wood paneling. Wood color sapwood usually less real or less typical, so less is diagnostic for the introduction of wood. The color of wood into a value that is important for identification. For example, ebony wood has the typical black color. To determine the exact color can be used Spectrophotometer instrument. This tool can reflect light from a number of different wood surfaces using ultraviolet light.

Further stated also that often there is a striking range of colors, followed by a variety of other colors, so it is difficult to split up individually. Due to the nature of color is easily changeable, then the use of wood in the identification of a secondary color, so it should be used with caution.

To be continued....

7.5.13

NATURAL COLOUR OF WOOD (Part I)

Wood has been used for various purposes by human beings since time immemorial. With a variety of uses, the wood still exist until today. Unlimited use of wood for household appliances (interior), but is also used for exterior purposes, e.g for the manufacture of the bridge. Meanwhile, with its colors and decorative patterns, some type of wood used to make objects of high artistic value.

As with other objects, the natural color of wood can be very interesting. People liked the teak wood such as strength and durability in addition to the already well-known is also because of the color and the s type. Some people like wood with bright colors, some are more like a darker-colored wood. But not a few who like both.

Color selection becomes very personal because it can express one's personal. Color is something that is unique because it can change the feel of the environment, creating a certain style, set the mood and alter perceptions. The color of the wood gives the characteristics for various types and is highly dependent on extractive substances it contains, though often difficult to express in words. This is because not only consist of one color but a blend of several colors.

Wood has a high decorative value caused by the color, type of fiber and pictures in wood. Furniture made of wood like this are usually given a transparent color to display its natural beauty. While the furniture or other equipment made of wood that do not have the color and pattern of interest, will be given a specific color in the finish resulting in better color. Often also objects or equipment that is not made of wood made as if made of wood by giving a certain finish so that it becomes similar to the color and pattern of certain wood.

Wood has natural colors vary widely. Generally, wood-colored sapwood younger or lighter than the wooden porch. While the wooden porch has more color variations, mainly brown with various shades. Because the color of the wood patio wood is usually preferred over the pig. Some types of wood are given special treatment such as soaking or vapor given to darken the color.

Wood color ranges from nearly white to black, some are plain and some are composed of two or more colors, so it looks like there s type. Pattern that existed at a particular type of wood can be caused by:

1. Color difference between early wood and late wood of the circumference grows.

2. Color difference network.

3. Staining intensity differences in the layers of wood formed in a different time period. On the ebony wood for example, there are layers of red-brown or brown and there are layers of black. In the radial and tangential field will appear as lines of red and black color turns brown.

To be continued...