Just like every human being is uniquely attributed with abilities and talents, wood also possesses its own set of distinct properties which determine its identity and nature.
These properties not only vary from one tree to another but also depend on the directional nature of the wood.
Therefore, even the same type of wood would exhibit varying traits which would be in accordance with its direction namely longitudinal, tangential or radial.
Since wood has many inherent characteristics, these could be broadly classified as being physical and mechanical properties and could be stretched to include thermal and electrical properties as well.
All categories, however, are influenced by some common factors like anatomy and moisture content and there are times when mineral and extractive contents have been known to play a seminal role as well.
An important physical property of wood which is probably tested right at the beginning is the moisture content, which is defined as the ratio between mass of water present within the wood to the mass of same amount of dry wood.
Normally this figure is expressed as a fraction or a percentage and ranges between 8 and 13%.
This property is particularly borne in mind by the wood processing industry since it impacts the wood's durability and performance.
Density of the wood is an essential physical attribute and is determined by assessing the amount of cell wall substance as compared to the volume of voids caused by the cavities of the fiber.
Close observation of the growth rings of wood would reveal a variation in density with the over all density being the percentage of early wood and late wood characterizing each growth ring.
When the moisture content of the wood diminishes beyond a certain saturation point, the wood starts shrinking with the amount of shrinkage being determined by the grain orientation and the amount of moisture lost.
Shrinkage has been known to occur more in radial and tangential directions as compared to longitudinal directions.
Other physical properties of wood include permeability and insulation, the former depending on the species of the wood and the attributes of the fluid and the latter indicating the electric resistance of wood.
The mechanical properties of wood include elasticity, strength and vibration characteristics and these are determined by factors like the species, moisture content, grain orientation and size and location of knots.
Elasticity of wood is a concern during its transportation and commercial applications while vibration in form of damping and sound velocity comes in handy during structural applications.
Strength on the other hand, is inversely proportional to size, meaning the smaller the piece of wood the greater is its strength.
Wood displays certain thermal properties as well and primary among them are conductivity, specific heat and coefficient of thermal expansion.
Conductivity in wood has been found to be greater in the longitudinal direction as compared to transverse although much of the heating during processing operations occurs along transverse lines.
Knowledge of thermal properties of wood is particularly useful because it is subjected to heat as a part of many processes like drying, curing, conditioning and pressing.
These properties not only vary from one tree to another but also depend on the directional nature of the wood.
Therefore, even the same type of wood would exhibit varying traits which would be in accordance with its direction namely longitudinal, tangential or radial.
Since wood has many inherent characteristics, these could be broadly classified as being physical and mechanical properties and could be stretched to include thermal and electrical properties as well.
All categories, however, are influenced by some common factors like anatomy and moisture content and there are times when mineral and extractive contents have been known to play a seminal role as well.
An important physical property of wood which is probably tested right at the beginning is the moisture content, which is defined as the ratio between mass of water present within the wood to the mass of same amount of dry wood.
Normally this figure is expressed as a fraction or a percentage and ranges between 8 and 13%.
This property is particularly borne in mind by the wood processing industry since it impacts the wood's durability and performance.
Density of the wood is an essential physical attribute and is determined by assessing the amount of cell wall substance as compared to the volume of voids caused by the cavities of the fiber.
Close observation of the growth rings of wood would reveal a variation in density with the over all density being the percentage of early wood and late wood characterizing each growth ring.
When the moisture content of the wood diminishes beyond a certain saturation point, the wood starts shrinking with the amount of shrinkage being determined by the grain orientation and the amount of moisture lost.
Shrinkage has been known to occur more in radial and tangential directions as compared to longitudinal directions.
Other physical properties of wood include permeability and insulation, the former depending on the species of the wood and the attributes of the fluid and the latter indicating the electric resistance of wood.
The mechanical properties of wood include elasticity, strength and vibration characteristics and these are determined by factors like the species, moisture content, grain orientation and size and location of knots.
Elasticity of wood is a concern during its transportation and commercial applications while vibration in form of damping and sound velocity comes in handy during structural applications.
Strength on the other hand, is inversely proportional to size, meaning the smaller the piece of wood the greater is its strength.
Wood displays certain thermal properties as well and primary among them are conductivity, specific heat and coefficient of thermal expansion.
Conductivity in wood has been found to be greater in the longitudinal direction as compared to transverse although much of the heating during processing operations occurs along transverse lines.
Knowledge of thermal properties of wood is particularly useful because it is subjected to heat as a part of many processes like drying, curing, conditioning and pressing.
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