TIMBER SEASONING
Is the process of drying timber or removing moisture of sap present in a freshly felled timbers under more or less controlled conditions is called as ‘Seasoning of Timber’. A well-seasoned piece of wood should have 10% to 12% of moisture equal to atmospheric humidity of a place.
Objectives of timber seasoning
The main objective is minimize shrinkage, warping and splitting.
To increase strength, durability and electrical resisting power.
And to protect it from the attacks of insects and fungus.
Methods for Timber seasoning
Natural Seasoning:
Timber pieces can either be stacked horizontally or vertically and the seasoning is carved out by natural air. Moisture content of wood can be brought down to about 10 – 20% by natural seasoning. Time required for natural seasoning of timber is around 120 to 180 days.
Artificial Seasoning:
Boiling:
In this method, the Timber is immersed in boiling water or exposed to the action of steam. This method is a quick process of seasoning the timber. The timber seasoned by this method becomes brittle and easy to break.
Chemical Seasoning:
An aqueous solution of chemical salts like common salt or urea have low pressure. If the outer layers of timber are treated with such chemicals the vapour pressure will reduce and a vapour pressure gradient is created.
The interior of timber, containing no salts, retains its original vapour pressure and therefore tends to dry rapidly. Corrosive effect of common salt is a drawback of this method.
Electrical Seasoning:
The logs of wood are placed in such a way that their two ends touch the electrodes. Electricity is passed through this setup. Wood being a bad conductor of electricity resists the flow of electricity. In this process heat is generated which results in drying of timber. The drawback is that the wood may split due to overheating.
Kiln Seasoning:
Is carried out in an air tight chamber under controlled conditions of circulating air, relative humidity and temperature. Desired degree of moisture content in attained. Time required for kiln seasoning is 12-20 days.
Water Seasoning:
The timbers like bamboo are placed in the flowing water. The flow of water takes away the sap wood. After one week the bamboo poles are removed from water and then dried out under shade. Timber loses its elasticity end becomes brittle as it is losing sap wood completely
Is the process of drying timber or removing moisture of sap present in a freshly felled timbers under more or less controlled conditions is called as ‘Seasoning of Timber’. A well-seasoned piece of wood should have 10% to 12% of moisture equal to atmospheric humidity of a place.
Objectives of timber seasoning
The main objective is minimize shrinkage, warping and splitting.
To increase strength, durability and electrical resisting power.
And to protect it from the attacks of insects and fungus.
Methods for Timber seasoning
Natural Seasoning:
Timber pieces can either be stacked horizontally or vertically and the seasoning is carved out by natural air. Moisture content of wood can be brought down to about 10 – 20% by natural seasoning. Time required for natural seasoning of timber is around 120 to 180 days.
Artificial Seasoning:
Boiling:
In this method, the Timber is immersed in boiling water or exposed to the action of steam. This method is a quick process of seasoning the timber. The timber seasoned by this method becomes brittle and easy to break.
Chemical Seasoning:
An aqueous solution of chemical salts like common salt or urea have low pressure. If the outer layers of timber are treated with such chemicals the vapour pressure will reduce and a vapour pressure gradient is created.
The interior of timber, containing no salts, retains its original vapour pressure and therefore tends to dry rapidly. Corrosive effect of common salt is a drawback of this method.
Electrical Seasoning:
The logs of wood are placed in such a way that their two ends touch the electrodes. Electricity is passed through this setup. Wood being a bad conductor of electricity resists the flow of electricity. In this process heat is generated which results in drying of timber. The drawback is that the wood may split due to overheating.
Kiln Seasoning:
Is carried out in an air tight chamber under controlled conditions of circulating air, relative humidity and temperature. Desired degree of moisture content in attained. Time required for kiln seasoning is 12-20 days.
Water Seasoning:
The timbers like bamboo are placed in the flowing water. The flow of water takes away the sap wood. After one week the bamboo poles are removed from water and then dried out under shade. Timber loses its elasticity end becomes brittle as it is losing sap wood completely
