2. Historical Introduction:
Wood is a natural material. Wood and stone were the first
materials that man used.
Wood is used to light a fire, to make
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weapons, to build houses, etc.
Some of these things are used today.
3. The Tree’s Trunk
Sapwood: part of the trunk with life. It´s the Heartwood: the best quality
youngest part of the wood. Its colour is light. part.
It has a lot of sap.
Medullary Rays: they are
cracks from the center
Wood
outwards.
Bark: the outer trunk´s part.
It is a protector of the
trunk..
Medulla: the inner trunk´s
part.
4. Obtaining Wood
We can extract wood from a tree that is not too young or too old, it
depends on the different species
To extract wood we follow these
steps:
Life rings let us know
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Cut down the trees
tree´s age. The clearest
rings belong to spring and Clean the branches and the bark
the darkest ones belong
to autumn.
Transport
Cut the wood
Dry it
Distribution
5. To Cut Trees.
The trees are cut in the winter, because they have less
sap.
•The tools to cut trees were the axe and
the hand saw.
•The tools used today are the chainsaw
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and big machines that cut and raise the
trunk quickly.
6. To Cut Trees.
It is necessary to plant trees
again to have wood in the
future. This prevents
deforestation.
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7. Cleaning the trunks
First the trees are cut down and then the
branches and the bark are cut.
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Transportation
From the beginning the trunks were
transported by the rivers´ flow.
Today the trunks are
transported by big lorries.
8. To cut the wood
The trunks go to the sawmill.
Here the worker marks the lines
to cut the wood. This
woodcutter makes
planks, boards, beams, etc.
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The tools to cut the wood are:
traditionally circular saws and today big
electrical machines or machines with engines.
9. Drying the wood
After cutting the wood, It´s necesary to dry
in order to evaporate the sap and the
water. The wood is stacked to allow air to
flow.
It is faster with hot air.
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The distribution of wood
The cured wood is taken to the
factories.
10. Properties of wood
•The wood is hygroscopic.
•The wood is a bad conductor of electricity and heat. So the wood is a
good insulator.
•Most wood has medium density (<1000 Kg/m3),except some like the
ebony and other tropical wood.
•There is very soft wood like that of poplar trees or balsa and very hard
Wood
like oak or ebony.
•The wood has good mechanical endurance in parallel direction to the
fibres and less mechanical resistance in perpendicular direction to the
fibres.
•Durability: there is wood that is very resistant to fungus and parasites
like walnut, mahogany…and there is other wood less durable like pines
and eucalyptus.
11. Types of wood:
The most common classification of wood is :
•Soft wood: resinous and evergreen trees, they are easy to
work with (pine, fir, poplar…)
•Hard wood: deciduous trees like oak , walnut, ebony,…
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Some interesting web links:
• Wood´s Web (ES)
• Wood´s Kinds (ES)
• Wood in Kalipedia (ES)
• Wood´s Kinds 2 (EN)
• Wood´s Kinds 3 (EN)
12. Types of wood:
Exercise: make a Power Point or an Impress presentation with
the different kinds of wood . You must show the main properties
and applications of every one.
Below you can see an example in Spanish.
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13. Wood Derivatives
Artificial Boards:
• Cheaper than natural wood.
• Completely flat and smooth.
• Bigger size than natural wood.
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• Will not rot and it´s termite resistant.
Plywoods: Made with
wood sheets with
perpendicular fibers and
are stuck together. These
boards always have an
uneven number of sheets.
14. Wood Derivatives
Chipboards: Made with
glued and pressed wood
shavings. We can paste
plastic or natural wood
sheets together to get a
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best finish quality.
Fiber Boards: We can get
them from wood fibers
pressed together by high
pressure and glued by
synthetic resin (DM) or
natural resin (tablex).
15. Wood Derivatives
Paper:
• Resistant
• Enduring
• Hygroscopic
• Light
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• Heat insulator
• Electric insulator.
Cardboard:
•Obtained from a thick sheet of pulp
paper.
• Light and resistant.
• Used in packaging.
16. Woodworking
To measure and to
mark To fix To cut
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To split To drill To smooth
To finish
17. Woodworking Tools:
To measure and to mark
• Compass
• Flexometer
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• Square
To fix
Vise, bar clamp and C-clamp.
18. Woodworking : Tools
To cut
Hand Tools: Rip saw, backsaw and
hacksaw.
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Power Tools: circular saw, jigsaw and
table saw.
