TEACHERS NAMES:
SUBJECT:
BASIC TECHNOLOGY
CLASS:
YEAR 8
TOPIC:
PROCESSING OF MATERIALS
SUB-TOPIC:
WOOD
LESSON:
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7/17/2024 4:58 PM
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2
5 minutes
STARTER ACTIVITY
1.Why is CPR essential in first aid?
2.Give two key benefits of first aid.
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TOPIC: PROCESING OF MATERIALS - WOOD
LESSON OBJECTIVE(S)
At the end of the class students
should be able to;
i. Mention the stages of tree growth.
ii. Mention the processes of tree felling and the
implements used.
iii. Define wood conversion.
iv. Identify the methods of wood/timber conversion.
LESSON OBJECTIVE(S)
KEY WORDS
Felling
Logs
Planks
Marketable
Rift
Feller buncher
Cambium
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TEACHER INPUT: Growth of trees
Timber growth is the process of planting and nurturing
seedlings, until they grow into trees.
Trees grow in two main ways:
a) Vertical growth (primary growth): A tree grows vertically
downward, through the roots and shoots, and upward through
the stems, branches and leaves.
b) Horizontal growth (secondary growth): This is the process
where the cambium layer produces new layers of cells annually.
This growth increases the diameter of the tree to become the
trunk.
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7/17/2024 4:56 PM
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Vertical and horizontal growth
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7/17/2024 4:56 PM
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Felling of trees
i.
ii.
iii.
iv.
v.
Tree felling is the process of cutting down mature trees for commercial
purposes.
Tree felling can be done manually or mechanically.
In manual felling, an axe or chain saw is used.
In mechanical felling, a feller buncher is used. A feller buncher is capable of
rapidly cutting and gathering several trees.
The felled tree is called the log, while the person cutting down the tree is called
a feller or a lumber Man.
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7/17/2024 4:56 PM
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Processes and planning of tree felling.
a.
b.
c.
d.
e.
Slope of the ground must be considered
Tree shapes and leaning (curving trunk) must also be put into consideration.
The direction the tree is likely to fall.
Obstacles around the tree, such as buildings, roads, over-head power lines etc.
Clearing the surrounding of people and objects that may stand in the path of the
falling tree.
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Conversion of trees.
i.
ii.
iii.
Conversion of trees or timber is the process of splitting timber logs into
commercial and marketable sizes.
The marketable sizes are called planks and boards.
Conversion of timber is carried out usually at the sawmills.
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TEACHER INPUT: Methods of timber conversion
1)
PLAIN SAWING: This is the process of cutting parallel through the log. Plain sawn
wood planks are wider and flat.
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7/17/2024 4:57 PM
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7/17/2024 5:06 PM
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STUDENT TASK 1 - EVALUATION
i.
ii.
Differentiate between vertical and horizontal tree
growth.
Mention three (3) methods of timber conversion.
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STUDENT TASK 2
Using freehand, give a simple drawing of
plain sawing.
5 minutes
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7/17/2024 4:57 PM
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ASSIGNMENTS
◼
Examine your classroom, identify two (2) items
that are products of timber conversion.
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