1. TECHNICAL USE MATERIALS I: WOOD
© Federico Fernández Herrera
ENGLISH BILINGUAL 2º E.S.O. TECHNOLOGY
DIDACTIC UNIT # 3

2. Index:
Stone, Bronze, Iron Age. Nowadays' technical use materials.
Natural vs. artificial materials.
Wood. Actual relevance. Parts. Processing. Features.
Working with woods (measure, draw, fix, cut, smoothen, drill,
join, finish).
Derivative products (cardboard, paper). Wood samples.
Types of wood.
Enviromental Impact.

3. Stone, bronze, iron Ages. Nowadays'
technical use materials. (I)
Stone Age

4. Stone, bronze, iron Ages. Nowadays'
technical use materials. (II)
Bronze = Cu – Sn alloy
Cu = copper
Sn = tin Bronze Age

5. Stone, bronze, iron Ages. Nowadays'
technical use materials. (III)
Iron = Fe Iron Age

6. Stone, bronze, iron Ages. Nowadays'
technical use materials. (IV)
Woods 2º E.S.O.
Metals (ferric, non ferric)
Plastics 3º E.S.O.
Ceramics

7. Natural vs. artificial materials.
Features:
Conductivity (heat and electricity)
Hardness

8. Wood. Actual relevance. Parts.
Processing. Features. (I)
Wood is a natural material. Wood and stone were the first materials that man used. Wood has been used to light a fire,
to make wood weapons, to build boats, houses, etc. Some of these things arestill used today.
Woods. Actual relevance.
Parts:
Bark (inn. and out.)
Cambium
Sapwood
Heartwood
Medullary rays
Pith (medulla)

9. Wood. Actual relevance. Parts.
Processing. Features. (II)
od: part of the trunk with life. It´s the youngest part of the wood. Its colour is light. It Heartwood: the best quality part.
has a lot of sap.
dullary Rays: they are cracks from the center outwards.
k: the outer trunk´s part. It is a protector of the trunk..
Medulla: the inner trunk's part.

10. Wood. Actual relevance. Parts.
Processing. Features. (III)
Features:
density d = m / V
hardness H
resistance to traction, compression and bending
T, C, F (fiber direction)
conductivity (th.&el.)
durability (moisture, hygroscopicity, fungus, rot)

11. Wood. Actual relevance. Parts.
Processing. Features. (III)
Processing:
http://www.youtube.com/watch?v=cwwkO7m4bpY&NR=1
Planks, boards, beams, etc
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

12. Working with wood
measure and draw
Rip saw, backsaw and hacksaw. Wood Power Tools: circular saw, jigsaw and table saw.
saw
http://www.youtube.com/watch?v=EAgCi1J7Hl0&feature=player_embedded
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 Wood and big machines that cut and raise the trunk quickly.
smoothen (sand) drill
join and fix (glue, nail, screw)
http://www.youtube.com/watch?v=rM5g0Sk0AWo&feature=player_embedded
finish
(wax, varnish, paint, ink, lack)

13. Types of wood. Samples.
http://www.linalquibla.com/TecnoWeb/madera/contenidos/tiposmadera.htm
Poplar = chopo
Walnut = nogal
Oak = roble
Birch = abedul
Cherry = cerezo
Pine = pino
Ebony = ébano
Fir = abeto
Soft wood: resinous and evergreen trees, they
are easy to work with (pine, fir, poplar…)
Hard wood: deciduous trees like oak , walnut, ebony,…

14. Derivative products (I)(cardboard, paper).

15. Derivative products (II) (plywood,
chipboard, fiber board).
Artificial Boards: • Cheaper and bigger sizes than natural wood. • Completely flat and smooth. • 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.
Chipboards: Made with glued and pressed wood shavings.
We can paste plastic or natural wood sheets together to
get a wood best finish quality.
Fiber Boards: We can get them from
wood fibers pressed together at
high pressure and temperature,
glued with synthetic resin
(DM) or natural resin
(tablex).

16. Environmental impact
deforestation
recycling