TECHNICAL USE MATERIALS I: WOOD

Federico Fernndez HerreraENGLISH BILINGUAL 2 E.S.O. TECHNOLOGYDIDACTIC UNIT # 3

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.

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

Stone Age

Stone, bronze, iron Ages. Nowadays' technical use materials. (II)

Bronze = Cu Sn alloy
Cu = copper
Sn = tinBronze Age

Stone, bronze, iron Ages. Nowadays' technical use materials. (III)

Iron = FeIron Age

Stone, bronze, iron Ages. Nowadays' technical use materials. (IV)

Woods2 E.S.O.
Metals (ferric, non ferric)

Plastics3 E.S.O.
Ceramics

Natural vs. artificial materials.

Features:
Conductivity (heat and electricity)
Hardness

Wood. Actual relevance. Parts. Processing. Features. (I)

Woods. Actual relevance.
Parts:
Bark (inn. and out.)
Cambium
Sapwood
Heartwood
Medullary rays
Pith (medulla)

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 are still used today.

Wood. Actual relevance. Parts. Processing. Features. (II)

Bark: the outer trunks part. It is a protector of the trunk..

Medullary Rays: they are cracks from the center outwards.

Medulla: the inner trunk's part.

Heartwood: the best quality part.

Sapwood: part of the trunk with life. Its the youngest part of the wood. Its colour is light. It has a lot of sap.

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)

Wood. Actual relevance. Parts. Processing. Features. (III)

Processing:

http://www.youtube.com/watch?v=cwwkO7m4bpY&NR=1 CORTE EN EL BOSQUE

Planks, boards, beams, etc

After cutting the wood, Its 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

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.

http://www.youtube.com/watch?v=EAgCi1J7Hl0&feature=player_embedded ASERRADERO

Working with wood

measure and draw

saw


smoothen (sand) drill


join and fix (glue, nail, screw) finish (wax, varnish, paint, ink, lack)

Rip saw, backsaw and hacksaw. Wood Power Tools: circular saw, jigsaw and table saw.

http://www.youtube.com/watch?NR=1&v=jzyaGrpUpIA ENSAMBLES

Types of wood. Samples.

Poplar = chopo
Walnut = nogal
Oak = roble
Birch = abedul
Cherry = cerezo
Pine = pino
Ebony = bano
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,

http://www.linalquibla.com/TecnoWeb/madera/contenidos/tiposmadera.htm

Derivative products (I)(cardboard, paper).

Derivative products (II) (plywood, chipboard, fiber board).

Artificial Boards: Cheaper and bigger sizes than natural wood. Completely flat and smooth. Will not rot and its 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 fromwood fibers pressed together at high pressure and temperature, glued with synthetic resin (DM) or natural resin (tablex).

Environmental impact

deforestation


recycling

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