UNIDAD 5. LA MADERA. UNIT 5. WOOD

Transcription

1 UNIDAD 5. LA MADERA. UNIT 5. WOOD WHAT IS WOOD? -RAW MATERIAL -MATERIAL -TECHNOLOGY PRODUCT THE ORIGIN OF WOOD IS. - ANIMAL ORIGIN -VEGETABLE ORIGIN -MINERAL ORIGIN 1

2 WHAT IS WOOD MADE OF? Wood is made of grains (fibras) called cellulose (celulosa) that are stuck with another material called lignine (lignina). A lot of these substances together are what we call trunk (tronco) and branches (ramas); or all joined a tree (árbol). 4

3 QUESTIONS? The name of the grains that are made of the wood are called: The name of the substance that join the grains is: María Díaz Parra lignin cellulose BRANCH TRUNK 5

4 PARTS OF A TRUNK If we cut a tree, we can see that the trunk is formed by several rings, every ring has a name and several properties. BARK CAMBIUM SAPWOOD HEARTWOOD PITH 6

5 PARTS OF A TRUNK BARK: Protect the tree from dangers such as animals, fire, CAMBIUM: Thin and transparent is situated between: bark and sapwood SAPWOOD: Is young wood and very soft, because of this, it is very difficult to work with it because it breaks easily. HEARTWOOD: Is dry wood, its colour is dark and very hard and strong. This part of the trunk is the best to make chairs, tables, etc. PITH: Is situated in the middle of the trunk and it is not used for anything. 7

6 PROPERTIES OF THE WOOD DENSITY : Wood has less density than the water, for this property the wood stays a float. POROUSITY: Wood is porous like a sponge, it absorbs water. This makes wood change its shape and swell (hincharse) INSULATOR: Wood is a good electric and thermal insulator. MECHANICAL PROPERTIES: Wood is ductile, malleable and tenacious. ECOLOGICAL PROPERTIES: Wood is recyclable, biodegradable and renewable. 8

7 QUESTIONS ABOUT PROPERTIES OF WOOD Wood is used in houses to insulate the walls because it is a : A good thermal conductor A bad thermal conductor What property makes wood stay a float on water?: Porousity Density Why a table of wood can not get wet? : Because wood is an electrical conductor and it s dangerous in a storm Because the table is porous and it swells with water What property makes wood have shape of sheets?: Malleability Ductility 9

8 PROCESS OF OBTAINING WOOD 1 1. FELL (TALAR): We fell the tree with an axe or a power saw (sierra mecánica). 10

9 PROCESS OF OBTAINING WOOD 2 2. PRUNE (PODAR): With axe or power saw we cut its branches 11

10 PROCESS OF OBTAINING WOOD 3 3.TRANSPORT : The logs are transported by road transport, train transport or river transport. 12

11 PROCESS OF OBTAINING WOOD 4 4. TAKE BARK OFF (DESCORTEZADO): We take off the bark of a tree with mechanical rollers (rodillos mecánicos). 13

12 PROCESS OF OBTAINING WOOD 5 5. CUT INTO BOARDS (TRONZADO): The branches and trunks: we cut them into boards of different sizes. 14

13 PROCESS OF OBTAINING WOOD 6 6. THE WASHING (LAVADURA): Boards are submerged in water to eliminate the sap and to protect wood from bugs (insectos),... 15

14 PROCESS OF OBTAINING WOOD 7 7. DRYING (SECADO): We dry the boards to eliminate water NATURAL DRYING (SECADO NATURAL): We pile up boards, protecting them from rain and sun, letting air go through them Inconvenience: It is very very slow, months even years ARTIFICIAL DRYING (SECADO ARTIFICIAL): We put boards into ovens (hornos) to speed up the process. Inconvenience: It is very very expensive. 16

15 PROCESS OF OBTAINING WOOD 8 8. PLANE (CEPILLADO): We plane boards to make the surface softer. 17

16 PROCESS OF OBTAINING WOOD 9 SUMMARY 1. FELL 8. PLANE 2. PRUNE ARTIFICIAL DRYING NATURAL DRYING 7. DRYING 3. TRANSPORT 6. THE WASHING 4. TAKE BARK OFF 5. CUT INTO BOARDS 18

17 CLASSIFICATION OF WOOD 1 We can classify wood in two kinds: 1. HARD WOOD(MADERA DURA) 2. SOFT WOOD(MADERA BLANDA) 19

18 CLASSIFICATION OF WOOD 2 HARD WOOD María Díaz Parra CHARACTERISTICS: - IT COMES FROM TREES WITH DECIDUOUS LEAF (HOJA CADUCA) - IT GROWS VERY SLOWLY - AND HAS VERY LITTLE RESIN (RESINA) EXAMPLES: - BEECH (HAYA ) - OAK (ROBLE) - CHERRY TREE (CEREZO) - MAHOGANY (CAOBA) 20

19 CLASSIFICATION OF WOOD 3 SOFT WOOD CHARACTERISTICS: - MOST OF THEM COME FROM TREES WITH PERENNIAL LEAF (HOJA PERENNE) - IT GROWS FASTER THAN HARD WOOD TREE - AND HAS A LOT OF RESIN (RESINA) EXAMPLES: - PINE (PINO) - FIR (ABETO BLANCO) María Díaz Parra - SPRUCE(ABETO ROJO) - POPLAR (CHOPO) 21

20 BY-PRODUCTS OF WOOD 1 DERIVADOS DE LA MADERA We can use grains or shavings to do other materials: 1. PREFABRICATED WOOD (MADERA PREFABRICADA) 2. CELLULOSIC MATERIALS (MATERIALES CELULÓSICOS) 22

21 BY-PRODUCTS OF WOOD 2 1. PREFABRICATED WOOD We can classify fabricated wood in 4 kinds: Plywood (contrachapado) Chipboard (aglomerado) 23

22 BY-PRODUCTS OF WOOD 3 1. PREFABRICATED WOOD Grain board (tableros de fibras) Tablex (Táblex) 24

23 BY-PRODUCTS OF WOOD 4 2. CELLULOSIC MATERIALS These materials are made of cellulose. Examples: The most important is paper - cardboard (cartón) - thin cardboard (cartulina) María Díaz Parra - tissue paper (papel de seda) 25

24 TOOLS BENCH VISE HOT GLUE GUN CLAMP 26

25 TOOLS SQUARE COPING SAW ELECTRICAL SCISSOR 27

26 TOOLS FILE RASP RASP PAPER OR SANDING RASP 28

27 TOOLS SCREW DRIVERS SCREWS HAMMER NAILS 29

28 TOOLS UNIVERSAL PLIERS WIRE CUTTERS OR DIAGONAL PLIERS NEEDLE NOSE PLIERS 30

29 An INSULATOR is a material that insulates something. Fat is an excellent insulator against the cold. SHAVINGS are small very thin pieces of wood or other material which have been cut from a larger piece. PLAYWOOD is wood that consists of thin layers of wood stuck together CHIPBOARD is a hard material made of very small pieces of wood which have been pressed together. TABLEX you can find it on the back of your wardrobe or usually in whatever furniture. 31