Wood

1,155 views
1,071 views

Published on

Presentation explaining the most important topics about wood

Published in: Education
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,155
On SlideShare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
87
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

Wood

  1. 1. Wood Javier Gómez Calzada 1ºESO
  2. 2. What wooden objects are around us? <ul><li>At home: </li></ul><ul><li>Furniture </li></ul><ul><li>Floor </li></ul><ul><li>Doors </li></ul><ul><li>Beams </li></ul><ul><li>In Technology lab </li></ul><ul><li>Handles of tools </li></ul><ul><li>Boards of tables </li></ul><ul><li>Shelves </li></ul>
  3. 3. Why are they made of wood? <ul><li>Because it has some good properties </li></ul><ul><li>Pleasant to look at and to touch </li></ul><ul><li>Good insulator of heat </li></ul><ul><li>Strength </li></ul><ul><li>Quite rigid </li></ul><ul><li>Easy to work with it </li></ul><ul><li>It is available in most of the places </li></ul><ul><li>Very different types of wood depending on the aplication (and the money you want to spend!) </li></ul><ul><li>But it has some disadvantages too </li></ul><ul><li>Natural wood contains some natural defects (knots, rot, cracks, resin) </li></ul><ul><li>Natural wood has bad ressistance to heat and humidity (so it rots and bends) </li></ul>
  4. 4. Types of wood: Natural wood <ul><li>Hardwood </li></ul><ul><li>Trees with leaves that drop every autumn (deciduous trees) </li></ul><ul><li>Trees take a long time to grow </li></ul><ul><li>Not environmentally friendly (we use them faster than they grow!!) </li></ul><ul><li>Expensive </li></ul><ul><li>Harder than softwoods </li></ul><ul><li>Spain: Oak, elm, beech, ash </li></ul><ul><li>Non-native: mahogany, teak, ebony </li></ul><ul><li>Softwood </li></ul><ul><li>Conifers (evergreen trees) with needles </li></ul><ul><li>Trees grow faster </li></ul><ul><li>More environmentally friendly </li></ul><ul><li>Cheap </li></ul><ul><li>Softer, lighter and easier to cut than hardwoods </li></ul><ul><li>Pine, white deal, cedar, spruce, </li></ul>Depending on the structure of the tree:
  5. 5. <ul><ul><li>HARDWOODS </li></ul></ul><ul><ul><li>SOFTWOODS </li></ul></ul>Oak Elm Teak Ebony Scots pine Spruce
  6. 6. Types of wood: Manufactured wood <ul><li>More common in recent times because: </li></ul><ul><li>Lower cost </li></ul><ul><li>Lack of availability of natural wood </li></ul><ul><li>Made using different materials from natural woods: </li></ul><ul><li>Fibres or strips of wood </li></ul><ul><li>Veneers: thin layers of natural wood used to cover a manufactured wood </li></ul>
  7. 7. Manufactured wood <ul><li>MDF (medium density fibre) </li></ul><ul><li>Made from fine wood fibres glued together </li></ul><ul><li>Very strong </li></ul><ul><li>MDF dust is very fine and can damage lungs if inhaled </li></ul><ul><ul><li>Cover your mouth, nose and eyes when working with MDF!!!! </li></ul></ul><ul><li>Plywood </li></ul><ul><li>Made by sticking together several veneers </li></ul><ul><li>Flat and strong </li></ul><ul><li>It is often very thin </li></ul><ul><li>Uses: packages and boxes, drawer bottoms, … </li></ul><ul><li>Chipboard (practicle board) </li></ul><ul><li>Made by gluing and compressing together tiny pieces of wood </li></ul><ul><li>Not very strong and difficult to join </li></ul><ul><li>Can crumble and break </li></ul><ul><li>Cheap </li></ul><ul><li>Often used with a veneer facing for modern furniture </li></ul>
  8. 8. Manufactured wood <ul><li>ADVANTAGES </li></ul><ul><li>They are flat, cheap and can be strong </li></ul><ul><li>They can be cut easily </li></ul><ul><li>They do not have any knots </li></ul><ul><li>They do not rot when damp </li></ul><ul><li>Their width is not limited to the width of the tree </li></ul><ul><li>They are more environmentally friendly </li></ul><ul><li>DISADVANTAGES </li></ul><ul><li>They do not look as nice </li></ul><ul><li>They can contain a lot of chemicals </li></ul><ul><li>They may irritate the eyes and lungs </li></ul>
  9. 9. Which are the effects of using wood on the environment? <ul><li>We are using the wood faster than it grows in nature </li></ul><ul><ul><li>Loss of forests, specially in the tropics (rainforests) </li></ul></ul>Mato Grosso, Brazil, 1992 Same area in 2006 <ul><li>Loss of forests damages the planet and contributes to the global warming </li></ul>

×