UNITS 1 AND 2

UNITS 1 AND 2

1. Raw materials

   • Are products extracted directly from nature
     • Animals, plants and mineral
     • Air and water
     • Oil and natural gas

2. Natural and processed materials

   • Industrial processes are applied to raw materials to turn into processed materials from make more complex objects

3. The properties of wood

   • The propieties describe a material: if this is hardnes or elasticity...
   • Mechanical properties
     • Hardness
     • Mechanical resistance
     • Toughness
     • Brittleness
     • Elasticity
     • Plasticity
   • Thermal properties
     • Expansion
     • Thermal conductibility

4. Tools

   • From lots of tings the humans use the hands but from others things we can´t use our hands so we use tools
   • The first tools was very easy for example a stone with a stick but now we can´t use that because this we cannot use it because it would not serve us

5. wood andtypes of wood

   • wood
     • The wood is a fibrous material that trees are are made of.
   • Types of wood
     • Non-resinous
       • This kind of wood mainly come freom trees that have little resin and fibrous texture
     • Resinous
       • This is kind of wood usually comes from evergreen trees

6. Propertiesof wood

   • Hardness
   • Thermal and electrical inslation
   • Flexibility
   • Density
   • Sound conductibility
   • Hygroscopicity
   • Splitability
   • Toughness

7. Forms of wood

   • Natural wood
   • Prefabricated wood
   • Comercial woods

8. Wood working tools

   • Basic hand saws
   • Machine tools
   • Hammers
   • Mallets
   • Spanners
   • Screwdrivers