1. Wood
Name 5 objects that are made out of wood. Is the same TYPE of wood used in all of these objects? If not, how does the wood differ?
What types of trees are used to make wood? What part of a tree is used to manufacture wood?
What mechanical properties does wood possess? What factors can effect the mechanical properties of wood?
Why is wood a commonly used material in the manufacture of technical objects?
What is modified wood made of and what is the advantage of using this material over natural wood?

2. Wood Terminology Hard wood—Soft woods
All native species of trees are divided into two classes.
Hard wood have broad leaves and are deciduous
ex: Maple, yellow birch, oak
Soft woods are conifers
ex: spruce, pine, cedar

3. Materials obtained from trees come from…
Sap wood
Bark
Sapwood: the outer portion that conducts sap and has the living cells.
Heartwood : the inactive cells in the inner portion.
Mineral deposits may cause darker color.
Deposits make wood more durable.
Heart wood
Tree roots, branches and bark have little to no commercial value

4. Wood Terminology--cont. Growth rings
Summerwood
Because the rate a tree grows change with the seasons, a cross section will show distinctive rings.
Springwood
Inner part of the growth ring
Usually larger cavities and thin walls
Summerwood
Outer part of growth ring
Smaller cells and thicker walls.
A tree grows one springwood and one summerwood ring each year.
Used to age trees
Springwood

5. Wood Terminology--cont. Sawing Direction
Plain sawn (Flat sawn)
Board is sawed “parallel” to growth rings
Most common boards.
Quarter sawn
Log is first quartered
Boards are cut “perpendicular” to the grain.
Usually must be special ordered.
Were have you seen quarter sawn boards used?

12. What factors can effect the mechanical properties of wood?
Why is wood a commonly used material in the manufacture of technical objects?

13. 5) What is modified wood made out of?
Modified wood is treated wood or material made with wood mixed with other substances such as glue, plastics or preservatives.

14. p. 377

15. Treated Wood

16. Laminated Wood

17. Plywood

18. Particle Board

19. Fiberboard

20. 5) What is the advantage of using this modified wood over natural wood?