 |
1. First, see if you can balance a book
on the upright edge of a flat sheet of construction
paper. What happens? |
 |
2. Next try folding the paper into a
V-shape and put the book on top. What happens now? |
 |
3. How about this: Roll the piece
of construction paper along its short side, using adhesive
or masking tape to keep it rolled into a cylinder shape
4. Now place
the book on top of the tube. What happens this time?
Is the paper tube strong enough to support the book?
|
|
5. Can you think of other ways to fold
the construction paper so that it will support something
as heavy as a book? Try different sizes of tubes,
triangular shapes, accordion folds, and I-beam shapes.
The shape of the piece of paper affects
its strength. A piece of paper is not very strong
on its own, but when it is rolled into a cylinder
or accordion shape, it becomes quite strong. This
is because the weight being placed on it is distributed
throughout the structure.
Companies that manufacture corrugated
boxes use this principle to make the material that
boxes are made of. If you look at the edge of a flap
on a shipping box, you'll see that it consists of
two flat sheets of brown paper with a layer of "wavy"
paper sandwiched in between. Each "wave" is called
a "flute," and the material is called "corrugated
board." It's what makes boxes strong enough to carry
lots of different products without being crushed.
Adapted from Paper Science,
by Harry Milgrom (Walker and Company, New York, 1978)
and Is Science Magic?, by Ovid K. Wong (Childrens
Press, Chicago, 1989).
|
