Springy materials


Most metals are springy. Steel is a common metal that can be made very springy. If a length of this steel is made into a coil it forms a spring. When a weight is hung from the spring it stretches the spring. When the weight is removed the spring pulls itself back to its original shape.



What springy materials did people sleep on before spring mattresses were invented?
In the Stone Age, people used straw and leaves. To stop thes materials moving about, they first dug pits, then filled the pits with springy branches and twigs, an finally covered these with straw, leaves and animal skins.
The Egyptians made a bed from a frame of wood with cords of flax tied across it.
The Romans invented the mattress. This was a flat bag that was filled with either straw, feather, or wool. They slept on it. Rich people had their mattresses filled with swan's down.
For centuries afterwards, mattresses were placed on hard wooden-slat beds. It was only in the early nineteenth century that the coiled spring was invented. Shortly afterwards someone had the idea of using them inside a mattress. Many mattresses still contain springs, while others contain plastic foam sheets.
Have springy materials been used for cleaning things?
Yes they have. The first brushes were made from springy twigs and sticks that were bound together at the end of a long handle. Two plants were used in particular because of their springiness and for how long they lasted: the birch tree and moorland heather. A third kind of plant - a bush called broom - also gave its name to the long handled brush. Later brushes were made from pig's skin bristles which were glued into a block of wood. Springy plastic fibres are used today for the bristles of most brushes.

Are springy materials used in sport?
Springy materials are used in a range of sports. For example, if you play table tennis you may have noticed that the bats are coated in a springy material to make the ball bounce from them more quickly.
Lawn tennis rackets have strings made from springy material. This makes the strings stretch when the ball hits them then they spring back and quickly push the ball away from the racket. The tennis ball is made from rubber and covered in felt. These springy materials make the ball bounce.


American footballers have pads which are made from springy material. They protect the players when they crash into one another. The springy material flattens when the players crash, then springs back as they move apart and so prevents the players from being badly bruised or breaking bones. Springy materials are also used to make the trampolines used in gymnastics.

What wood was used to make bows in the past?
A bow was used for many centuries for hunting and in war. It relied on two springy materials: the bow wood and the string.
The wood of the yew was used to make a bow because the branches can be bent without snapping. When the bow string is pulled back the bow is bent. When the bow string is released, the bow spring back quickly. This makes the arrow fly into the air with great speed.


Is a tyre just made of springy rubber?
No. The part we see on the outside of the tyre is the rubber mixed with carbon which gives the rubber extra strength. Inside the tyre are layers of plastic fibres which help the rubber walls stay in shape when the tyre goes over a bump. All the fibres and the rubber are held together by hoops of steel wires.