Although static electricity can be a
nuisance--like getting shock when you tough a doorknob
or static cling on your clothes--it has a number of
beneficial uses. The forces of attraction caused by
static electricty are used in air pollution control,
automobile painting, and xerography or copy machines.
Being curious, questions you may have
are:
-
How can static electricity stop
smoke stack pollution?
-
What happens to freshen the air?
-
How does a Xerox machine work?
Pollution control
By charging dirt particles in the air
with a static charge, they can be made to be collected,
thus acting as an effective air pollution control. They
are often called electrostatic precipitators.
Factories use static electricity to
reduce pollution coming from their smokestacks. They
give the smoke an electric charge. When it passes by an
electrode of the opposite charge, most of the smoke
particles cling to the electrode. This keeps the
pollution from going out into the atmosphere.
Some people purchase what are called air
ionizers to freshen and purify the air in their homes.
They work on a similar principle as the smokestack
pollution control. These devices strip electrons from
smoke molecules, dust particles, and pollen in the air,
just as what happens in creating static electricity.
These charged dust and smoke particles
are then attracted to and stick to a plate on the device
with the opposite charge. After a while, much of the
pollution is drawn from the air.
Since charged particles will also stick
to neutral surfaces, some of them can stick to the wall
near the ionizer, making it very dirty and difficult to
clean.
Your photocopier or Xerox machine uses
static electricity to copy print to a page. This is done
through the science of xerography.
One version gives ink an electrical
charge so that it will stick to the paper in the
designated areas. Another version of a photocopier uses
charges to stick the ink to a drum, which then transfers
it to the paper.
Some automobile manufacturers use static
electricity to help them paint the cars they make. The
way this works is first they prepare the car's surface
and put it in a paint booth, next they give the paint an
electrical charge, and then they spray a fine mist of
paint into the booth.
The charged paint particles are
attracted to the car and stick to the body, just like a
charged balloon sticks to a wall. Once the paint dries,
it sticks much better to the car and is smoother because
it is evenly distributed.
Uses of static electricity include
pollution control, Xerox machines, and painting. Can you
think of any other uses for static electricity? Think of
its properties of attraction, repulsion and causing
sparks. Perhaps you can come up with a new use or
invention that will help solve some problems that people
have. |