Styrofoam is usually used as daily food containers, securing an object of a direct collision, also used as an advertising tool.
Styrofoam often used because it is easy to be formed into a variety of shapes. Styrofoam also has a very light weight making it easy to float in water. in our body, styrofoam almost every day stick very close to our heads. it is a helmet. helmet also contains styrofoam to absorb shocks during impact.
For the use of Styrofoam in advertising, usually can be seen on greeting board made of flowers and letters made of styrofoam. Many shape of letters and symbols can be made using styrofoam materials, as styrofoam easy to cut .
When I was a kid, I build a small boat made of styrofoam. The thickness of styrofoam that I use to make the boat there were about 4cm. At that time, to cut styrofoam I use a knife and sandpaper so that the cutting should be done slowly because using a knife to cut styrofoam is very difficult.
Greeting flower sellers usually cut styrofoam using special cutting tools, the device is shaped like a hack saw, but the saw blade is replaced with a thin wire that if given voltage will generate heat. The hot wire is used to form styrofoam in accordance with the order.
like the picture presented above, the letters with many shapes easily be made by the makers of flowers greeting as styrofoam easily melt if exposed to heat. Usually the styrofoam seller cutting the styrofoam by using the guitar strings with voltage to produce heat.
But after investigation, a guitar string has very little resistance , so it will require a large electric current to produce heat. Then I use objects that are more energy efficient to produce heat. The object is a solder element.
On experiments that I have done, the value of voltage that I use to generate heat from 40cm wire solder element is only 15 volts. The electric current required by the wire to produce heat only about 400mA. It is a value that is very small and very energy efficient for a simple styrofoam cutting tools.
You can see the video of my experiment below. Styrofoam can be cut off completely without any damage.