How It Works
All brands of confetti string work the same way--a liquid mixed with a polymer resin is stored inside a can. Pigment provides color and polyisobutyl methacrylate (or similar type molecules) prevent the string from catching aflame once it's sprayed. Plasticizers like dibutyl phthalate give the string strength and stickiness without weighing it down. Silly String also contains propellant which send it flying dozens of feet from the user's hand. When the button on the can (or trigger on a Silly String "gun") is depressed, a colorful strand of sticky string flies into the air, landing on anything in its path.
Silly String Uses
Silly String is most commonly used for celebrating at New Year's Eve parties and at other events like weddings. Young adults sometimes use it to prank friends by spraying it all over a friend's bedroom or house and the product can also be used to decorate for occasions like Halloween. Silly String also has serious uses though; researchers want to use it as an adhesive in medical situations. American soldiers use the string to detect trip wires on bombs in Iraq and Afghanistan.
Cleaning It Up
The dimethyl siloxane within Silly String and other brands of confetti or party string make it easy to peel away from most surfaces. Pick or peel it off of surfaces while it is still wet, especially if it's landed on clothing. Once dried, scrape away with fingernails. For stubborn dried string, aerosolized metal lubricant can help loosen its grip on plastic or rubber surfaces. If it lands in your hair, wash and rinse thoroughly to remove.
Environmental Concerns
When Silly String was originally patented in the 1970s, the propellant used was CFC-12 or cholorofluorocarbon, which has since been banned in the United States and other countries because it depletes the earth's ozone layer. While CFC-12 is banned, manufacturers, including the brand name Silly String, use safe propellants to launch their stringy products. Occasionally, a company will get fined by the EPA for using an unsafe propellant, like Tween Brands was, and will be ordered to remove its product from store shelves.