silly string
DESCRIPTION
Silly String . By: Valentina Caval And Wajeeha Jafferalli. The History of Silly String. Silly String was invented by Leonard A. Fish and Robert P. Cox A patent was issued in 1972 for foamable resinous composition Originally it was named as :“squibbly.”. Composition. - PowerPoint PPT PresentationTRANSCRIPT
By: Valentina CavalAnd
Wajeeha Jafferalli
SILLY STRING
THE HISTORY OF SILLY STRING
• Silly String was invented by Leonard A. Fish and Robert P. Cox
• A patent was issued in 1972 for foamable resinous composition
• Originally it was • named as :“squibbly.”
Composition• A resin forms the plastic structure of the strand. The original
formula used polyisobutyl methacrylate— an acrylic resin. • A surfactant—or surface-active agent—helps the resin foam
and modifies the stickiness of the strands. • Propellant: 75% liquid in the can : forces the other ingredients out of the aerosol can, and causes them to foam and helps form the skin. The propellant described in the patent is Freon-12. • The Silly String manufactured today uses
other propellants –Freon-12 is an ozone depleting substance that is no longer manufactured.
ELEMENTS IN SILLY STRING
Dibutyl phthalate makes it sticky to the touch.
Silicone fluids such as dimethyl siloxane make the finished streamers easier to peel away from most targets.
A bit of solvent such as dichloromethane keeps everything as a one-phase mixture.
dimethyl siloxane dichloromethaneDibutyl phthalate
Chemical Structures
How does it work?At normal air pressure the propellant in Silly String would be a gas. The high pressure inside the can
keeps it in its liquid state. When you press the nozzle,
a valve opens inside the can, giving the highly
compressed liquid a chance to escape. Liquid rapidly
moves up the tube inside the can, and travels from the
high-pressure environment inside to the lower-pressure
environment outside. Outside of the can, the
liquid propellant becomes a gas, causing the remaining
ingredients to foam.
Silly String Yesteryear:• It was used by American
and British forces to detect tripwires for explosive booby traps.
• The soldier would stand in the doorway and spray the material over the suspect area. If the string fell to the ground there were no tripwires. However, if there was a tripwire, the string would be suspended in the air without pulling the wire
• They can not use silly string in the current war because you cant ship aerosol over seas
Silly String Today:
• Family Games• Parties: surprise welcome home graduation weddings• Child activities
Is Silly String dangerous?
• Its large proportion of propellant can also give Silly String two seemingly opposite safety hazards:
• Some propellants are flammable, and others become so cold when leaving the container that they can freeze a person's skin.
Interesting Facts• Silly string can clog storm drains and
take up space in landfills.
• Silly String is banned in Hollywood on Halloween night : If you are
caught with silly string you could be faced with a $1,000 fine!
For your Entertainment:http://www.youtube.com/watch?v=UWIsnpsAfSs
Bibliographyhttp://www.youtube.com/watch?v=w8efguf0XOs&feature=related
http://entertainment.howstuffworks.com/silly-string1.htm
http://gizmodo.com/294660/silly-string-rifle-makes-war-games-sillier
http://commons.wikimedia.org/wiki/File:Mgm_Silly_string_roadsign.jpg
http://www.aviary.com/artists/mpeutz/creations/seriouslyjanes_silly_string
http://www.drinkstuff.com/products/product.asp?ID=978