Silly String (generically known as aerosol string) is a toy of flexible, sometimes brightly colored, plastic string propelled as a stream of liquid from an aerosol can. The solvent in the string quickly evaporates in mid-air, creating a continuous strand. Silly String is often used during weddings, birthday parties, carnivals and other festive occasions, and has also been used by the US military to detect tripwires.
Silly String is made of a mixture of components dispersed throughout a liquid solvent in the product’s aerosol can. These substances include a polymer resin that provides the string’s structure, a plasticizer to tune the physical properties of the string, and a surfactant that promotes foaming of the product. Other ingredients include silicone fluid (to make the strands easier to clean up), flame retardant, and a pigment for color. [1]
A key component in Silly String is its aerosol spray can and the propellant that ejects the product mixture from the can. The product originally used chlorofluorocarbon propellant Freon 12 mixed with Freon 11, both part of a group of compounds that damage the ozone layer. In 1978, the United States banned the use of CFCs like Freon 11 and 12 in aerosol cans. The manufacturers then changed the formulation to use permitted propellants. [2] Aerosol propellants are liquids with very low boiling points. When under pressure inside the can, the propellant is in liquid form, but when the nozzle is opened, it rapidly escapes – along with the compounds mixed in it – and evaporates as it enters the air. The string takes shape as the propellant evaporates.
The product forms a string that holds itself together while remaining slightly sticky to the touch. This allows the product to weakly adhere to people and windows, for instance, but easily be cleaned up without the string falling apart or staining inert surfaces. [1]
The current formulation is not published, but one of the primary recipes in the original patent calls for 12.2% of the synthetic resin poly(isobutyl methacrylate) by weight. It additionally calls for 0.5% of the selected plasticizer, dibutyl phthalate, 2.5% of sorbitan trioleate surfactant, 0.35% silicon fluid such as dimethyl siloxane or methyl phenyl siloxane, 5.6% of flame retardant hexabromobenzene, and 2–3% pigment (all percentages by weight). The aerosol propellant represents the bulk of the product. Solubility of the resin and other materials in the product is enhanced by addition of another solvent, originally Freon 11, in 6.6% by weight. [1]
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The invention of the original silly string was accidental. In 1972, a United States Patent was issued to Leonard A. Fish, an inventor, and Robert P. Cox, a chemist, for a "foamable resinous composition". The partners initially wanted to create a can of aerosol that one would be able to spray on a broken/sprained leg or arm and use as an instant cast. Their invention worked, but the pair had to test 500 different types of nozzles. After testing about 30 or 40, Fish came upon one that produced a nice string, which shot about 30 feet across the room. This incident inspired Fish to turn the product into a toy. After altering the formula to be less sticky and adding colors, the pair decided to market their product.
Because neither of them knew how to sell toys, they made an appointment with Wham-O. Fish described how, during that meeting, he sprayed the can all over the person he was meeting with and all over his office. This person became very upset and asked him to leave the premises. One day later, Fish received a telegram asking him to send 24 cans of "Squibbly" for a market test immediately, signed by the same individual who had kicked him out. He called them back and explained that, after he had finished cleaning up his office, the two owners of Wham-O had come back to talk to him, and one had noticed a piece of the string on a lamp shade he had overlooked while cleaning up. He explained where the string came from and the owners quickly asked him to send samples over for a market test. Two weeks later, Wham-O signed a contract with Fish and Cox to license the product, now known as Silly String.
Silly String was licensed to and produced by Wham-O, in a range of colors including blue, red and green, until the Car-Freshner Corporation, the maker of Little Trees, acquired the Silly String trademark in 1997. Silly String Products, a division of Car-Freshner Corporation, manufactures Silly String in the United States and distributes Silly String in North America. The U.S. Patent #3705669 includes a description of preferred implementations. [3] Similar toys are Goofy String, Streamer String, Wacky String, and Nickelodeon Smatter.
In December 2006, Tween Brands Inc., a retailer of girls' clothing and accessories in the United States, was fined $109,800 by the United States Environmental Protection Agency for "allegedly distributing canned confetti string damaging to the ozone". EPA said that the product marketed under various names by the retailer damages the stratospheric ozone layer. The production and use of chemicals harmful to that layer is controlled by U.S. federal law. [4]
Silly String and similar products have been used by the military to detect tripwires for explosive booby traps. The string is sprayed in the air over the area, revealing hidden tripwires by catching on them as it falls. The string is light enough that it does not break the wires and trigger the explosive. [5] [6] [7]
The military applications of Silly String were first discovered by Sergeant First Class David B. Chandler, Chief Instructor of the United States Army's Sapper Leader Course, in 1993. In 2006, it was being used by U.S. troops during the Iraq War for tripwire detection. [8] [9] [10] However, because the material is an aerosol, it could not be shipped privately to Iraq and is not provided by official channels. Thus, 80,000 cans were unintentionally stockpiled in New Jersey. [11] In October 2007, a shipping company with the required credentials was able to send the silly string overseas. [12]
The use of aerosol string products has been banned in several places for various reasons, including cleanup and removal costs and fears of potential damage to house or vehicle paint.
It has been banned in the city of Ridgewood, New Jersey, and a number of other places, and also at some public gatherings and events. [13] The town board of Huntington on Long Island banned the sale of Silly String within 1,500 feet (460 m) of the route of a parade. [14] [15] In 2001, the town of Middleborough, Massachusetts, banned Silly String; offenders face a $300 fine. [16]
In 2004, Los Angeles enacted a city ordinance (LAMC Section 56.02) to ban aerosol string in Hollywood on Halloween night. [17] [18]
Inhalants are a broad range of household and industrial chemicals whose volatile vapors or pressurized gases can be concentrated and breathed in via the nose or mouth to produce intoxication, in a manner not intended by the manufacturer. They are inhaled at room temperature through volatilization or from a pressurized container, and do not include drugs that are sniffed after burning or heating. For example, amyl nitrite (poppers), gasoline, nitrous oxide and toluene – a solvent widely used in contact cement, permanent markers, and certain types of glue – are considered inhalants, but smoking tobacco, cannabis, and crack cocaine are not, even though these drugs are inhaled as smoke or vapor.
Paint is a material or mixture that, when applied to a solid material and allowed to dry, adds a film-like layer. As art, this is used to create an image or images known as a painting. Paint can be made in many colors and types. Most paints are either oil-based or water-based, and each has distinct characteristics.
Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are fully or partly halogenated hydrocarbons that contain carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F), produced as volatile derivatives of methane, ethane, and propane.
Varnish is a clear transparent hard protective coating or film. It is not to be confused with wood stain. It usually has a yellowish shade due to the manufacturing process and materials used, but it may also be pigmented as desired. It is sold commercially in various shades.
Freon is a registered trademark of the Chemours Company and generic descriptor for a number of halocarbon products. They are stable, nonflammable, low toxicity gases or liquids which have generally been used as refrigerants and as aerosol propellants. These include chlorofluorocarbons and hydrofluorocarbons, both of which cause ozone depletion and contribute to global warming. 'Freon' is the brand name for the refrigerants R-12, R-13B1, R-22, R-410A, R-502, and R-503 manufactured by The Chemours Company, and so is not used to label all refrigerants of this type. They emit a strong smell similar to acetone. Freon has been found to cause damage to human health when inhaled in large amounts. Studies have been conducted in the pursuit to find beneficial reuses for gases under the Freon umbrella as an alternative to disposal of the gas.
A propellant is a mass that is expelled or expanded in such a way as to create a thrust or another motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the engine that expels the propellant is called a reaction engine. Although technically a propellant is the reaction mass used to create thrust, the term "propellant" is often used to describe a substance which contains both the reaction mass and the fuel that holds the energy used to accelerate the reaction mass. For example, the term "propellant" is often used in chemical rocket design to describe a combined fuel/propellant, although the propellants should not be confused with the fuel that is used by an engine to produce the energy that expels the propellant. Even though the byproducts of substances used as fuel are also often used as a reaction mass to create the thrust, such as with a chemical rocket engine, propellant and fuel are two distinct concepts.
Aerosol spray is a type of dispensing system which creates an aerosol mist of liquid particles. It comprises a can or bottle that contains a payload, and a propellant under pressure. When the container's valve is opened, the payload is forced out of a small opening and emerges as an aerosol or mist.
Halomethane compounds are derivatives of methane with one or more of the hydrogen atoms replaced with halogen atoms. Halomethanes are both naturally occurring, especially in marine environments, and human-made, most notably as refrigerants, solvents, propellants, and fumigants. Many, including the chlorofluorocarbons, have attracted wide attention because they become active when exposed to ultraviolet light found at high altitudes and destroy the Earth's protective ozone layer.
Air fresheners are products designed to reduce unwanted odors in indoor spaces, or to introduce pleasant fragrances, or both. They typically emit fragrance to mask odors, but may use other methods of action such as absorbing, bonding to, or chemically altering compounds in the air that produce smells, killing organisms that produce smells, or disrupting the sense of smell to reduce perception of unpleasant smells.
Polydimethylsiloxane (PDMS), also known as dimethylpolysiloxane or dimethicone, is a silicone polymer with a wide variety of uses, from cosmetics to industrial lubrication and passive daytime radiative cooling.
Shaving cream or shave cream is a category of cream cosmetics used for shaving preparation. The purpose of shaving cream is to soften the hair by providing lubrication.
Drano is an American brand of chemical drain cleaner that is manufactured by S. C. Johnson & Son.
Dichlorodifluoromethane (R-12) is a colorless gas usually sold under the brand name Freon-12, and a chlorofluorocarbon halomethane (CFC) used as a refrigerant and aerosol spray propellant. In compliance with the Montreal Protocol, its manufacture was banned in developed countries in 1996, and in developing countries in 2010 out of concerns about its damaging effect on the ozone layer. Its only allowed usage is as a fire retardant in submarines and aircraft. It is soluble in many organic solvents. R-12 cylinders are colored white.
1,1,1,2-Tetrafluoroethane (also known as norflurane (INN), R-134a, Klea 134a, Freon 134a, Forane 134a, Genetron 134a, Green Gas, Florasol 134a, Suva 134a, HFA-134a, or HFC-134a) is a hydrofluorocarbon (HFC) and haloalkane refrigerant with thermodynamic properties similar to R-12 (dichlorodifluoromethane) but with insignificant ozone depletion potential and a lower 100-year global warming potential (1,430, compared to R-12's GWP of 10,900). It has the formula CF3CH2F and a boiling point of −26.3 °C (−15.34 °F) at atmospheric pressure. R-134a cylinders are colored light blue. A phaseout and transition to HFO-1234yf and other refrigerants, with GWPs similar to CO2, began in 2012 within the automotive market.
Hair spray is a common cosmetic hairstyling product that is sprayed onto hair to protect against humidity and wind and have it stay in a desired shape. Hair sprays typically consist of several components for the hair as well as a propellant.
Spray paint is paint that comes in a sealed, pressurized container and is released in an aerosol spray when a valve button is depressed. The propellant is what the container of pressurized gas is called. When the pressure holding the gas is released through the valve, the aerosol paint releases as a fine spray. Aerosol painting is one form of spray painting; it leaves a smooth, even coat, unlike many traditional rolled and brushed paints. Aerosol primer can be applied directly to bare metal and many plastics.
A gas duster, also known as tinned wind or compressed air, is a product used for cleaning or dusting electronic equipment and other sensitive devices that cannot be cleaned using water.
Cleaning agents or hard-surface cleaners are substances used to remove dirt, including dust, stains, foul odors, and clutter on surfaces. Purposes of cleaning agents include health, beauty, removing offensive odor, and avoiding the spread of dirt and contaminants to oneself and others. Some cleaning agents can kill bacteria and clean at the same time. Others, called degreasers, contain organic solvents to help dissolve oils and fats.
Hairstyle products are used to change the texture and/or shape of hair.
Dry shampoo otherwise known as hybrid shampoo is a type of shampoo which reduces hair greasiness without the need for water. It is in powder form and is typically administered from an aerosol can. Dry shampoo is often based on corn starch or rice starch. In addition to cleansing hair, it can also be used as a tool for hair-styling as it can create volume, help tease hair, keep bobby pins in place, and be used in place of mousse in wet hair. Dry shampoo proponents attest that daily wash-and-rinse with detergent shampoo can strip away natural oils from hair. However, others attest that spraying dry shampoo every day will lead to a build-up of product that can dull hair color and irritate the scalp, arguing that the scalp needs regular cleansing and exfoliating to get rid of bacteria, remove dead skin cells, and stay healthy.