Silly Putty

In 1943, Silly Putty was accidentally invented by James Wright, an engineer in General Electric's New Haven laboratory, which was under a government contract to create an inexpensive substitute for synthetic rubber for the war effort. By combining boric acid with silicone oil, a material resulted that would stretch and bounce farther than rubber, even at extreme temperatures. In addition, the substance would copy any newspaper or comic-book print that it touched.

There is some debate on who received the first patent. Corning Glass Works, who was also developing a substitute for rubber, applied for a patent in 1943 and received it in 1947 for treating dimethyl silicone polymer with boric oxide. Wright applied for his patent in 1944. In any event, Wright is still officially credited with the invention.

By 1945, General Electric (GE) had shared this discovery with scientists around the world, only to find that none of them, including those at the U.S. War Production Board, found it more practical than the synthetic rubber already then being produced. Several years later, an unemployed copywriter named Peter Hodgson recognized its marketing potential as a children's toy, after first seeing it advertised at a local toy store as an adult gift. Hodgson bought the production rights from GE and renamed it Silly Putty, packaging it in plastic eggs because Easter was on the way.

Though Hodgson introduced Silly Putty at the International Toy Fair in New York in February of 1950, it was not until several months later when an article appeared in The New Yorker magazine that sales took off. Initially, its market as a novelty item was 80% adult. However, by 1955 Silly Putty was most popular with kids ages six to 12 years old. Six years later, Silly Putty was introduced to the Soviet Union, followed by Europe, where it was a hit in Germany, Switzerland, the Netherlands, and Italy. By the time Hodgson died in 1976, Silly Putty had made him a multi-millionaire.

It was only after its success as a toy that practical uses were also found for Silly Putty. It picks up dirt, lint, and pet hair, and can stabilize wobbly furniture. It has also been used in stress-reduction and physical therapy (athletes have used it to strengthen their grip), and in other medical and scientific situations (like smoking cessation programs). In 1968, the Apollo 8 astronauts carried Silly Putty into space in a specially designed sterling silver egg to alleviate boredom and help fasten down tools in the weightless environment. The Columbus Zoo in Ohio has even used it to make casts of the hands and feet of gorillas for educational purposes.

The eight million units produced in 1998 is four times what was produced in 1987. Binney & Smith, the maker of Crayola products who has manufactured Silly Putty since 1977, added four fluorescent colors in 1990—magenta, orange, green, and yellow. A market study at this time showed that nearly 70% of American households had purchased Silly Putty at some time.

In 1991, "Glow in the Dark" was introduced, though classic Silly Putty has remained the best seller. Most Silly Putty is still packaged in plastic eggs. Each egg contains 0.47 oz (13.5 g) and sells for about $1.00. Binney & Smith produces more than 12,000 eggs or 300 lb (136.2 kg) each day. More than 300 million eggs—or 4,000 tons of Silly Putty—have been sold since 1950, which is enough to stretch around the earth nearly three times.

A sigma-blade mixer is used to manufacture Silly Putty. Raw materials are placed into the mixing bowl and blended together for half an hour. Once mixed, the machine operator tilts the mixing bowl and removes the material onto a cart. From there, the Silly Putty is cut and packaged.

Raw Materials

Silly Putty is made from a mixture of silicone polymers (about 70 wt%) and other chemicals, including boric acid. Powdered fillers (clay and calcium carbonate) and dry pigments (to produce color or glitter) are also added. A homemade recipe can be made from mixing together water, white glue, and borax solution.

Design

Silly putty was a serendipitous design that resulted from the combination of boric acid and silicone oil. The original design has not been significantly changed. Even the plastic eggs in which the silly putty is packaged has remained for the original marketing campaign.

The Manufacturing 

Process

The process for making Silly Putty is relatively simple and involves only a few steps. After the raw materials are checked to make sure they meet specifications, they are weighed in the appropriate amounts to make up a batch.

Mixing

1 The ingredients are placed into a large machine called a sigma blade mixer and blended together for half an hour. Once the batch is mixed, the machine operator tilts the machine and removes the sticky material onto a cart. From there, it is transported to the cutting operation.

Cutting

2 The mixed material is first cut into basketball-sized pieces by hand. These pieces are then fed into the hoppers of a machine traditionally used for pulling taffy by the candy industry that extrudes and cuts the Silly Putty into smaller pieces similar in size to a golf ball. As the pieces come out of the machine, the pieces fall onto a conveyor belt that transports them to the packaging area.

Packaging

3 There are two packaging steps. First, production workers place each piece into the plastic egg. The plastic eggs are then conveyed to a special packaging machine called a blister carding machine. This machine automatically places the egg, one per card, onto a special piece of cardboard called a blister card. Next, the machine encases the egg into a vacuum formed plastic tray.

Quality Control

A safety evaluation is conducted before manufacturing begins. At this point, the product ingredients are certified in a toxicological evaluation by the Art & Creative Materials Institute's consulting toxicologists. This certifies that the product contains no harmful or toxic materials and is then granted the AP (approved product) seal. Once this certification takes place, Silly Putty is labeled in accordance with ASTM (American Society for Testing and Materials) labeling standards.

The weight of each Silly Putty egg is controlled by sampling the extrusion process. Statistical process control is also used to maintain the correct weight. In addition to being visually checked for color, sample eggs are tested for bounce, stretch, and other performance properties.

Byproducts/Waste

What little waste is produced is recycled back into the mixing process. Since it must be safe for child's play, the material used to make Silly Putty is nontoxic.

The Future

Though Silly Putty is particularly popular with children, college students have recently taken a renewed interest. New uses will continue to be created and the artist community may find Silly Putty a medium they can't resist. At least one sculptor already is selling his creations for several thousand dollars a piece.

Silly Putty turns 50 in 2000 and a special commemorative product will be introduced. Silly Putty remains a classic toy that appeals to any age group and will continue to provide fun for many throughout the twenty-first century and beyond.