Hopping putty
Silly putty or Hüpfkitt is a kneaded material on silicone base with boron having content that have different consistencies depending on the application of force.
Other common names are jumping clay , jumping clay or intelligent clay .
history
During World War II , Japan occupied many areas in the South Pacific where rubber trees were very common. As a result, America suffered from a shortage of natural rubber , which it urgently needed, especially for tires and seals. The US industry therefore began looking for a natural rubber substitute.
In 1943, Earl Warrick, who had previously experimented with compounds of silicon and carbon , focused his research on developing a synthetic substitute for rubber to give the Allies an advantage in war. Although he was unable to find a suitable replacement by the end of the war, one of his research results was a jumping plasticine based on silicone.
In this day and age, hopping putty is mainly known as a toy .
Since the end of the Second World War, Crayola has been producing plasticine as a toy in the United States under the name Silly Putty . It is also sold by various manufacturers under trade names such as Bouncing Putty , Tricky Putty , Potty Putty or Thinking Putty . In Germany, the modeling clay is also known as intelligent modeling clay .
There are different types of commercially traded putty, including plasticine that changes color when heated, plasticine with shimmering effects, phosphorescent plasticine or ferromagnetic plasticine that reacts to magnets .
Physical Properties
As a so-called non - Newtonian fluid , the putty changes its viscosity when the shear forces acting on it change. Acts only a small force such. B. the gravity on the modeling clay, it slowly dissolves. However, if you form a ball and throw it against the wall, it will bounce back like a rubber ball . If the force is strong enough, for example with a hammer blow, it becomes so brittle that it splinters.
Compared to starch- based modeling clay, bouncing putty does not dry out due to its composition and does not become cracked or brittle.
Areas of application
While bouncy putty is primarily a toy, there are a few other uses for it. For example, model makers use the modeling clay as a template for airbrush painting. It should also be used as therapy clay, for example in occupational therapy or physiotherapy .
In 2014, a team of researchers from the Riverside Bourns College of Engineering at the University of California (USA) discovered that the bouncing putty can increase the energy density of lithium-ion batteries three times. In addition, the service life of the batteries could be increased. This could become important in the future for the storage of renewable energies , especially in electromobility .
Health risks
In a study published in 2005 by the Federal Institute for Risk Assessment , the boric acid content in jumping clay was assessed. Accordingly, the body is exposed to an excessive dose of boron if it comes into contact with the skin through play or misuse, for example through ingestion . This almost reaches the daily intake that the body can tolerate. Together with other recording sources such as B. food, it could be exceeded. How much of the boric acid is actually released and absorbed by the body could not be simulated or determined.
Web links
- Hopping putty. University of Munich, Laboratory for Physics and Didactics.
Individual evidence
- ^ Sepp Kressierer: Hopping putty. Brief description. In: av.ph.tum.de. Technical University of Munich - Physics Department, 2011, accessed on December 10, 2019 .
- ↑ What is this stuff? Where did it come from? (No longer available online.) In: puttyworld.com. Crazy Aaron Enterprises, Inc., archived from the original on November 2, 2011 ; accessed on October 6, 2011 .
- ↑ Intelligent clay as therapy clay. In: knete.de. Trendbuzz GmbH, accessed on December 10, 2019 .
- ↑ Thomas Scherer: Hopping putty increases the energy density of Li-Ion batteries. In: elektormagazine.de. Elektor Verlag GmbH, May 22, 2014, accessed December 10, 2019 .
- ↑ Zachary Favors, Wei Wang, Hamed Hosseini Bay, Aaron George, Mihrimah Ozkan & Cengiz S. Ozkan: Stable Cycling of SiO2 Nanotubes as High-Performance Anodes for Lithium-Ion Batteries. In: Nature Scientific Reports. Nature Research, April 15, 2014, accessed December 10, 2019 .
- ↑ Boric acid in jumping clay - Health assessment No. 014/2005. (PDF; 48.8 KiB) In: bfr.bund.de. Federal Institute for Risk Assessment, October 27, 2004, pp. 1–5 , accessed on December 10, 2019 .