Eraser

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Innovation Info
Year Invented: 
1770
Image Credit: 
iwakousa.com
Main Image: 

Eco friendly erasers are made in Japan.  They do not have lead, pthalates or paint. And it is recyclable. A company named Iwako in Japan makes eco friendly erasers. Before the eraser was invented  wax, or even bread, was used to erase pencil marks.

What is the invention history of Eraser?

In 1770 Edward Nairne, a British Engineer manufactured the first rubber eraser. But it was  John Priestly who first wrote about the rubber eraser. So John Priestly seems to be the inventor of the eraser. Before the eraser was invented people used bread and wax to remove pencil marks. In 1735, it was a French  scientist Charles de la Condamine, who found people in South America playing with rubber which they used as bouncy balls and to glue feathers together for their headdress. They called it Caoutchouc.  It was made from a fluid produced under the bark of a tree found in tropical areas . This milky liquid is  known as latex, and is used to make natural rubber. John Priestly name this "rubber"  because it rubbed away the pencil marks.

 

In 1858, Hyman Lipman of Philadelphia made a pencil with a groove into which an eraser was glued. He patented his idea in early 1860s, the Faber company made pencils with attached erasers

 

How  are Erasers made?

The raw material used to make an eraser is natural or synthetic rubber. While natural rubber comes from latex of the rubber tree Hevea brasiliensis, synthetic rubber is made from chemicals like styrene and butadiene. To the rubber are also added sulfur,vegetable oil and pumice and pigments. When making erasers with natural rubber , water is removed from the latex, this increases the  rubber content to 60%. Acid is added to the liquid concentrate  to produce solid sheets of dry rubber. Pigments such as iron oxide, zinc oxide are added to the rubber to get different colored erasers. In 1839 Charles Goodyear added sulfur to rubber to vulcanize it . This process makes rubber more durable. 
 

What are the uses of uses of Eraser?

  • Mostly used for taking away pencil marks
  • Recently developed erasers take out certain types of ink marks
  • Erasers are also used to take off marks from wood, glass, or fabrics