Featured Research

from universities, journals, and other organizations

Low-tech Erasers Don't Get Rubbed Out, As Kids Go Back To School

Date:
August 5, 2003
Source:
American Chemical Society
Summary:
Dinosaurs like the manual typewriter and its annoying correction tape have long since given way to the P.C., but as kids go back to school this fall one vestige of a simpler time has survived. The trusty old eraser, with pencil or without: Where would students be if they didn't have one to help them through a math test?

Dinosaurs like the manual typewriter and its annoying correction tape have long since given way to the P.C., but as kids go back to school this fall one vestige of a simpler time has survived. The trusty old eraser, with pencil or without: Where would students be if they didn't have one to help them through a math test?

The story of the chemistry behind these under-appreciated "graphite grabbers," as some people in the industry like to call them, begins with the history of the pencil. Chemical & Engineering News, the weekly newsmagazine published by the American Chemical Society, the world's largest scientific society, reports that this history goes back to the 1560s, when people started writing with graphite sticks. The sticks later evolved into crude pencils.

C&EN notes that writers erased the first unwanted pencil marks with a ball of moist bread. Nearly 200 years later, in 1752, the French Academy of Sciences concluded that caoutchouc (condensed latex), obtained from the rubber tree, could be used to remove the marks. The first scientific description of caoutchouc had surfaced during a French geographic expedition to South Africa in 1735. In 1770, British-American chemist Joseph Priestly coined the word "rubber" to describe the product, since it was used to rub out pencil marks, the newsmagazine says.

There were two problems with the first erasers and all rubber products. First, rubber products softened during warm weather and hardened in cold weather. Second, rubber took on an unpleasant odor as it started to degrade. It took a while, but in 1839 hardware merchant-turned-chemical engineer Charles Goodyear developed the vulcanization process to cure rubber, according to C&EN.

In this process, sulfur is added to the rubber and the mixture is heated under pressure to form sulfur cross-links between the rubber's polymer chains. The cross-links increase the strength, stability and elasticity of the rubber.

After Goodyear's discovery, rubber became widely used for many items, including erasers. The first patent on a combined pencil and eraser was granted in the United States in 1858. Most pencils made outside the United States today still don't have erasers attached, however.

To make pencil erasers, cylindrical ribbons of rubber are cut into short pieces called plugs, C&EN explains. The plugs are placed in a rotating hopper that lines them up on a conveyor belt, which carries them to be joined with a pencil. A band of metal called a ferrule is glued onto the end of the pencil where a recess has been cut, while at the same time a plunger presses an eraser plug into the ferrule. When the glue dries, voila!

# # #

To access the C&EN story on erasers, which appeared in the Dec. 12, 2002, issue as part of the "What's That Stuff" series, go to: http://pubs.acs.org/cen/whatstuff/stuff/8050erasers.html


Story Source:

The above story is based on materials provided by American Chemical Society. Note: Materials may be edited for content and length.


Cite This Page:

American Chemical Society. "Low-tech Erasers Don't Get Rubbed Out, As Kids Go Back To School." ScienceDaily. ScienceDaily, 5 August 2003. <www.sciencedaily.com/releases/2003/07/030724083051.htm>.
American Chemical Society. (2003, August 5). Low-tech Erasers Don't Get Rubbed Out, As Kids Go Back To School. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2003/07/030724083051.htm
American Chemical Society. "Low-tech Erasers Don't Get Rubbed Out, As Kids Go Back To School." ScienceDaily. www.sciencedaily.com/releases/2003/07/030724083051.htm (accessed July 31, 2014).

Share This




More Matter & Energy News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
Smartphone Powered Paper Plane Debuts at Airshow

Smartphone Powered Paper Plane Debuts at Airshow

AP (July 30, 2014) Smartphone powered paper airplane that was popular on crowdfunding website KickStarter makes its debut at Wisconsin airshow (July 30) Video provided by AP
Powered by NewsLook.com
U.K. To Allow Driverless Cars On Public Roads

U.K. To Allow Driverless Cars On Public Roads

Newsy (July 30, 2014) Driverless cars could soon become a staple on U.K. city streets, as they're set to be introduced to a few cities in 2015. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins