How do erasers work?
I assume you’re asking about pencil erasers, right? A pencil leaves a trail of microscopic graphite “flakes” on the paper, visible as black or grey lines to the human eye. An eraser is a soft rubber abrasive, which gently scrubs the top layer of paper, removing a little of paper together with graphite particles. Clumps of used rubber, mixed with paper and graphite are produced as the stuff you brush or blow off the paper when you’re done erasing. It’s mostly the rubber with the graphite mushed into it. There’s a little bit of the top layer of paper mixed in as well – which is why you can’t erase the same spot too much or you wear a hole in the paper.
Erasers pick up graphite particles, thus removing them from the surface of the paper. Basically, the molecules in erasers are ‘stickier’ than the paper, so when the eraser is rubbed onto the pencil mark, the graphite sticks to the eraser preferentially over the paper. Some erasers damage the top layer of the paper and remove it as well. Erasers attached to pencils absorb the graphite particles and leave a residue which needs to be brushed away. This type of eraser can remove the surface of the paper. Soft vinyl erasers are softer than the erasers attached to pencils, but are otherwise similar. Art gum erasers are made of soft, coarse rubber and are used to remove large areas of pencil marks without damaging paper. These erasers leave a lot of residue behind. Kneaded erasers resemble putty. These pliable erasers absorb graphite and charcoal without wearing away. Kneaded erasers may stick to the paper if they are too warm.
Consider the three elements; the paper, the graphite, and the eraser. The surface of the paper is comprise of ridges and bumps, microscopically. When you write on the paper, graphite is worn off the pencil tip, the graphite particles interlock with the ridges on the paper. Then comes the eraser. The eraser’s surface is something that the graphite likes to stick to more than paper. As the eraser is rubbed and worn on the page, most every graphite particle it touches has a better bond with it than the paper. The eraser “dust” that is left over is worn off eraser particles with graphite stuck to it. Ink erasers work differently. Ink penetrates the fibers of the paper and an ordinary pencil eraser does not remove the ink. Ink erasers are much harder than pencil erasers and remove ink from paper by abrading the paper fibers coated with ink and thereby removing the ink marking. http://www.fluther.
Erasers pick up graphite particles, thus removing them from the surface of the paper. Basically, the molecules in erasers are ‘stickier’ than the paper, so when the eraser is rubbed onto the pencil mark, the graphite sticks to the eraser preferentially over the paper. Some erasers damage the top layer of the paper and remove it as well. Erasers attached to pencils absorb the graphite particles and leave a residue which needs to be brushed away. This type of eraser can remove the surface of the paper. Soft vinyl erasers are softer than the erasers attached to pencils, but are otherwise similar.
