What are pencil erasers?
People also ask, what is the eraser on a pencil made of?
Erasers have a rubbery consistency and come in a variety of shapes, sizes and colours. Some pencils have an eraser on one end. Less expensive erasers are made from synthetic rubber and synthetic soy-based gum, but more expensive or specialized erasers are vinyl, plastic, or gum-like materials.
One may also ask, how long does a pencil eraser last? On average one of those white erasers lasted about three weeks. Those old red rubber ones I would lose or misplace long before wearing out.
Moreover, why do erasers get hard?
The problem with rubber erasers is that you have to "rub" for them to be effective. That requires pressure and pressure can push some graphite deeper into the paper. Also, the crystalline structure of graphite is made up of flat sheets - that's why it's used as a dry lubricant.
Why do some pencil erasers not work?
You can't really stock up on erasers because they dry out.” (This idea inspired the slogan on a t-shirt the Erasable podcast sells: “Pencil is forever.”) Advincula explained: “Over time, some of the rubber properties can be lost because of oxidation or chemical degradation.