The Composition of Erasers
Erasers are not made from a single chemical formula, but rather a combination of materials. The specific formula varies depending on the type of eraser and its intended use. However, most erasers share some common ingredients:
- Elastomer: This forms the base of the eraser and provides its flexibility and ability to rub against surfaces. Common elastomers used include polymers like polyvinyl chloride (PVC), styrene-butadiene rubber (SBR), natural rubber, or synthetic rubber.
- Fillers: These are added to improve the erasing performance and durability of the eraser. Common fillers include calcium carbonate, silica, and titanium dioxide.
- Plasticizers: These help to make the eraser more pliable and less brittle. Common plasticizers include phthalates, adipates, and citrates.
- Pigments: These are added to give the eraser its color.
- Additives: These can include antioxidants, lubricants, and anti-static agents.
Different Types of Erasers
- Soft Erasers: These are typically made from polyvinyl chloride (PVC) and are good for erasing pencil marks on paper.
- Hard Erasers: These are typically made from styrene-butadiene rubber (SBR) and are good for erasing ink and other permanent marks.
- Kneaded Erasers: These are made from a mixture of polymers and fillers, and they can be molded and shaped to erase specific areas.
Examples of Eraser Formulas
- Soft Eraser Formula: PVC, calcium carbonate, phthalates, titanium dioxide, and pigments.
- Hard Eraser Formula: SBR, silica, adipates, pigments, and antioxidants.
