How do you harden erasers?

Answer 1

The easiest way to harden an eraser is to chill it. Because erasers are usually made from either natural (rubber) or man-made (vinyl) polymers, lowering the temperature will cause the polymer molecules to stiffen and harden the eraser.

If, however, you refer to the process of manufacturing erasers, the most common method of hardening natural rubber is vulcanization, which involves adding sulfur to natural rubber at high heat.

Answer 2

To harden erasers, you can place them in the freezer for a few hours. The cold temperature helps to firm up the eraser material, making it harder and less prone to smudging or tearing. Once the eraser has been in the freezer for the desired amount of time, you can remove it and allow it to come back to room temperature before using it.