Brown, pink, and black drawing rubbers specifically designed for 2B, 4B, etc., are basically rubber rubbers. Soft, opaque when facing a strong light source. Another type of rubber commonly used in sketching is plastic rubber (soft rubber), which, as the name suggests, can freely shape shapes and is also the most flexible type in the rubber family. Not suitable for daily writing.
And the plastic erasers that are most of concern to students are actually easy to distinguish. This rubber has a strong plastic texture due to its polypropylene base. When placed under a strong light source, it will present a semi transparent state. When erasing, the rubber shavings generally do not form into strips, but rather into small or nearly granular shapes.
Of course, there are many types of erasers available on the market, with the majority being dedicated to side doors, and we won't introduce them one by one here.
Next, let's share the process of making an eraser, which involves using an eraser packaging machine/
Eraser Wrapping Machine/eraser extruder. What is the specific process?
The process of making an eraser
1. Petroleum processing plants transport powdered or liquid synthetic rubber to rubber manufacturing plants. If natural rubber is to be used, it comes in sturdy large pieces, and workers must first crush and dissolve them.
2. Mix rubber with ground pumice powder (which can make the rubber slightly harder), iron oxide (which can make the rubber pink), vegetable oil, sulfur, and other substances.
3. Heat the mixture to mix sulfur with rubber to increase its strength and make it more durable.
4. Feed the soft, still warm raw material into a stamping machine (squeezing it into a die) to make a long and thin rubber stick. Cut the rubber stick into small pieces with a knife, wait for it to cool down, and then transport it to the pencil factory to make erasers for pencils.
5. A separately used block eraser is made by injecting heated rubber mixture into various shapes of molds. After cooling down, open the mold and various shapes of erasers will come out.
