How is the eraser made?

There are natural polymers and synthetic polymers, mainly some organic polymers formed by addition polymerization. \x0d\x0d\ Long ago, people used bread to erase pencil words. /kloc-in 0/700, an English scientist invented the eraser. After continuous improvement, today's eraser can easily erase lead \x0d\ handwriting, and it will not stain the paper, and the eraser itself is clean. \ x0d \ is because the powder of the refill enters the gap of the paper. When we write a pencil with an eraser, the crumbs falling from the eraser can stick the pencil powder down and wrap it up. These powders can't stay in the gaps of the paper, so they have to run out, and the handwriting disappears, leaving only some rubber residue on the paper. \x0d\ Because the ink permeates the fibers of the paper, words written with wax sticks cannot be erased with an eraser because they contain slippery wax. Pencil lead is made of graphite and clay. Graphite is soft, black and easy to attach to paper, so you can write. Rubber is very soft, with high friction and certain viscosity. If you wipe it on paper, you can stick the written words off without damaging the paper, so that you can erase the pencil words with an eraser. If you write with a ballpoint pen, the ink will penetrate into the paper and will not be easily erased. \ x0d \ x0d \ 1770, British scientist joseph priestley said, "I saw a substance that is very suitable for erasing pencil handwriting. \ x0d \ x0d \ At that time, Europe used rubber particles cut into small cubes to erase handwriting. This substance is called an eraser. \x0d\\x0d\ Edward Naime, another British engineer, is regarded as the inventor of the eraser in 1770. Before that, people used bread crumbs to erase handwriting. Naimei said that once he accidentally picked up a rubber as bread crumbs, but found that the effect was very good, so he began to produce and sell rubber. \x0d\\x0d\ The initial eraser was inconvenient because the raw rubber was easy to rot. It was not until 1839 that the inventor Charles Goodyear discovered that vulcanization could improve the quality of rubber, and the eraser became reliable. \ x0d \ x0d \ 1858 A man in Philadelphia, USA, obtained a patent for embedding an eraser at the end of a pencil, but the patent for this pencil with an eraser was later revoked because it was judged as "just embedding two existing things together, not a new product". \x0d\\x0d\ English name of eraser \x0d\ In Britain and Australia, eraser is called eraser; ; But in America, rubber is one of the common names of condoms, and the name of eraser is eraser. This difference is often regarded as a joke by Americans. \x0d\ There are many kinds of erasers to meet different needs. \ x0d \ x0d \ Some pencils have a small eraser at the end. Most of these erasers are pink and the surface is smooth gum. They perform well on most occasions, but sometimes they get stuck on paper. If you push too hard, the eraser still has a chance to break the paper. When erasing handwriting, the eraser will leave a residue on the paper. If it is not cleaned properly, these residues will leave marks on the paper. \x0d\\x0d\ Another eraser is a brown eraser commonly used by artists, which is made of soft and rough rubber. Its design is easy to erase large areas of traces without damaging the paper. But this eraser can't erase handwriting effectively and accurately. \x0d\\x0d\ Another eraser commonly used by artists is called soft eraser. It is mainly made of a gray material and rubber with gum. Its strength makes it leave no residue, so its life is longer than other erasers. It eliminates handwriting by "absorbing" graphite. This eraser can not only erase the handwriting (in fact, it can accurately remove the handwriting), but also be used to highlight important parts or make the work more detailed. But it is not good at removing large areas of handwriting, and it will get dirty or even stick to paper if it is overheated. \x0d\\x0d\ Soft polyethylene eraser has plastic texture and has the same function as ordinary pink eraser. These erasers are softer than pink erasers, so they are unlikely to damage the paper. Polyethylene erasers are usually white