Can be of different colors and different densities. The softer the elastic, the more pleasant and convenient it is to use. There are special handles that can be erased with an eraser. When rubber rubs against paper with inscription, pieces of graphite are erased from the paper and stick to the surface of the rubber, which in turn is abraded (in small pieces). As a result, both the surface with the inscription (from the inscription) and the surface of the gum from the used layer are cleaned. Dried and low-quality rubber bands (in which the used layer is not erased) stain the paper, since the graphite that adheres (and does not come off with the rubber layer) is smeared on the paper.
Story.
English chemist Joseph Priestley made an amazing discovery at the beginning of the nineteenth century. It turned out that natural raw rubber could erase pencil or graphite marks better than the pieces of bread that were used for this in those days. Now “rubber” is a synonym for the word “rubber band” or “eraser”. Its first official name is eraser. Also, the name "rubber" defines the properties of raw materials (synthetic or natural rubber) used in industry for the production of rubber products, from tires to erasers.
Classification of erasers.
Rubber erasers.
There are several types of rubber-based erasers:
Erasers with a minimal content of abrasive fillers and fillers that make the eraser material more elastic; They are light in color and are designed for quick and high-quality removal of traces of graphite from the working surface. The principle of removing written lines is that the graphite sticks to the eraser and at the same time cleanses the latter by rubbing against the surface.
Erasers with a lower content of softening fillers and a small proportion of abrasives, as well as a higher percentage of other fillers and dyes. These erasers are designed for everyday use and remove traces of ordinary writing utensils.
Relatively hard erasers with a large proportion of abrasives. Emery or pumice (crushed volcanic glass) is used as abrasives. The main reason for using these materials is their ability to remove by friction the top layer of paper along with the line written in ink or ballpoint pen paste, at the same time the surface of the eraser is partially erased. These erasers must be used carefully; When erasing on low-quality paper, they can wear it down to holes.
Special erasersconsisting only of rubber and a large amount of vegetable oil, without abrasives or other fillers. Vulcanization during their production is relatively small. The result is a very sticky and easily deformed eraser. Due to the strong adhesiveness of the eraser, the weakly adherent top layer of the working surface sticks well to it. This property is used when drawing with charcoal or dry crayons.
Rubber erasers become harder over time. The hardening process is accelerated if the product is left outdoors or in the sun, so it is recommended to store rubber erasers in their packaging. If storage conditions are met, erasers retain their properties for many years.
Synthetic erasers.
This group includes erasers made of synthetic rubber, vinyl or plastic. They are sometimes called "plastic" or "plastic". They, as a rule, have a decorative shape, are available in various colors and are distinguished by the pattern printed on them - a picture.
These erasers cause virtually no static electricity, which significantly reduces the adhesion of eraser particles to the working surface. Typically, when erasing, wide, long particles separate from vinyl erasers, which reduces the number of movements, and the particles themselves are easily brushed off the work surface. Unlike rubber erasers, vinyl erasers do not deteriorate over the years.
Some types of vinyl erasers contain microcapsules with solvents, which burst during the erasing process, and the released solvent acts on the line, weakening the ink. In combination with the erasing properties of vinyl material, the solvent provides quick, clean erasing without damaging the working surface.
Mechanical erasers.
Mechanical erasers are used to permanently remove lines and marks from a working surface by using abrasives and scrapers. In such cases, it is necessary to remember that not only the lines are removed, but also part of the surface. A mechanical fiberglass eraser has a cluster of narrow glass fibers at the end, which are arranged parallel inside a sleeve that provides their rigidity. When the fibers wear out, the moving mechanism feeds a new part of the fibers. The working part of the fibers of this type of eraser should be short. This eraser is suitable for removing ink lines (of any age) and even rust stains from a car. Very abrasive and requires careful use.
2) In sewing production - dense thin cotton fabric of satin weave with a smooth shiny surface. It is used mainly for sewing women's dresses. In the past, this was the name given to lining fabric made of wool with hemp, pure wool, or silk with hemp.
Hello dears.
Last week, you and I started a new series of posts: , and I must say that you showed some interest. So, let's try to continue :-)
Well, since last time we talked about a pencil, today we’ll discuss a little about the eraser. For one thing often follows another.
By the way, it was the American Hein Lipman who first combined these two things in one in 1858. It was he who invented the pencil with an eraser at the end.
In general, an eraser is a much more necessary and convenient thing, which played a much more noticeable role in the history of civilization than is commonly thought. Well, let's say, before the advent of erasers, they used... bread crumbs to erase traces of black lead pencils.
Traditionally, I will not talk about the creation and development of erasers, but I will give you a couple of interesting (I hope) facts.
Like everyone else in childhood, I was interested in the question - how does it work. And why? Here we have physics... The eraser erases graphite due to the static electricity generated during friction. In this case, electrified graphite particles are attracted to the eraser.
If you think that erasers are rubber objects, then I want to disappoint you. Most modern erasers do not contain rubber at all, neither natural nor synthetic, but are completely polymer. Polymer erasers are no worse, because... Modern elastomers have properties in no way inferior to rubber. At the same time, they have additional useful properties.
Although, in principle, sometimes what a modern eraser is made of can be determined by its color. Red-blue or gray are made using natural rubber. Such erasers are very elastic, they can twist and stretch without deforming, but most often they do not wash very well. But pure white or multi-colored erasers are made from synthetic polymers, have good abrasiveness and are pleasant to the touch.
True, the process of their production is very labor-intensive and its violation leads to the production of erasers that are of little use for erasing, which we can often experience from our own experience. Although most often, of course, the color palette is associated primarily with the dyes included in it. For example, iron oxide or antimony sulfide is used for a red eraser, lithopone or zinc is used for a white eraser, and so on :-)
In general, the degree of softness or abrasiveness of an eraser is determined by the proportions of sulfur and additives in the rubber production process. Additional substances are added to erasers to improve erasing performance. For example, a mandatory additive is a plasticizer based on animal or vegetable oils, which is the very substance that ensures the quality of erasing.
Now modern erasers can erase felt-tip pen, ink, ink, and anything else, not just pencil. But these are modern erasers, created using modern technology. These rubber bands contain microcapsules with a solvent. Friction with paper destroys the capsule shell, activating the solvent. The released solvent weakens the dyes, and traces of ink treated with it become discolored, “disappearing” both from paper and from tracing paper or plastic.
But one of the main legends of our childhood had no basis. Remember this “eraser”:
It was believed that the red end erased the pencil, and the blue end erased the ink of the pen. This is nonsense. Those who believed in this legend rubbed notebooks and diaries to holes :-) In fact, different ends were used for different types of paper - blue for thicker ones.
If you remember the erasers that I loved, then they are probably Czech ones from the same company Koh-i-Noor Hardtmuth
The Elephant logo is one of the oldest registered trademarks in the world. The famous elephant erasers have been produced using natural rubber since 1896 to this day.
Well, in the end, I want to say that in our country several settlements are named after Eraser. 
And on April 15, the international unofficial holiday is Eraser Day.
That's it :-)
To be continued...
Have a nice time of day.
Buy some eraser clay. Ordinary clay is not suitable for such an undertaking. You need to buy clay that is specifically labeled as "eraser clay." Please note that some varieties require heating in the microwave, while others require heating in the oven. Before you get started, you should check what you need to do with a particular brand of clay.
- Clayzee eraser clay requires microwave processing, while Sculpey requires oven processing. If you are using a different brand, read the instructions on the back of the package.
- There are clay manufacturers who sell it in kits that include both clay and molds. If you didn't buy the kit, you can buy molds for your erasers separately. Any clay mold will work for you; the shapes do not need to be marked specifically for use with eraser clay.
Arrange the colors the way you want. If you're already happy with the color, you can skip this step. If you want to change the colors, now is the time.
- Mixing clay of different colors is quite simple. Pinch off portions of clay of two or more colors and combine into one ball. Roll and knead this ball until the colors are evenly combined.
Spray your ramekins with water. Use a spray bottle with warm water and gently spray the molds. This will prevent the clay from sticking.
- Water will be effective if the molds are made of plastic. If you are using ceramic molds, sprinkling a thin layer of talcum powder will be more effective.
Place the clay into the prepared molds. Place the ball of clay into the mold until it is completely filled with the mixture. If the mold has a top and a bottom, press it down on top so that the clay is distributed on the bottom.
- After opening the double-sided mold, you will notice that excess clay comes out in a thin layer along the edge of the mold. Remove this excess with your fingernail or toothpick.
Remove the clay from the mold. Gently twist and pull the finished eraser out of the mold with your hands.
You can also shape the clay with your hands. If you don't have a mold or don't want to use one, you can make any shape with your fingers.
- If necessary, you can use standard clay tools.
Hardening of clay. You will need to set the eraser's shape using heat. As discussed earlier, you will need to do this in either the microwave or oven.
- When using microwave clay, start by placing the clay in a safe container and covering it with 1/2 inch of water.
- Microwave for 2 minutes on full power using a 600-watt oven or a 1100-watt oven at 50% power.
- Drain the water and fill the container with the same amount of cold water.
- Place the clay back in the microwave for 3 minutes. Turn on a 600 W oven at full power or a 1100 W oven at 50% power.
- Remove the container from the microwave and drain the water. Let the eraser dry for several hours.
- To bake a clay eraser in the oven, start by preheating the oven to 350 degrees Fahrenheit. Place the eraser pans on a nonstick sheet, placing them far enough apart so they don't touch while baking.
- Leave the erasers to bake for 10-30 minutes, depending on the thickness. For a product with a thickness of 1.25 cm or less, only 10-15 minutes will be enough. A thick eraser will take up to 30 minutes.
- Remove the erasers from the oven and let them cool to room temperature.
The Aztecs and Mayans can easily be considered the discoverers of the eraser. Residents of South America discovered a lot of beneficial properties of white latex, which was produced by the evergreen Hevea plant. The natives called it “the weeping tree,” and the resin they secreted was called “the tears of Kaa-o-chu.” They used white latex to attach jewelry to the body and make dishes.
Eraser Milan Oval 1012 (Italy)
On April 15, 1770, Joseph Priestley - a British natural scientist, priest, philosopher, theologian, who went down in history primarily as an outstanding chemist who discovered oxygen and carbon dioxide - noted in his diary that he had discovered a material that was ideal for erasing inscriptions pencil on paper. Priestley called it "rubber". Before this, the function of an eraser was performed by... bread crumb.
By the way, in honor of this event April 15 is the international unofficial holiday Eraser Day.
Of course, pieces of rubber had to go through a long process of improvement before becoming an item of daily use. The fact is that initially this material emitted an unpleasant odor, suffered from changing weather conditions, products made from it softened in the summer and became too hard in the winter.
In 1839, American scientist Charles Goodyear mixed rubber with sulfur, which was a significant step in the evolution of the eraser. Goodyear invented the vulcanization process (named after Vulcan, the Roman god of fire), which significantly improved the quality and strength of the material obtained from natural rubber.
Nut-shaped erasers Erasers are often (especially in England) called "rubber bands". The first erasers were made only from rubber, but now only some erasers contain rubber.
Today, erasers are made from natural or synthetic or even raw rubber, plastic and vinyl.
Mechanical eraser from Japanese factory Tombow Natural rubber is obtained by coagulating and drying the sap (latex) of rubber plants (Hevea braziliensis), with polyisoprene being the main component. The rubber itself in such erasers is only a binding substance (its content in an eraser on average does not exceed 20%). By vulcanizing natural rubber, durable and elastic rubber is obtained, to which certain fillers are subsequently added.
Faber-Castell erasers (Germany) Erasers intended for removing pencil lines must be soft and of such a consistency that small pieces of them separate during erasing. Thanks to these properties, the erasing surface of the eraser is constantly replaced and updated. Since small fragments of the eraser have an adhesive structure, they easily “stick” to the particles of lead that form the line and remove them from the working surface.
Faber-Castell Fancy pencil eraser Rubber erasers become harder over time, especially if left outdoors or exposed to sunlight. Therefore, it is recommended to store them in packaging (film, parchment, special boxes). If storage conditions are followed correctly, erasers retain their properties for a long time.
Faber-Castell clamshell eraser The degree of softness or abrasiveness of an eraser is determined by the proportions of sulfur and additives in the rubber production process. Additional substances are added to erasers to improve erasing performance. For example, a mandatory additive is a plasticizer based on animal or vegetable oils, which is the very substance that ensures the quality of erasing.
Eraser Koh-i-noor (Czech Republic) Hard rubber erasers, designed for removing ink from paper, contain higher levels of abrasive additives and are designed to mechanically remove colored paper fibers. Therefore, their use requires caution, especially when working with low-quality paper: such erasers can erase it to holes!
Japanese erasers in the shape of people and animals By the way, there are erasers that can erase marks not only from a pencil or pen, but even from mascara and permanent markers! These vinyl erasers contain microcapsules containing a solvent. Friction with paper destroys the capsule shell, activating the solvent. The released solvent weakens the dyes, and traces of ink treated with it become discolored, “disappearing” both from paper and from tracing paper or plastic.
Derwent eraser (UK) Erasers made of synthetic rubber, vinyl or plastic are the next generation of erasers, which appeared in the mid-fifties and early sixties of the 20th century. They are made from soft vinyl materials containing a minimal amount of abrasives. Often, additional softeners are added to them to increase elasticity.
Faber-Castell eraser sharpener Such erasers are used to work with both paper and tracing paper or drawing film. They practically do not cause the appearance of static electricity, which significantly reduces the adhesion of eraser particles to the working surface. If, when erasing with them, the separated particles turn out to be wide and long, it means that fewer movements are required to remove lines from the paper than you are doing.
Synthetic erasers come in a wide variety of shapes and colors, often with brightly colored designs.
Faber-Castell Grip eraser cap As a rule, plastic erasers are supplied packaged in paper boxes. This is done so that the softeners they contain are not transferred to other synthetic materials upon contact. Unlike rubber erasers, vinyl erasers do not deteriorate over time.
