Some popularization of knowledge of rubber products
There are many different kinds of raw materials in rubber products, but they all fall into two broad categories:
Natural rubber (vegetable latex) and synthetic rubber (manufactured in chemical factories or laboratories).
Commercially, the most important synthetic rubbers are styrene butadiene (SBR), polyacrylic and polyvinyl acetate (PVA);
Other types include polyvinyl chloride (PVC), polychloroprene (commonly known as neoprene), and various types of polyurethane.
While natural rubber and synthetic rubber are similar in some respects, they are made by completely different processes and are chemically completely different.
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natural rubber
Natural rubber is made from a runny, milky liquid called latex that oozes out of certain plants when you cut into them.
Common dandelions, for example, produce latex; if you snap off their stems, you can see latex dripping off them.
In theory, there is no reason why we can't make rubber by growing dandelions, although there are more than 200 kinds of plants in the world that can be used to produce latex, more than 99 percent of the natural rubber in the world is produced by a tree called Hevea brasiliensis Made of latex made from tree species.
The latex is about one-third water, and one-third rubber particles, in a form known as a colloidal suspension. Natural rubber is a polymer of isoprene (also known as 2-methyl-1,3-butadiene) and has the chemical formula (C5H8)n.
More simply, it consists of thousands of basic C5H8 units (isoprene monomers) loosely linked to form long, tangled chains.
These molecular chains can be pulled apart fairly easily, but if you release them, they just snap back - that's what makes the rubber elastic.
synthetic rubber
Synthetic rubber is refined using petrochemicals in chemical plants.
The first, and most famous, is: Neoprene (the trade name for polychloroprene), which is made by reacting acetylene and hydrochloric acid.
Another synthetic rubber: Emulsion Styrene Butadiene Rubber (E-SBR) is widely used in the manufacture of vehicle tires.
This article focuses on natural rubber.
Rubber shock pad
How is rubber made?
The production of rubber products from natural rubber requires several different steps.
1. First, latex must be collected from rubber trees using a traditional process called rubber tapping.
This involves making wide V-shaped cuts in the bark of the tree. As the latex drips out, it is collected in a cup.
2. The latex from many trees is then filtered, washed and reacted with acid to cause the rubber particles to coagulate (stick together).
The rubber made in this way is pressed into thick sheets or thin sheets and then dried in preparation for the next stage of production.
Plus, when it gets cold, it tends to get cold, smelly, sticky, sticky.
Further processing follows to turn it into a more versatile material.
3. A mechanical process first known as a "chewing machine" that uses mechanical rollers and pressure to "chew" raw rubber to make it softer, easier to handle, and stickier.
After the rubber has been masticated, additional chemicals are mixed in to improve its properties (for example, to make it more wear-resistant).
4. Next, the rubber is flattened by rollers (a process called calendering), or extruded through specially shaped holes to make a hollow tube (a process called extrusion).
5. Finally, the rubber is vulcanized (cooked): sulfur is added and the rubber is heated to about 140 degree (280 degree F) in an autoclave (an industrial pressure cooker).
shock absorbing cover
Where does rubber come from?
The rubber tree Hevea brasiliensis, as its name suggests, originally came from Brazil, but was introduced to countries in the Far East such as Malaysia, Indonesia, Myanmar, Cambodia, China and Vietnam.
During World War II, when the military demand was huge, the supply of natural rubber to these countries was cut off, which accelerated the development of synthetic rubber, especially in Germany and the United States.
Today, most natural rubber still comes from the Far East, while Russia and its former Soviet states, France, Germany and the United States are the world's leading producers of synthetic rubber.
The world's largest single source of latex rubber is the Harbel Rubber Plantation near Monrovia, Liberia, established by the Firestone Tire Company in the 1920s and 1930s.
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What can rubber do?
The physical and chemical properties of a material determine its use. Even if you don't know anything about the real purpose of rubber, you can make some good guesses.
For example, everyone knows that rubber is strong, stretchy, durable and waterproof, so it is conceivable that it can be used in waterproof clothing.
There are many products made of rubber, but the most important use of rubber is in car tires; about half of the world's rubber ends up wound up on the wheels of cars, bicycles, and trucks!
Since it is highly impermeable to gases, the tire can remain inflated for a long time.
Rubber can become not only soft, but also hard, and it is these qualities that greatly increase the range in which it can be used.
Soft and stretchy latex is used in everything from erasers, balloons, protective gloves, adhesives to paints.
Hard rubber can be used for shock-absorbing cushions and inflatable boats.
Because rubber is strong, flexible, and has poor thermal and electrical conductivity, it is also commonly used as a cable.
In addition to that, it has a very wide range of applications: from artificial hearts to waterproof gaskets for washing machine doors, you will find it in every application!
Neoprene is the better-known of all kinds of rubber, but it has applications far beyond what most people know about, not only is it often used in medical, but it is also widely used as a rubber due to its flexibility and water resistance. Building materials such as roof and floor sealants.
Rubber Diaphragm
While the world has a huge demand for new rubber, we also produce a lot of rubber waste, especially discarded car tires.
According to the Rubber Manufacturers Association, nearly 270 million scrap rubber car tires were produced in the United States in 2011 alone, accounting for about one-third of global tire use.
While some of it is used to make floors like children's playgrounds, more than half of it is wasted (whether burned as fuel or buried in landfills).
Here the editor reminds everyone that although rubber is good, pay attention to environmental protection
Body Rubber Seals
A Brief History of Rubber
1492: Long before Columbus discovered the Americas, Indians living in Central and South America had learned how to make waterproof clothing and shoes from the latex of the rubber tree. They called the rubber tree "cahuchu" (crying wood), which is why French rubber is still called natural rubber today (pronounced "cow-chew").
1731: During an expedition to South America, French explorer Charles Marie de La Condamine sends rubber samples back to Europe, sparking intense scientific interest.
1770: The discoverer of oxygen, British scientist Joseph Priestley, discovers that he can use a rubber sheet to erase pencil marks on paper. In England, erasers are still widely known today as "rubber".
1791: Englishman Samuel Peal develops a method of making waterproof cloth from a rubber solution.
1818: Scottish medical student James Syme uses rubber-coated cloth to make raincoats.
1839: American inventor Charles Goodyear accidentally discovered how to vulcanize rubber after throwing a piece of material (treated with sulfur) onto a hot furnace.
1876: British explorer Sir Henry Wickham smuggled thousands of seeds from Brazil's rubber tree, Hevea brasiliensis, and returned to England.
The British planted the seeds at Kew Gardens outside London and exported them to various countries in Asia, establishing the giant plantations that now supply most of the world's rubber.
1877: American rubber manufacturer Chapman Mitchell develops the first process for recycling rubber.
1882: John Boyd Dunlop invented the pneumatic (pneumatic) rubber tire, after which the demand for rubber began to explode.
1930: A team of DuPont American chemists led by Wallace Carothers developed a revolutionary synthetic rubber called polychloroprene and sold it as neoprene. (Soon after, the same group developed an even more revolutionary material: nylon)
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