1 شهریور 1402

زمان مورد نیاز برای مطالعه : 11 دقیقه

' 11

What is plastic

Plastic is a product that is used for various purposes. Plastic may be hard or soft, transparent or opaque. It can look like wood or leather or silk. It can be used in making toys or heart valves. There are more than 10,000 different types of plastic. The primary raw materials for making plastic are oil and gas. These fossil fuels are sometimes combined with oxygen and chlorine to make different types of plastic.

Many of the things you buy come in plastic covers and packages. You probably open every package and throw away the box or plastic container without paying attention. But if all these boxes and containers Collect plastic, what happens? How much plastic waste do you collect in a month, such as soda bottles, plastic bags, and empty pens?

Some types of plastics are recyclable and some are not. Many people think that plastics are waste that is ultimately irreversible or because they consume fossil fuels.

They are called energy-consuming. If this is not the case, plastics are very efficient in terms of energy and consumption. That is, much less energy is used to make a plastic bottle than to make a glass bottle. Also, since plastics They are light in weight and less energy is used to transport them. Although plastics are generally light, their disposal in landfills is not a good option, there are two other ways, recycling and incineration. The use of these methods leads to the recovery of some Values ​​of plastic that can be used in re-making plastic items.

The waste incinerator recovers chemical energy that can be used to generate steam and electricity. In the event that ground burial of plastics does not have any of these advantages, and in addition, sanitary burial of plastic means permanent burial because this type of waste does not decompose. to be

The plastics industry is very important due to its strong connection with the oil industry.

In fact, it can be said that if there is no oil, we will not be able to produce plastics. Until the mid-1950s, the main source of raw material for the plastic industry in Europe was coal, in this regard, coal tar, coke, coal gas, and ammonia, coal tar is a source for aromatic chemicals such as benzene, toluene, phenol, naphthalene, and related compounds. which eventually led to the production of important plastics such as polystyrene resins and nylons.

The development of the petrochemical industry is probably the biggest unique factor in the growth of plastics, for this reason, the petrochemical industry is noticeably visible in our daily life through the production of plastics.

Historically, the plastic industry has experienced very rapid growth. Although artificial plastics have widely penetrated the market since the end of the 19th century. But in fact, this industry grew with the end of the Second World War and the entry of relatively cheap petrochemical raw materials into the market, and our current era can be called the era of plastics;

The direction of construction and the speed of growth of this industry is more than other industries. This is due to the advantages of new technologies and the intervention of economic parameters in replacing plastics instead of materials such as metal, glass, wood, ceramics, etc. For example, we can mention the replacement of a plastic pipe due to its price and ease of installation and connection in comparison with its metal sample. At present, due to the new developments in the automotive industry or household appliances, plastic parts have become a very suitable substitute for metal parts in this category of products due to weight reduction and increased fuel efficiency. He pointed out that today, among the types of polymeric plastics in the market, about 70% of them belong to the four groups of PVC, PE, PP, and PS.

The direction of construction and the speed of growth of this industry is more than other industries. This is due to the advantages of new technologies and the intervention of economic parameters in replacing plastics instead of materials such as metal, glass, wood, ceramics, etc. For example, we can mention the replacement of a plastic pipe due to its price and ease of installation and connection in comparison with its metal sample. At present, due to the new developments in the automotive industry or household appliances, plastic parts have become a very suitable substitute for metal parts in this category of products due to weight reduction and increased fuel efficiency. He pointed out that today, among the types of polymeric plastics in the market, about 70% of them belong to the four groups of PVC, PE, PP, and PS.

1- Natural

2-Semi-artificial

3- Synthetic or industrial plastics

In the case of natural plastics, we can refer to materials such as resins-biomin and resins. In the case of semi-synthetic plastics, we refer to a material such as gasine, whose main root is milk, which is used in the manufacture of brush handles, buttons, and wood glue. "It is useful.

But the industrial plastics that have been widely used include many parts such as gears and phone parts, whose main source is coal, among these materials are formaldehyde, urea, formaldehyde, and carbon fluorine.

The history of plastics

For the first time in 1862, Hiett brothers succeeded in producing celluloid, and about 40 years later, a person named Buckland succeeded in producing bakelite, and between 1921 and 1928, some nylons, as well as urea-formaldehyde, etc., were marketed in In 1934, polyvinyl chloride was launched in the market in commercial quantities to make various products.

But the most important period of development of plastics happened in the 1950s to 1960s, when the era of invention and production of different types of plastics with diverse properties and applications was called a turning point in this industry.

During these times, scientists such as Ziegler from Germany or Nata from Italy clarified the principles and methods of polymerization and caused the emergence of new technology for the production of various polymers such as polyethylenes, polypropylenes, polyethers, epoxies, etc.