We all use plastic items in daily life. But do you know how plastics are made? In this article, we will learn about the process of making plastic in industries –
How are plastics made?
If we talk theoretically, in easy terms, plastics are made with the help of crude oil and many types of natural materials like cellulose, coal, natural gas, salt, etc.
It is a very strong and long-lasting material. Through which we use items made on a large scale. Just as everything present in the world has both good and bad aspects, similarly the use of plastics has also led to bad results like environmental pollution.
Initially, the invention of plastic did not seem less than a boon. Because till today, almost a hundred years ago, humans used items like bones, wood, turtle shell, ivory, etc. instead of plastics. Due to which a lot of wild animals were hunted. Also, the number of goods available at that time was quite limited.
Actually, we will not talk much about the history of plastic in this article because we have already written an article about it. That you can read –
Process of Making Plastics –
Friends, let me tell you that large-scale plastic is manufactured industrially only through crude oil. So for this, we will tell you here the process of making plastic from crude oil.
The plastic manufacturing process has so many steps but these steps are most common and highlighting –
- Extraction of Crude Oil
- Refining of crude oil
- Cracking Process
- Polymerization Process
- Compounding and Processing
Let’s know these steps in detail –
Step 1 Extraction of Crude Oil –
The first step in the manufacturing of plastics is the Extraction of Crude Oil from the earth. By which Many petroleum products like petrol, diesel, kerosene oil, etc. are made.
Step 2 Refining of crude oil –
The crude oil emanating from the ground is a mixture of thousands of complex impurities. So therefore firstly the crude oil is sent to the oil refinery for the distillation process. Where many types of hydrocarbon mixture called fractions are found. These fractions have different sizes and molecular structures. In the Refining process of crude oil, we get a fraction called Naphtha, which is used in the manufacturing of Plastics. Naphtha contains ethane and propane gases.
The Refining Process contains these processes –
- Heating crude oil in a furnace
- Separation of heavy Crude oil into lighter components by Distillation Process
- One of these Components Called Naphtha is found.
- Naphtha contains ethane and propane gases.
Step 3 Cracking Process
After Refining Process, Cracking Process starts. Here Ethane and propane are treated with heat at different specific temperatures (about 800–900 °C). After Cracking Process we get light olefin gases (gasoline) such as ethylene, propylene, butylene which are actually monomers.
Step 4 Polymerization Process
The last process to obtain plastic from Crude Oil is Polymerization. Here monomers are combined together to create higher molecular hydrocarbons which have a long chain of monomers. The polymerization process needs specific catalysts to complete the reaction of making polymers i.e plastics.
there are two types of polymerization processes –
- Addition polymerization
- Condensation polymerization
Step 5 Compounding and Processing
In this Process, Plastic Polymers turned into granules or pellets. Also during the compounding process, the plastic raw material is prepared for further processing according to the application.
Now, these granules or pellets of plastics raw materials are used in making various products by injection molding, extrusion molding, etc.