Plastic can be found anywhere, from water bottles and toys to clothing. But have you ever wondered how plastic is made?
This article will explore the process of making plastic and discuss some of the benefits and drawbacks of this versatile material. So, without further ado, let’s take a closer look at the fascinating world of plastic.
Learn in This Article
- What Is Plastic
- Types of Plastic
- How Is Plastic Made
- Plastic vs. Polymer
- What Are Hydrocarbons
- How Is Synthetic Plastic Made From Crude Oil
- How Is Plastic Made From Naphtha
What Is Plastic
Plastic is a versatile and affordable material used in various products, from food packaging to building materials. Generally, it’s made from synthetic or semi-synthetic materials that bring a set of benefits, including a high strength-to-weight ratio, durability, and the ability to be molded into different shapes.
Unfortunately, plastic also causes a number of environmental issues. Because plastic is mostly made from non-renewable fossil fuels, it can take centuries to decompose. And not only that. It releases harmful toxins that can affect humans and wildlife.
Types of Plastic
Before jumping right into the process of making plastic, it’s important to understand how plastic is categorized. Here’s a list of the most common kinds of plastic:
- High-Density Polyethylene (HDPE)
- Polyethylene Terephthalate (PET or PETE)
- Low-Density Polyethylene (LDPE)
- Polyvinyl Chloride (PVC or Vinyl)
- Polystyrene (PS or Styrofoam)
- Polypropylene (PP)
How Is Plastic Made
Extraction of Raw Materials
The first step in the plastic manufacturing process is the extraction of raw materials. As already mentioned, plastic is made from synthetic or semi-synthetic materials, all of which are derived from fossil fuels. The most common ones include natural gas, crude oil, and coal.
These fossil fuels are extracted from the ground and then refined to create hydrocarbon-based feedstocks used to make plastic.
In this stage, crude oil is transformed into petroleum plastics. The extracted materials are heated in a furnace where the refining occurs. The heavy crude oil is sent to the distillation unit, where the material is divided into lighter components, known as fractions. For example, naphtha is a crucial gas in making a large amount of plastic.
Polymerization is the process of converting monomers (ethylene, propylene, butylene) into polymers or hydrocarbons. There are two main types of polymerization: addition polymerization and condensation polymerization.
Also known as chain-growth polymerization, additional polymerization involves the addition of monomers to a growing polymer chain. The most common type of addition polymerization is ethylene polymerization, which is used to make polyethylene.
Compared to addition polymerization, condensation polymerization involves linking two monomers together to form a dimer, which then reacts with another monomer to form a trimer, and so on.
After the polymer has been created, it undergoes a final process named compounding. This is where additives such as fillers, plasticizers, and colorants are added to the plastic to give it the desired properties.
While fillers increase the strength and stiffness of the plastic, plasticizers can make this material more flexible.
Plastic vs. Polymer
The term polymer comes from the Greek word “poly” (many) and “mer” (repeating unit). On the other hand, the word plastic comes from “plastikos,” the Greek word for “capable of molding.” This meaning relates to the flexibility of plastic but also plastic surgery.
While not all plastics are polymers, all polymers can be used to make plastic. In fact, plastics are high molecular weight polymers. The most common ingredients in plastic are carbon, hydrogen, oxygen, nitrogen, sulfur, and chlorine.
What Are Hydrocarbons
Hydrocarbons are a type of molecule consisting of both nitrogen and chlorine. They are found naturally in the environment and are necessary for the manufacture of many products, including plastics, pharmaceuticals, and fertilizers.
There are two main types of hydrocarbons: saturated and unsaturated. Simply put, saturated hydrocarbons have all their carbon atoms bonded to each other, while unsaturated hydrocarbons have at least one double bond between two carbon atoms.
How Is Synthetic Plastic Made From Crude Oil
Synthetic plastic comes from petrochemicals. In this sense, oil gets directly drilled through rocks and extracted from the soil.
After the extraction process, oil gets pumped into a pipeline that leads to an oil refiner. However, it’s extremely important not to spill oil during transportation. If that occurs, it might pose severe dangers to the environment.
How Is Plastic Made From Naphtha
Naphtha is a colorless, flammable liquid hydrocarbon mixture derived from petroleum. It’s used as raw material (feedstock) to produce synthetic rubber and fibers such as nylon and polyester. Naphtha-based feedstocks are also used as solvents and diluents.
Generally, naphtha is kept in hot water, decomposed at about 800°C or 1,472°F, and separated into two hydrocarbons.
Frequently Asked Questions
Who invented plastic?
Plastic is a material that has revolutionized many industries. It’s strong, durable, and easy to mold into any shape, making it ideal for everything from packaging to construction. But who invented plastic?
In 1892, a metallurgist and inventor, Alexander Parkes, was responsible for patenting Parkesine. At the time, plastic was a less expensive material than ivory and tortoiseshell.
How long will plastic last?
For example, plastic bottles may take up to 450 years to decompose, while plastic straws take 200 years. But even then, plastic is never entirely gone. As it decomposes, it releases toxic chemicals and breaks down into microplastics. Some tests show that microplastics can cause severe damage to human cells.
Can you make plastic without oil?
It’s possible to make plastic without oil, though it’s not currently done on a large scale. In many cases, plastics can be made from cellulose and other renewable materials. This approach is commonly known as “bioplastic.”
What was used before plastic?
Before the invention of plastic, materials like glass, metal, clay, paper, and cloth were used to make furnishings, toys, etc.
In some cases, natural materials like natural gums and rubber were used to create more flexible and malleable objects. While these materials are still in use today, they have largely been replaced by plastic. Thanks to its durability and versatility, plastic has become one of the most popular materials in the world.
How Is Plastic Made: Key Takeaways
- Plastic is made from high molecular weight polymers, which are chains of small molecules called monomers.
- The most common ingredients in plastic include carbon, hydrogen, oxygen, nitrogen, sulfur, and chlorine.
- Hydrocarbons are a type of molecule consisting of both nitrogen and chlorine. They are found naturally in the environment and used to make plastics.
- Naphtha is a colorless, flammable liquid hydrocarbon mixture used as a raw material to produce synthetic rubber and fibers.
- Plastic is strong, durable, and easy to mold into any shape, making it ideal for everything from packaging to construction.