variety colour of plastic material

What are Plastic Bags Made of?

Plastic bags are widely used in our everyday lives for a variety of purposes. Every day, we see plastic bags everywhere, fulfilling different necessities and making our lives easier.

Despite the widespread usage of plastic bags, many people are not familiar with the composition of plastic bags.

Generally, plastic bag manufacturers perform a series of manufacturing processes before the plastic bags are ready to be sent to the plastic bag suppliers and reach the consumer.

Keep reading to learn what plastic bags are made of and how they are made.


What Are Plastic Bags Made of?

The majority of plastic bags are made from a polymer substance called polyethylene. It is made of long chains of ethylene monomers. High temperature and pressure are applied on a large number of small plastic pellets to liquefy the material and later cut it into proper shapes and bags.

The original form of polyethylene is ethylene, which is a type of gas found in coal gas, crude oil, and natural gas. After extracting ethylene, it is combined with a catalyst like a benzoyl peroxide to obtain the polyethylene material and make plastic bags and other types of packaging.

Different methods to produce ethylene from renewable resources are also becoming quite popular nowadays.


How Are Plastic Bags Made?

The very first step of making a plastic bag includes extracting the raw material, polyethylene, from refined oil or cracked gas. Wells are drilled to obtain the hydrocarbons through fracking by injecting a mixture of water and chemicals into the rock formations to release oil and gas. Special attention is given to ensure there are no leakages. Otherwise, it can result in severe consequences for the environment and human health.

Extracted oil and gas are transported to a refinery through pipes, and petroleum is separated into varying densities to ensure the right kind of oil is being used to manufacture plastic. The second major step is performed by the plastic bag manufacturers when they provide extreme heat and pressure to the raw plastic pellets to produce molten liquid.

Plastic film extrusion involves turning the molten plastic into a balloon-like plastic film and passing it through a tall vertical corridor. Various kinds of rollers are used to stretch and contort the plastic into thin-film sheets.

Generally, plastic bags are made of pure polyethylene molecules. Additionally, the trend of using plastic bags with company logos and names is becoming prevalent for marketing and branding purposes.

The process of printing on plastic bags is known as flexographic printing. It is important for plastic bag manufacturers to use suitable dyes because colour printing can be a toxic process.

The final step of producing a plastic bag involves pressing two printed sheets together at the edges to completely seal the bag. The sealed bag can easily be cut into desired shapes and sizes, depending on the commercial purpose of the bag.

Moreover, plastic bag manufacturers also have the option of creating custom designs on the bag and adding sections to the bag.


Benefits of Using Plastic Bags

Following are some of the major benefits of using plastic bags:

1. Flexibility

Plastic bags are made of flexible material, and this allows them to offer more space. As a result, the walls of the plastic bags are not rigid, so you can easily fit a lot of items in them.

2. Strength and Reliability

Another useful property of plastic bags is that they are strong and reliable. A traditional plastic bag is capable of holding up to 50 pounds. You can fit different kinds of groceries in them, and this makes plastic bags extremely popular in grocery stores all over the world.  

3. Water-Resistant

Plastic bags are naturally water-resistant. It means that you can easily carry your groceries and many other things with plastic bags without worrying about them getting damaged by water.

4. Affordability

A significant advantage of plastic bags is that they cost much less than paper bags. As a result, all types of businesses, especially small-scale companies, can use plastic bags for a limited budget.


All In All

The production of plastic bags is a complicated process. However, this process is getting more streamlined and efficient with the use of modern tools and technology that speed up the extraction and refinement of ethylene and the production of plastic bags.

With various benefits offered by plastic bags, it’s no doubt that plastic bags will continue to be popular for both commercial and domestic usages.