What Are Plastic Bags Made Of?

The plastic bag debate has been long and unending. On the one hand, they are the convenient package that is easy to carry around, reusable and easy to clean. On the other hand, they wreak havoc to the environment because they are not degradable. We source Jute bags and belive is saving the world.

What is interesting is that the process of making plastic bags begins with natural gases. While you would expect a more favourable ending to a process that begins naturally, that is not the case. That is because there are other processes and products added during the process that give plastic bags their horrible reputation with regards to disposal.

How are Plastic Bags made?

Plastic bags are made from an ever available polymer known as polyethylene. The polymer starts out at ethylene commonly extracted from natural gases. To make a polymer, the gases are treated to form long chains of hydrogen and carbon atoms.

Why not also read: How to Recycle Plastic?

Depending on the type of polyethylene, the chains can vary but, they are all used to make different types of plastic bags.

How are Ethylene and polyethylene made?

The process of creating plastic involves the creation of groups of molecules known as polymers. Polymers are easy to develop and require repetition of the same molecular pattern which is created in units known as monomers.

When making the plastic bags, the structures of the monomers are made of ethylene which is changed to polyethylene through a chemical process. Polyethylene is the building block of all plastic bags.

Because of the patterned stricter, the structure of polyethylene can be easily manipulated into different shapes and densities depending on the application and use of the plastic.

Where Do Ethylene and Polyethylene Come From?

Even though the source of polyethylene can vary, it’s most commonly from some form of fossil fuel. Natural gas and petroleum (both derivatives of fossil fuel) are sources and vital ingredients in the making of plastic bags.

Why not also read: Alternatives to Plastic Bags

When petroleum and natural gas are refined, they yield ethylene. The ethylene forms the basis from which chemical processes yield polyethylene. Once formed, Polyethylene can be formed into any shape or colour depending on preference.

This is the most common type of polyethylene. It’s used to make plastic shopping bags. Bags made from High-Density Polyethylene (HDPE) have straight molecule chains that have very little or no branches. The molecule chains stay linear from the beginning to the end.

Because of the nature of the molecule chains, the end product is very strong and can hold a significant weight before breaking. That’s why they are preferred as grocery bags because they are lightweight and they can hold many items before tearing.

LDPE plastic is the opposite of HDPE. The molecule chains in this kind of plastic bags are low density with numerous branches in many different combining lines. The unique nature of the chain makes the end-product lightweight and almost film-like. These types of bags are used by dry cleaners to wrap cleaned clothes.

Linear Low-Density Polyethylene plastic does not branch. They are not as strong as HDPE. They are thicker in comparison and heavier compared to traditional grocery bags. They are commonly used in clothing stores. Sometimes they have a shiny appeal.

Effects on the Environment

Even though plastic bags can be recycled, they cannot be broken down into an organic state. Once the bags have been created, they are synthetic all their lives. However, they are usually recycled to make other synthetic materials like composite lumber.

General plastic bags are preferred because they use 70% less energy to produce and they also release 50% fewer greenhouse gas particles compared to other paper gases.