What Are Plastic Bags?
Plastic bags have been a part of our lives. But have you ever stopped to ask yourself what the lightweight bag is made from? Why is it considered a danger to the environment? In this blog, we look at the different types of paper bags and what they are made out of.
To help you understand the construction of plastic bags, you need to start by understanding plastics in general. They are created from a group of synthetic molecules known as polymers.
Polymers are created by repeating a molecular pattern using monomers as units. In plastic bags, the repeating structures are made using ethylene, which is chemically changed to polyethene – the founding basis of all plastic bags.
Polyethene is made by winding many chains of carbon atoms then bonded to hydrogen atoms. Because of the patterned structure, plastic is easy to mould into different densities and shapes.
Where are the raw materials of plastic bags sourced from?
There are various sources of polyethene, but the single most common form is a fossil fuel. The raw materials can be extracted from petroleum or natural gas. When finely refined, both petroleum and natural gas yield ethylene, which is then turned into polyethene.
The first type of plastic bag is made from High-Density Polyethylene plastic. It is the most common type of plastic bag often used to make shopping bags.
This type of plastic is made of straight molecule chains that don’t branch much. They stay linear from the beginning to the end. Because of this linear structure, the resulting product is a strong plastic, creating light shopping bags that can hold many times its weight without tearing.
Low-Density Polyethylene is the opposite of HDPE plastic. Unlike HDPE plastic, LDPE plastic forms branching chains of polymer materials. In this case, the polyethene chains don’t stay linear. Instead, they branch out, forming many different combining lines.
The resulting material is a very light type of plastic that feels almost like a film. This type of plastic is used to make tear-away plastic bags like the ones used by dry cleaners.
These types of plastic bags have the same strength as HDPE versions. However, this type of plastic material doesn’t branch and is thicker and heavier than HDPE versions. LLDPE plastic is used to make the plastic bags used in clothing stores.
The Bottom Line
Although plastic bags are made from different types of plastic, one thing is for sure, the base material is a polymer that is often extracted from natural gas or petroleum.
Plastic bags can be recycled. However, they can’t be made into an organic state. They can only remain in their synthetic substance. They are also notoriously hard to decompose, taking many years to decompose fully.
If you have to use plastic, the least you can do is re-use it. Because of its sheer strength, you can use it multiple times for various applications without noticeable degradation.