What Is Polyester? And Is It Sustainable?

Polyester fabric, commonly associated with affordable, wrinkle-resistant fast fashion, is a synthetic fiber known for its versatility and ease of wear. Moreover, its affordability compared to natural fibers has made it a top choice in the textile industry. In fact, as of 2017, polyester accounts for 80% of synthetic fabrics and nearly half of the global fiber market².

This article provides an objective analysis of polyester and its consequential environmental impact.

Related Read: Rayon Fabric, Bamboo Fabric.

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Brief history of polyester fibers

So when did the polyester fabric come on the scene? Well, it goes way back to the 1930s. W.H. Carothers and his team invented the polyester fabric around this time, but it was not until 1941 that it was expanded and further developed by two British scientists - W.K. Birtwhistle and C.G. Ritchie. 

DuPont purchased the rights from these two British scientists and developed their own polyester fiber called Dacron. Unlike natural fibers like cotton and wool, it was born from scientific research. It greatly appealed to many, especially women, because of its affordability, durability, and low maintenance. 

Today, polyester fibers have become synonymous with the fast fashion industry and are the most widely used synthetic fibers. 

What is polyester?

Polyester, or polyethylene terephthalate (PET), is a synthetic fabric manufactured from petroleum and other chemical compounds. 

The polyester fiber is formed from a chemical reaction between alcohol and acid. Manufacturers do this by mixing ethylene glycol (derived from petroleum) and purified terephthalic acid. It is made up of and characterized by the following chemicals: 

• PET (Polyethylene Terephthalate)  is the most widely used grade of polyester. 
• PBT (Polybutylene Terephthalate) has greater chain flexibility and lower melting temperature than PET
• PEN (Polyethylene naphthalate) has low oxygen permeability. Manufacturers often use it for packaging applications where the product is sensitive to oxidation. 
• PTT (Polytrimethylene Terephthalate) is commonly used in the textile industry because of its durability and staining resistance. 

Other types of polyester

While PET is the most common, there are other types of polyester used for making polyester products: 

PCDT polyester 

PCDT polyester ( poly-1, 4-cyclohexylene-dimethylene terephthalate) is a less popular than PET. The process of making PCDT is similar to that of PET, but it has a different chemical structure. 

PCDT is more durable and elastic, making it ideal for manufacturing heavy-duty applications like upholstery and curtains. 

Plant-based polyester 

Manufacturers make it plant-based by using ethylene glycol and dimethyl terephthalate. However, while other kinds get ethylene from petroleum, this type comes from renewable sources like sugar cane. 

It is also biodegradable compared to other types of polyester. However, it is less durable. 

How do manufacturers produce polyester?

The manufacturing process to create polyester fabric all starts with extracting crude oil from the ground. Petroleum is a source of the required raw materials manufacturers use for creating polyester-ethylene glycol and terephthalic acid.

Next, these raw materials go through a chemical process called polymerization to form what we technically call polyethylene terephthalate (PET). Manufacturers mix both materials with dimethyl terephthalate under high heat to create PET. 

Then, manufacturers extrude the resultant PET plastic pellets through holes on a spinneret device to form long filaments. Manufacturers may alter these holes to create fibers of different qualities.  After this, they leave the filaments to cool and solidify. 

Next, manufacturers stretch this man-made fiber to improve its strength. They then texturize and cut them into usable forms similar to natural fabrics. They then spin them into a yarn, which they can use alone or with other fibers to weave into a fabric. 

The final stage of the production process involves dyeing, printing, and finishing to make polyester products.  

Characteristics of the polyester fabric

Here are a few characteristics that make the polyester fabric unique: 

• Durability: Polyester is one of the most durable materials. It can last for more than a decade without damage. It is also very lightweight. It is also able to retain its shape, making it ideal for making gym wear. 
• Moisture-resistant, breathable, and wrinkle-free: Perhaps one of the major selling points of the polyester fabric is that it is wrinkle-free. You can wear clothing without having to iron them. It is also very lightweight, making polyester breathable.

However, it can't absorb moisture and will wick away it instead of soaking it like cotton fibers. This can be uncomfortable, especially if you have sensitive skin. 

• Soft texture: Polyester is soft and smooth, making it ideal for clothing and home furnishings. It is just as soft as silk, making your clothing and bedding comfortable for home use. 
• Easy to maintain: Another quality that polyester has is that it is easy to maintain. You can wear clothing without having to iron it. It is also very easy to clean and can last long without wear and tear. 
• Affordable: Polyester is one of the most widely used fabrics in the textile industry because of its affordability. Its production involves the use of synthetic materials, which reduces costs. 

Uses of the polyester fabric

Synthetic fiber polyester has a wide range of uses, including: 

• Clothing: It is one of the most widely used synthetic materials in the world. Manufacturers weave polyester yarns into fabrics that they use to make polyester clothing, like everyday shirts, jackets, pants, outdoor clothing, and other garments. 
• Home furnishings: Manufacturers use polyester fabric to make home furnishings like curtains, blankets, pillowcases, sleeping bags, and bed sheets. Thanks to its insulation properties, manufacturers also use the fabric to make cushioning materials for pillows. 
• Industrial applications: You can also find the polyester fabric used for industrial applications like LCDs, cords, safety belts, food containers, and other industrial products. 
• Plastic bottles: Polyester is also a common raw material for plastic PET bottles. Being a very durable material, they don’t degrade quickly, making it ideal for plastic bottles. 
• Sports gear and equipment: Polyester is a durable and breathable fabric. It is ideal for making sports polyester garments and equipment like gloves and other sportswear.

Is polyester sustainable?

Polyester is a versatile fabric for clothing, furniture, and other products. However, while it has become a staple in the fashion industry, it is not sustainable and has a negative environmental impact. 

Here are the ways through which it impacts our environment: 

Greenhouse gas emissions and energy consumption 

Polyester is a synthetic fabric manufactured through a process called polymerization. Manufacturers combine both ethylene glycol and terephthalic acid under high heat to create PET. The heating of these monomers requires very high temperatures that involve the burning of fossil fuels like oil, natural gas, and coal, consuming energy. 

In addition, burning these fossil fuels releases carbon dioxide and other greenhouse gases, contributing to climate change.

Related Read: What Are Greenhouse Gases?

Dyes and toxic chemicals   

Manufacturers dye the polyester fabric using certain chemicals that help the dyes sit in the fabric. Chemicals like formaldehyde and heavy metals contain harmful substances that can negatively impact human health and the environment. 

So, workers in these dyeing facilities are exposed to these toxic chemicals, which can lead to serious health conditions in the long run. These toxins can also enter water systems like rivers¹, lakes, and oceans, polluting our waterways and affecting marine life. 

Water usage 

Polyester production requires a significant amount of water, especially for cooling. After PET undergoes heating, it will need to be cooled down. Manufacturers use water to cool down the machinery and the plastic pellets. 

In large-scale production facilities, this can involve a lot more water. Also, without proper water treatment, discharged water can become contaminated, polluting our water bodies and affecting marine and human life. This can further increase water scarcity issues in locations with limited water resources. 

Microplastics 

Microplastic pollution is one of the most common impacts of polyester on our environment. As we know, it is made with plastics that do not biodegrade, so they shed microplastics during washing. 

As you wash your polyester clothing, tiny plastic particles filter through filtration systems and into our water bodies. 

These microplastics accumulate in our water system, becoming accessible to aquatic life. These aquatic organisms can ingest these microplastics directly or indirectly when they feed on organisms that have ingested microplastics. 

This can go further up the food chain and affect humans who consume these marine organisms. In fact, according to research, the average human consumes around 1769 plastic particles weekly³. 

In the long term, this can harm humans, aquatic life, and the environment. 

Related Read: Environmental Impact of Microplastics.

Non-biodegradability 

Biodegradation involves the breakdown of organic substances through natural processes. It happens with the aid of microorganisms, water, carbon dioxide, compost, and so on. 

Cotton, wool, and other natural fibers can undergo this process. However, polyester is a kind of plastic, and just like other plastics, it does not break down easily. In other words, they could remain in the environment for as long as hundreds of years, contributing to pollution. These plastics could also affect soil health and pollute our waterways. 

Problems with recycling 

Recycling polyester is one way to reduce its environmental footprint. However, while technology has come to save the day, reducing its impact comes with its limitations. We still lack a robust global infrastructure for recycling used polyester clothing and products, reducing recycling rates. 

In addition, most clothing comes from virgin polyester, and the few that come from recycled polyester don’t come without issues. While the recycled kind reduces carbon emissions compared to the virgin type, it degrades over time. This means that you cannot recycle it indefinitely. 

Also, manufacturers blend polyester with other fabrics like cotton. This makes it even more difficult to recycle. So, most of them end up in landfills or incinerated. As we already mentioned, this material takes hundreds of years to break down. 

Overall, recycled polyester is more sustainable than virgin polyester because recycled plastic requires lower energy and releases less greenhouse gas emissions. 

Related Read: Why Do People Not Recycle?

Sustainable polyester alternatives

You can go for recycled fibers and other sustainable polyester alternatives. Here are more sustainable alternatives to this material: 

1. Recycled polyester 

Recycled polyester is more sustainable than virgin polyester. This is because it does not require burning fossil fuels, contributing to climate change. It also comes from using recycled plastic bottles, which reduce waste. 

Manufacturers then use these recycled polyester fibers to make clothing, bedding, and other products. Brands like Bionic and Parley for the Ocean are examples of brands that use recycled polyester. 

2.  Bio-polyester 

Bio-polyester or plant-based polyester is another sustainable alternative. Manufacturers produce it using renewable resources like crops and bio-waste instead of PET or other petroleum sources. 

However, while bio-polyester may be a more sustainable option, it can come with sustainability issues. For example, if the crop is a Genetically Modified (GM) crop or if the raw material wasn’t farmed sustainably. 

3. Organic cotton 

You can ditch polyester altogether for natural fibers like organic cotton. It is more sustainable than conventional cotton, as farmers rely on rainwater instead of extracting water from the ground. 

It is also free of pesticides and other hazardous chemicals, making it great for you and the planet. Also, it emits far less greenhouse gas and uses less energy for its production. 

4. Hemp 

Hemp is a natural fiber that has been around forever. It is also one of the most sustainable fabrics on the market. It requires very little water to grow and returns nutrients to the soil. 

In addition, it is breathable and biodegradable, making it food for you and the environment. So, instead of polyester, you can switch to clothing and other products made with hemp. 

5. Tencel

Tencel is quite similar to the rayon fabric but is more sustainable. Manufacturers make them from wood pulp without large amounts of water or any hazardous chemicals. It is also easy to recycle since you can recycle most of the raw materials used to make the fabric. 

6. Organic linen 

Linen is a very lightweight fabric that is breathable and comfortable. Organic linen comes from the flax plant, making it a more sustainable option. Its production requires little water and energy, making it a more sustainable fabric than polyester. 

Wrapping up on polyester fabrics 

Polyester is one of the most widely used fabrics by clothing manufacturers. It is versatile, easy to manipulate, breathable, and easy to maintain. From clothing to bedding and equipment, among other products, it is a common fabric. 

However, the material and its production are not sustainable. Over the years, this has led to the introduction of more sustainable fabric options like bio-polyester, recycled polyester, and organic fibers.