Recycled polyester, also known as rPET, is made from recycled plastic bottles. Therefore, it is an excellent way to minimise plastic in the landfills. At the same time, its production requires fewer resources as compared to new fibers. As a result, it generates fewer CO2 emissions.
In 2008, around 8% of polyester fibers produced globally came from recycled materials. By 2020, this figure reached 15%. Usually, recycled polyester is produced with PET plastic bottles. Other plastic waste like used polyester textiles and ocean waste can be used.
How to Recycle Polyester?
There are two ways to recycle polyester: mechanical and chemical. Mechanical recycling is when plastic is melted and turned into yarn. The problem of this method is that it can only be done for a few times as the fiber eventually loses its quality. Chemical recycling, on the other hand, allows the material to be recycled indefinitely because it involves breaking down the plastic molecules and transforming them into yarn. This process, however, is more expensive.
Recycled Polyester: Advantages
#1 Decrease waste in the landfills and in the ocean:
Recycled polyester gives a second chance to non-biodegradable materials. It was estimated that more than 8 million metric tons of waste enter the ocean every year. This means that if this trend continues, in 30 years, there will be more plastic in the ocean than fish.
The situation in the landfill is not brighter. According to the World Bank, the world generates 2.01 billion tons of municipal solid waste annually. By 2050, global waste is expected to grow to 3.40 billion tons.
Recycling plastic is, therefore, an excellent way to minimise plastic waste and actually turn it into something useful.
#2 High quality, less resources
Recycled polyester is almost the same as virgin polyester when it comes to quality. However, according to a study of the Swiss Federal Office for the Environment, its production requires 59% less energy compared to regular polyester. Additionally, it was estimated that the production of rPET decreases carbon dioxide emissions by 32% in comparison to virgin polyester. Not to mention that recycling plastic waste can also minimise the extraction of natural gas and crude oil, necessary for the production of more plastic.
Recycled Polyester: Disadvantages
#1 Chemicals can be part of the recycling process and not only
Since recycling cannot always achieve the perfect white color, some dyers use chlorine-based bleaches to whiten the base. The inconsistencies that sometimes happen can lead to redyeing numerous times. This requires high usage of water, energy and chemicals.
Additionally, some studies found that PET bottles leach antimony. This is a carcinogen, which is toxic to the heart, lungs, liver and skin. Quantities found in PET bottles are too small to be considered toxic. However, recycling PET is a high-temperature process and it creates wastewater tainted with antimony trioxide. Moreover, when the both recycled and regular PET is burned at the landfill, antimony is released again as a gas. Antimony trioxide has been classified as a carcinogen in the state of California since 1990, by various agencies in the U.S. (such as OSHA, ACGIH and IARC) and in the European Union. That is probably the reason why the Textile Exchange lists Textile Exchange names “finding substitutions for antimony” as one of the main challenges rPET faces.
#2 Recycled polyester releases microplastics
Some experts also argue that rPET does not prevent plastic from entering the ocean. According to them, it can release microscopic plastic fibers known as microplastics. For example, according to a study from UK’s Plymouth University, each cycle of a washing machine releases more than 700,000 plastic fibers into the environment.
#3 More resources than other sustainable materials
It is true that rPET requires 59% less energy to produce than regular polyester. On the other hand, according to a report by the Stockholm Environment Institute, it requires more energy than hemp, wool and both organic and regular cotton.
#4 What to recycle?
Collection of PET bottles is limited around the globe. At the same time, the demand for polyester derived from these is growing. There are, of course, alternative sources. However, sourcing polyester from textile waste faces numerous challenges. For instance, recycling fabric blends as well as non-recyclable parts like zippers and buttons makes the whole process quite difficult.
Recycled polyester is definitely a sustainable alternative to virgin polyester. However, we need to be aware that as everything else on Earth – it is not perfect. Many of these benefits actually remain theoretical.
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