PET plastic, found in your daily beverage bottles, is one of the most recycled plastics today. Despite its controversial reputation, not only is PET a versatile and durable plastic, but recycled PET (rPET) has evidently resulted in a much lower environmental impact than its virgin counterpart. That is owing to the fact that rPET reduces oil usage and greenhouse gas emissions associated with virgin plastic production. So, what is rPET? How is it recycled? And what renders it sustainable?
rPET, short for recycled polyethylene terephthalate, refers to any PET material that comes from a recycled source rather than the original, unprocessed petrochemical feedstock.
Originally, PET (polyethylene terephthalate) is a thermoplastic polymer that is lightweight, durable, transparent, safe, shatterproof, and highly recyclable. Its safety is primarily evident in terms of being eligible for food contact, resistant to microorganisms, biologically inert if ingested, corrosion-free, and resistant to shattering that may be particularly harmful.
It is commonly used as packaging material for foods and beverages – mostly found in transparent bottles. Yet, it has also found its way into the textile industry, usually referred to by its family name, polyester.
As of 2019, polyester fibers have comprised the primary end-use segment of the rPET industry at about 45%. Still, other segments, such as bottle-to-bottle production, remain effective market drivers, as well. According to a report by Acumen Research and Consulting, the rPET market size is predicted to grow at a compound annual growth rate (CAGR) of no less than 8% to reach about US$ 12.5 billion by 2026. This projection is set as awareness of environmental sustainability has been increasing among customers, and multiple countries across Europe and North America have started establishing bans on landfills. This growth demonstrates an improvement in rPET’s adoption and a boost to its reputation.
Today, not only is PET the most widely recycled plastic in the world, but its production, collection, recycling, and reprocessing back into valuable material have also become increasingly efficient. This has enabled it to use fewer resources and less energy than ever before, rendering it more sustainable.
Sometimes, our greatest strengths can beget our greatest weaknesses. For PET, its high durability means it takes five to seven centuries for it to begin to break down if it ends up in landfills. This low degradation rate, alongside the increasing volume of PET production, has rendered it a contributor to the plastic waste crisis the world is facing today.
According to a 2017 IHS Markit report, the world has 30% more virgin PET capacity than needed. The North American market, in particular, has had surplus capacity for over 20 years, which has led to increased competition for market share between producers, lowering the price of virgin PET and increasing demand. As a response, instead of justifying the excess capacity, the industry increased production and overbuilt in multiple regions of the world, most notably Asia. This overcapacity has raised major concerns about the material’s end-of-life stages. How the material is discarded and whether or not it is collected, sorted, and recycled are of utmost importance to ensure we can properly make the most of rPET’s sustainability properties. Therefore, in order to minimize the amount of plastic waste ending up in landfills, it is crucial that we focus our efforts on recycling PET and encouraging its use over virgin PET.
Furthermore, the end-of-life stage is not the only period of a material’s life cycle where recycling plays a significant role. By allowing post-industrial PET waste to circle back and re-enter the production phase, the amount of raw material required for PET production decreases. Increased use of post-consumer and post-industrial recycled plastic means less extraction of natural resources and less energy needed for that extraction. Such a measure helps preserve these finite resources and lowers both the carbon footprint and embodied energy of the material. By doing so, we give rise to what experts call a circular economy for plastics, in which waste is minimized, carbon emissions reduced, and the material’s economic value maintained.
There are many elements that go into the process of recycling PET, and we must understand how recycling is actually done to make sure that everyone does their part in our efforts towards sustainability.
The process of recycling PET is made of 5 consecutive stages:
It all starts at the level of disposal of PET-based products, like PET bottles. Here, environmental awareness plays a critical role as consumers should be educated about the importance of proper recycling of plastic products. PET bottles and containers are identified by code #1, usually found on the bottom side of the container. This is an indicator that this product is PET-based. Disposing PET bottles separately can help streamline the recycling process, especially at the municipal level, as most municipal recycling programs collect PET in bottle form.
After the consumer discards a PET product in a recycling bin, it turns into PET waste. This post-consumer waste is then collected and transferred to a materials recovery facility (MRF). There, PET waste is separated from other waste stuff, gathered into bales of PET materials, and then passed on to specialised PET recycling facilities.
At the level of waste collection, particularly curbside collection, two different approaches are generally considered, single-stream recycling and dual-stream recycling. The difference lies in the type of recyclable materials put in the same bin. Whereas single-stream recycling means all recyclables are placed in the same container, dual-stream recycling requires that paper-based products be collected in a separate bin from plastic.
Independent of the collection approach, PET bales – and other material bales for that matter – should be handled, stored, and transported carefully in order to minimize any additional contamination.
Once the PET bales reach the recycling facility, they are organised, opened up, and broken down into individual bottles. If needed, these PET bottles may go into a pre-washing stage to clear away any existing labels or other contamination.
They are then shredded and ground into flakes of plastic. This is where the value of the recovered material can be determined as the purity of the flakes is monitored. Subsequently, these flakes are separated by type and color, cleared from remaining contaminants, and subjected to deep cleaning. Once completed, the clean plastic makes its way into one of multiple mixing silos inside of which the plastic is homogenized to ensure consistency.
An example of such a recycling facility can be found at Lavergne, a North American high-quality post-consumer recycled (PCR) resin producer. Lavergne has what they call Plastic Care Centres, where post-consumer plastics, like PET, undergo the processes mentioned above in a way that retains their quality and turns them into valuable PCR material for use in engineering applications.
In order to create resins that can be reintroduced into the production processes and be tailored for customer demands and applications, Lavergne has Mixing Additives Centres, where they develop formulations that include the recycled base polymer and useful additives. These additives can ensure proper rebuilding of the molecular chain so that the resin meets the required specifications, such as color matching quality, and maintains its intrinsic quality.
The final stage of the recycling process takes place at what Lavergne calls the Reactive Compounding Centre. The base polymers are melted and blended with the additives to form a compound that undergoes an extrusion process and is then pelletised. Here, melt filtering can be vital as it can help purify the material from any non-melting contaminants that may have managed to reach this phase. To ensure high quality, every step is monitored, and every batch is tested in Lavergne’s certified quality testing laboratory.
After understanding the “what, why, and how” of recycling PET, one question remains: How sustainable is rPET? In other words, how much of a positive effect does it have on our efforts towards sustainability? Well, the answer is not as easy as one might think.
Of course, rPET is one obvious solution to PET’s contribution to the waste crisis and an effective factor in carbon reduction and environmental preservation. In fact, a study has shown that rPET can lead to a reduction in greenhouse gas (GHG) emissions by more than 79% compared to virgin PET. Recycling PET can also help minimise ocean-bound PET waste, which is extremely toxic to the ecosystem both as macro-sized plastic waste and broken-down, microplastic waste.
Yet, the availability of post-consumer recycled PET materials remains a challenge to overcome, not to mention the awareness and demand for recycled products. That is why companies like Lavergne are dedicated to increasing the availability and awareness of high-quality recycled plastic resins.
Lavergne’s mission to provide sustainability-committed customers with a transition to circular plastic has propelled them to effectively reshape the supply chain of plastics on a large scale. In addition to rPET, they offer other 100% PCR base polymers, including rPP, rPC, rHIPS, and rABS. Today, Lavergne has partnered with Matmatch to support engineers and product developers by promoting their recycled plastic materials on the platform and offering their expertise and technical support. Matmatch users can easily search, compare, and examine the materials’ properties and sustainability features.
Visit the Lavergne supplier profile for more information and get in contact with them directly.
Lavergne offers high-quality 100% PCR plastic resins, namely rPET, rPP, rABS, rPC, and rHIPS, via its innovative proprietary technologies developed for processes of separation, decontamination, homogenization, resin formulation, and reactive compounding.
Get in touch with Lavergne for more information.