What you need to know about pre- and post-consumer recycling

Take a quick look around your household, and you will realize that daily life would be hard to imagine without plastics. It’s in the packaging that keeps our food fresh, in the clothes we wear, in our furniture, carpets and countless other everyday objects. But the success of plastics – their light weight and durability – are also the material’s biggest problem. At the end of their usage, plastics typically end up as waste, remaining in the environment even when they are no longer in use.

In the currently dominant, linear economic model, we take materials from the Earth, make products from them, and we eventually dispose of them as waste. In contrast, the circular economy model aims to use closed-loop production to keep resources in play for as long as possible. In this model, there is no more plastic waste, or at least, waste plastics should be valorized again as much as possible. This also means that already in the design phase, attention should be paid to the way products can re-enter the loop at the end of their lifetime.

Eliminating waste is one of the most important principles of the circular economy, but there are different paths to get there.

• Post-consumer recycling: This is probably the best-known form of recycling. It refers to material generated by households or other end-users which can no longer be used for its intended purpose. Think of PET bottles which are recycled by consumers every day, sorted by recycling facilities, and processed into something new.
• Pre-consumer recycling: This is also called post-industrial recycling. It refers to the reclamation of waste that is created during the manufacturing process before it gets delivered to the consumer. Think of scraps from paper production or, closer to the carpet industry, residual materials from the production of virgin nylon.

The distinction between pre- and post-consumer recycling naturally results in the inevitable question: which recycling method is best? Today, post-consumer recycling gets the bulk of the attention. The definite answer to this question however is not so straightforward. To evaluate both approaches, we need to look at the different recycling technologies that are typical of both pre- and post-consumer recycling.

Post-consumer recycling is mostly a thermo-mechanical process. Plastics are shredded, melted and granulated. It’s a fairly low-investment, low-impact approach that can cover large volumes of plastic waste. The downside of this method is that it works with waste that is often polluted from being used, or mixed with other materials, which makes it more difficult to separate into mono-materials with the same original quality. As a result, the application range of post-consumer recycled content is often limited. In addition, the success of post-consumer waste recycling heavily depends on the available infrastructure for collecting, sorting, pre-treating and reprocessing materials.

Pre-consumer recycling typically relies on chemical recycling. Since pre-consumer waste is not polluted by use, it is much purer and closer to virgin material. In addition, chemical recycling can break up plastics down to their basic, high-quality building blocks. These can be used for new applications and have the potential to be used in an infinite recycling system. Although more energy-intensive, chemical recycling is gaining momentum in the carpet industry. EqoCycle PA6 yarns for example use no less than 75% recycled content, based on recycled and regenerated PA6 industrial waste.

In the carpet industry, eco-design is the new black. The idea here is that recyclability should already be taken into account from the start, right at the product’s design phase. Not an easy job for sustainability engineers, because in order to be recyclable, pre- and post-consumer waste needs to tick a lot of boxes (separability, use of mono-materials, cleanliness, etc.).

Choosing the right virgin material in light of its recyclability has now become crucial. A material like Polyamide 6 (PA6) for example, holds great potential in the production of yarns, because it can be infinitely recycled and reused in various applications. PA6 is produced by polymerization of caprolactam, an organic compound. PA6 waste can then be depolymerized again into its raw material caprolactam. This can be used to make new recycled granulate and in a next step PA6 yarns with the same chemical and performance characteristics as those produced from fossil sources.

There are currently many certification systems to prove the use of genuine recycled material in manufacturing. The most important labels to look out for are the Global Recycled Standard (GRS) and ISCC Plus, which have established itself as the leading standard in the plastics industry.

 

The recycling discussion is far from over. The quest for innovation is still in full force. One thing is certain: to successfully reduce waste on landfills and in incineration, the industry will need to consider all possible waste streams. And we will need to keep our eyes open for new ways to reduce, reuse and recycle materials. Both post-industrial and post-consumer recycling will be valuable and will play an important role in driving the circular economy forward. This will require a concerted effort from all players in the value chain.