As is often the case, our audience had more questions than we had time to cover, so we reached out to the Aquafil team after our talk for some additional insight. A recording of the event is included here for context.
Will there be an additive available in the near future that will be able to help to fight viruses?
As of today, many companies are studying additives with antibacterial and antiviral properties. Anyway, it seems a long and challenging pathway, since viruses are very sneaky to fight against.
Is there a site that tells consumers around the world where to send their used nylon clothes and carpets to be recycled?
In the last years, Aquafil made a great effort to build a supply chain to recover the products at the end of their life, both from their customers and from other companies specialized in that. Many Aquafil customers have developed programs to take back their products at the end of their life, so it may be a good idea to check the website of your clothes or carpets producer. Aquafil itself has facilities dedicated to collect back the carpets for the California and Phoenix area (i.e., Aquafil Carpet Recycling).
Is this not just chemical recycling? If yes, why just do it with Nylon and not do it with PET?
Nylon 6 has special properties that make the chemical recycling easier than other polymers. Something is starting to be done with PET all around the world, but it is still at an early stage.
Can the ECONYL process be used to recycle glass-filled nylon?
Theoretically yes, practically it is very difficult, since it is very difficult to handle the glass fiber because of its physical behavior.
How do you handle color of the recycled materials? Does the color get removed during the depolymerization process?
The secret is the step back to caprolactam (our raw material). Colors and other additives cannot be removed from nylon, but it becomes easier to separate them from the caprolactam, because it leaves the depolymerization reactor as a vapor, leaving all colors and additives behind.
What’s the main acid used for the depolymerization? Assuming the chemical pathway is hydrolysis based.
Yes, it is hydrolysis based, and different catalysts can be used, both acid and alkaline. We have chosen the most efficient, that is food grade phosphoric acid.
As you depolymerize the material, how is it possible for a customer to know that they have ECONYL and not virgin material?
There is no way to tell if the product is made from ECONYL® caprolactam or fossil based caprolactam by just analyzing the product, since their quality is exactly the same. For our products we have an EPD (Environmental Product Declaration), which is based on the Life Cycle Assessment (LCA), according to the ISO 14040. An independent company made LCA study on our ECONYL® process compared to the traditional process in the same boundaries.
The US carpet guys use mostly PET (soda bottles) and some PP. (probably because it easier to reclaim this material in the states) Just wondering what are the major differences between a material like Aquafil and recycled PET?
PET and PP have a wider market also because of their lower price. Nylon has better properties, so it is the preferred choice where durability or mechanical resistance are required (i.e. in the contract sector). The differences between ECONYL® nylon and recycled PET, when it comes to their properties, are the same between fossil-based nylon and fossil-based PET.
Do you receive waste directly from waste management company?
Yes, we have different agreement with waste collectors and management companies all over the world. Long term partnerships mean that we can be sure to receive good, nylon 6 waste materials constantly to feed the process.
What textile mills are you working with that would have ECONYL available for producing fabric?
There are different, depending on the applications. Fabric for upholstery is still in the developing stage but please be in touch with us and we can start the conversation.
How likely do you feel it is that eventually in the future major fashion brands and manufacturing companies will take on more sustainable practices like ours?
In a way they will need to do it to remain in business, either because consumers will require more extensive focus on these processes or because of changing regulations in the industry.
I am curious about emission during depolymerization, how to ensure that less or no GHG being emitted in the process?
For our products we have an EPD (Environmental Product Declaration), which is based on the Life Cycle Assessment (LCA), according to the ISO 14040. An independent company made LCA study on our ECONYL® process compared to the traditional process in the same boundaries.
How do you efficiently and effectively connect with local fishermen and other sources to collect the raw materials?
It’s different for each type of waste material and it’s also different depending on countries and how waste is collected. Specifically, for fishing nets we work with the aquaculture industry recovering their old nets. We also founded, together with another business and an NGO, an initiative called Healthy Seas, a journey from waste to wear. With this initiative, volunteer divers recover ghost nets from the ocean.
The carpet stream of waste is mainly in the US with two carpet recycling facilities and collection and sorting facilities in Phoenix and in Sacramento.
Does shredding of the nylon releases micro particles in the air or is there any other system which is more environmentally friendly?
Can this process be used for N66?
In all our process there is no release of micro particles in the air, since the emissions in all operations are collected and treated. Therefore, not only micro particles, but also no other pollutant is released during the shredding of nylon.
The ECONYL® process can be used only for nylon 6 and not for nylon 66, which is obtained by combining together two different monomers and not just one.
You mentioned injection molded, in packaging a big challenge is volume for small brands. Small brands cannot meet the volume demands in packaging. What is industry doing to help this change happen, this applies to fabric too?
How are contaminants managed or affected in this process? for example, flame retardants or PFAS treatments? Do these contaminants make recycling more difficult?
The presence of contaminants, in general, has a negative impact on the process. For this reason, it is important to make a first treatment on the materials before the chemical step. If the level of contaminants is out of specification (either because they are too much or because they are particularly dangerous), the material is not accepted for the ECONYL® process. In fact, we analyze samples of all the batches of waste material we receive. In the meantime, EU and other regulations have banned some critical additives, such as PFAS and halogenated flame retardants.
How do you ensure your recycling and production factories emit as little carbon emissions as possible, i.e., are you using renewable energy at the source of production?
Yes, emissions are decreased by recurring to renewable, such as solar and hydroelectric. All the data are publicly available on the Sustainability Report.
Can the nylon be extracted from a multi-material object? Or does the nylon have to be fully separated from other materials before being processed?
Multi-material objects are more difficult to handle, since it is necessary to make a first step to remove as much as possible all the other materials and obtain a nylon 6 concentration as higher as possible. Aquafil started to study this topic long ago and now has a patented system to separate nylon 6 from the other components of the carpet.
Anyway, the real game changer will be the eco-design, that means to design the product with the end in mind: this can be done by creating mono-material objects, or multi-material objects where the separation is easier: Aquafil is always open to the collaboration with its partner on this topic.
What are the difficulties you face while separating two materials?
It is difficult to answer shortly, since there are too many materials that need to be removed from nylon, and for any material the methodologies are different. Probably the most challenging is the separation between nylon 6 and nylon 66.
In which way are the dyes eliminated in this recycling process?
The secret is the step back to caprolactam. Colors and other additives cannot be removed from nylon, but it becomes easier to separate them from the caprolactam, because it leaves the plant as a vapor, leaving all colors and additives behind.
We would like to say thank you again to Guilio and the whole Aquafil team for sharing their time, expertise, and process with us all.