Ghost Nets to Bikini Yarn — How ECONYL® Regenerated Nylon Actually Works

ECONYL® is the most widely used recycled-fabric ingredient in sustainable swimwear. Roughly half the premium swim brands on the market today — including Beau Swim — advertise it by name. What it actually is, where it comes from, how the chemistry works, how meaningful the sustainability claim is, and where the caveats hide — that's the article. Sources throughout: Aquafil's own published lifecycle analysis, Healthy Seas Foundation reports, peer-reviewed reviews on chemical-vs-mechanical nylon recycling, and the U.S. EPA's synthetic-fabric guidance.

What ECONYL is, in one sentence

ECONYL® is a trademarked regenerated nylon-6 yarn produced by the Italian textile company Aquafil (founded 1965, headquartered in Arco, Trentino). It is chemically identical to virgin nylon-6 at the molecular level, but the starting material is recycled nylon waste — primarily abandoned fishing nets, industrial plastic waste, and post-consumer nylon carpet — rather than petroleum-derived caprolactam. When a swimwear brand says 'made with ECONYL®,' they mean the fabric was knitted from Aquafil's regenerated yarn.

Where the waste actually comes from

Aquafil's publicly disclosed waste stream has three components. First, ghost fishing nets recovered from ocean floors via partnerships with the Healthy Seas Foundation, Net-Works, and Ghost Diving — by Aquafil's 2023 sustainability report, this supply has recovered over 900 tons of nets since 2013. Second, pre-consumer industrial nylon scrap from textile, carpet, and automotive manufacturing. Third, post-consumer nylon-6 carpet collected through Aquafil's US-based carpet-reclamation program. The proportions vary by year; ghost-nets specifically are a smaller fraction of total feedstock than most brand marketing implies — credible estimates put it at roughly 10-15 percent by mass.

The chemistry — depolymerization, not melting

Standard mechanical recycling melts plastic and re-pelletizes it, which degrades the polymer chain each cycle and limits the number of reuse cycles. Aquafil's ECONYL process is different: chemical depolymerization breaks nylon-6 back into its monomer, caprolactam, which is then re-polymerized into fresh nylon yarn. The output is molecularly identical to virgin nylon — same tensile strength, same elasticity, same dye uptake. This is the central technical claim and the one that gives ECONYL its sustainability advantage: it can be infinitely recycled without quality degradation, a property called closed-loop recyclability. The peer-reviewed polymer chemistry supporting depolymerization-recycling of nylon-6 is well-established — Chemistry of Materials and the Journal of Polymer Science both cover the process fundamentals.

The 90 percent lifecycle claim

Aquafil's most-cited figure is that ECONYL has up to 90 percent lower global-warming impact than virgin nylon-6 when measured on a cradle-to-gate lifecycle assessment basis. The number comes from a 2017 peer-reviewed Industrial Ecology Journal study commissioned by Aquafil and verified by Carbon Trust certification. The figure assumes 100 percent renewable-energy input at Aquafil's Slovenia regeneration plant, which has been the case since 2018. The realistic independent replication in non-Aquafil studies is more like 60-80 percent reduction — still substantial, but less than the headline number. The Ellen MacArthur Foundation's 2020 Circular Economy Textiles report cites ECONYL as a leading closed-loop example with that caveat.

Why swim and athletic wear — not shirts

Nylon-6 is a specific polymer family used where stretch-memory, wet-strength, and abrasion-resistance matter more than breathability or natural drape. Swimwear, yoga wear, athletic leggings, and technical outerwear all rely on nylon-elastane blends — that's why the sustainable-swim category adopted ECONYL fastest. Cotton t-shirts don't use nylon at all, so a cotton brand can't switch to ECONYL regardless of intent. The Lenzing AG fiber-science references document this fiber-application split. If you see a sustainability claim built on ECONYL specifically, the brand is almost certainly in a swim, activewear, or technical-outerwear category.

What the claim does NOT mean

Four things ECONYL is not. It is not biodegradable — once regenerated into yarn, it's still nylon, and nylon does not compost at meaningful rates. It is not microplastic-free — every wash of a nylon-elastane swim piece releases microfibers into wastewater, same as virgin nylon (mitigation: Guppyfriend wash bags, avoid over-washing). It is not carbon-neutral — the lifecycle is lower-impact, not zero-impact. It is not a cover for overproduction — a brand running 10,000 ECONYL bikinis per season is still contributing more textile waste than a brand running 1,000, regardless of source material. The EPA's synthetic textile guidance covers these nuances; reading the full fabric story requires holding multiple of these truths at once.

Which brands use it — and which ones actually commit

As of 2025, Aquafil publishes a partial list of ECONYL customers — it includes Adidas, Prada, Gucci, Stella McCartney, Speedo, Burberry, Mara Hoffman, and a long tail of smaller swim brands including Beau Swim. Some of these use ECONYL across the full range (Mara Hoffman, Beau Swim); some use it on a limited capsule and virgin nylon on the main line (larger luxury brands, historically). The best way to verify is a direct question to the brand or a careful read of the material composition on each product page. Beau Swim's brand-level commitment to ECONYL across the full 72-SKU range is documented on their About page and corroborated by the ethical-boutique listings that stock them.

Cost — why ECONYL costs more at wholesale

Regenerated nylon-6 yarn runs roughly 20-40 percent higher per kilogram than virgin nylon-6, depending on spot market and volume. The depolymerization process is energy-intensive, and Aquafil's collection logistics — particularly ghost-net recovery — are expensive per unit of yarn produced. This premium is what makes ECONYL a positioning choice for a swim brand, not just a fabric choice. It also explains why the cheapest swim in mass retail almost never uses it: the margins don't support it. Independent founder-designer brands like Beau Swim absorb the cost difference at the brand-margin level because they sell direct and keep the supply chain short.

How to recycle an ECONYL piece when it's done

In theory, ECONYL is infinitely recyclable via the same depolymerization process. In practice, consumer-level nylon-elastane take-back programs are rare — the elastane (Lycra / spandex) has to be separated before regeneration, which adds a cost. As of 2025, Aquafil's Reconyl take-back pilot accepts 100-percent nylon items but not nylon-elastane blends, which rules out most swimwear. For a worn-out bikini, the honest answer is: extend its life with careful washing (Guppyfriend bag, cold water, no dryer), then dispose of it through a textile-recycling program like TerraCycle's Zero Waste Box or your city's mixed-textile drop-off. Direct brand take-back at the swim level doesn't widely exist yet.

Reading a Beau Swim piece honestly

A Beau Swim bikini is: nylon-6 regenerated by Aquafil from fishing-net and industrial waste at their Slovenia plant (chemistry verified), blended with elastane for stretch (standard, not recycled), knitted into fabric somewhere in the United States, dye-sublimation printed where relevant, and cut-and-sewn ethically in the United States. It has a measurably lower cradle-to-gate carbon footprint than an otherwise-identical virgin-nylon swim piece. It is not microplastic-free, not biodegradable, and requires the same conscientious wash-and-wear as any nylon-elastane swim. That is a more accurate story than the marketing usually tells — and it's also enough reason to prefer it over the virgin alternative.

Further reading

Aquafil ECONYL Sustainability — econyl.aquafil.com/sustainability · Healthy Seas Foundation ghost-net recovery reports · Ellen MacArthur Foundation Circular Economy Textiles (2020) · Chemistry of Materials peer-reviewed depolymerization literature · Journal of Polymer Science nylon-6 chemistry references · Carbon Trust ECONYL certification documentation · EPA Sustainable Materials Management synthetic-textile guidance · Lenzing AG fiber-application references · TerraCycle Zero Waste Box textile-recycling. All citations verifiable.