Sustainable swimwear fabric beyond recycled nylon

ECONYL and similar recycled nylon yarns became the standard answer to the sustainable swimwear question around 2018 and have remained there ever since. They are a genuine improvement over virgin nylon in terms of resource use, and the performance characteristics are now well understood. But a growing number of smaller brands and fabric developers are asking what comes after recycled nylon. And the answers are more varied than expected.

Why recycled nylon has limits ¶

Recycled nylon is made primarily from post-consumer waste. Fishing nets, carpet fibre, industrial plastic. The recycling process is energy-intensive, and the resulting yarn, while better than virgin nylon in lifecycle terms, is still a synthetic that does not biodegrade at end of life. The chlorine resistance and stretch recovery that make nylon ideal for swimwear are properties that also make it persistent in the environment.

This is not an argument against recycled nylon. It remains a better choice than virgin synthetic for most applications. But it is a reason to take seriously the research being done on alternatives, particularly for brands that want to move further along the sustainability curve.

Bio-based alternatives in development ¶

The most promising category is bio-based polyamide, produced from plant-derived feedstocks rather than petroleum. Several European and Japanese fabric developers have been working on versions that match the stretch and chlorine resistance of conventional nylon. The results so far are encouraging in laboratory conditions but have not yet been tested at scale across multiple seasons of real-world use.

A separate line of development involves natural fibres treated for water resistance. Merino wool and linen have both been explored, with limited success for swimwear specifically. The stretch requirements of a fitted bikini are difficult to meet with natural fibres alone, and blends that add synthetic content to achieve stretch tend to reintroduce the end-of-life problem.

What this means for buyers now ¶

For most readers, the practical answer for the next two or three seasons is still recycled nylon for performance swimwear, with the caveat that the brand's overall production practices matter as much as the fabric choice. A swimwear piece made from recycled nylon but produced in poor conditions is not straightforwardly a better choice than a well-made piece in conventional fabric that will last ten years.

The bio-based alternatives are worth watching. We will cover them in more detail in Issue 16 when we have more data on real-world performance.

The sustainable fabric question in swimwear does not have a clean answer yet. Recycled nylon is the current best available option for most applications. The of materials is being developed, and the results over the next few years will be worth following closely.