Context for Readers
This article focuses on a material-level comparison between ECONYL® and REPREVE®. If you are building or scaling a sustainable swimwear brand and want a broader, end-to-end framework—covering material strategy, compliance requirements, supplier verification, and long-term sustainability positioning—you may want to start with our core pillar guide:
→ Sustainable Swimwear: A Complete Guide for Brands in 2025
This comparison piece is designed to complement that pillar by helping you make more precise fiber-level decisions.
Sustainable swimwear materials are increasingly important as brands face higher expectations for environmental transparency, performance reliability, and validated recycling claims. This article provides an evidence-based comparison of ECONYL® (regenerated nylon 6) and REPREVE® (recycled polyester), focusing on supply chain inputs, environmental impacts, durability considerations, certifications, and market implications. It is written for product developers, sourcing teams, and sustainability strategists seeking a technically grounded framework rather than marketing-driven narratives.
1. Executive Summary
ECONYL® offers higher circularity potential through chemical depolymerization of nylon waste, while REPREVE® provides cost-efficient recycled polyester with strong traceability systems. Both materials enable lower-impact swimwear, but they differ in:
Feedstock: ECONYL® uses nylon waste (e.g., fishing nets, carpets); REPREVE® uses PET bottles and textile waste.
Circularity: ECONYL® is chemically recyclable back into virgin-equivalent nylon; REPREVE® is mechanically recycled with more limited closed-loop potential.
Durability: REPREVE® generally performs better in chlorine and UV stability; ECONYL® maintains strong elasticity but may degrade faster under heavy chlorination.
Cost: ECONYL® typically sits at a premium price point due to energy-intensive depolymerization, while REPREVE® offers lower material costs.
Brand Positioning: ECONYL® is widely perceived as premium and circularity-driven; REPREVE® as accessible and high-volume sustainable polyester.
2. Methodological Framing & Limitations
This comparison is based on publicly available process descriptions, LCA-reported figures from referenced industry sources, and observed performance characteristics from textile suppliers. Because this article does not include independent laboratory testing (e.g., chlorine aging, UV exposure cycles, tensile retention curves), it avoids absolute claims and provides framing based on typical performance ranges reported in supplier documentation. Brands should corroborate with fabric-level test reports (e.g., ISO 105-E03, ISO 105-B02, ASTM D2594) before finalizing material choices.
3. Material Origins & Production Pathways
3.1 ECONYL® (Regenerated Nylon 6)
Feedstock for ECONYL® is sourced from post-consumer and post-industrial nylon, including:
Discarded fishing nets
End-of-life carpet fluff
Nylon-6 industrial waste streams
Simplified production flow:
Waste collection and global consolidation
Sorting and preprocessing
Depolymerization of polyamide 6 waste to caprolactam
Repolymerization into virgin-equivalent nylon-6
Chip extrusion and yarn spinning
Depolymerization enables molecular-level recycling, producing material that is functionally similar to virgin nylon-6.
3.2 REPREVE® (Recycled Polyester)
REPREVE® uses PET-based waste as its primary feedstock, including:
Recycled plastic bottles
Ocean-bound plastics
Post-consumer and post-industrial textile waste
Yarn waste from industrial processes
The material is mechanically recycled into chips and extruded into polyester fibers. Traceability is supported by proprietary FiberPrint® tracer technology and U-TRUST verification, which helps brands validate recycled content claims.
4. Environmental Impact Assessment
4.1 Energy & Emissions
ECONYL®
Reported process benefits for ECONYL® compared with conventional nylon 6 production include:
Approx. 16.2 GJ energy savings per metric ton of regenerated caprolactam
Avoidance of around 4.1 t CO₂ per metric ton versus virgin nylon
Roughly 1.1 t of waste diverted from landfill per metric ton of output
These figures represent modeled process savings and can vary by region, energy mix, and logistics. They should be interpreted as indicative, not universal constants.
REPREVE®
Mechanical recycling of polyester generally yields lower environmental impacts than virgin PET production. Reported comparative benefits for REPREVE® production include:
67% reduction in freshwater use
76% reduction in fossil resource consumption
66% reduction in non-biogenic resource use
Because PET bottle collection systems are relatively mature, REPREVE® benefits from a stable, large-scale feedstock stream.
4.2 Circularity & End-of-Life
ECONYL®: can be chemically recycled multiple times with limited loss of performance, supporting a more clearly defined circularity model for nylon-6.
REPREVE®: relies on mechanical recycling, which is subject to polymer chain degradation over multiple cycles. Long-term closed-loop recycling is possible but often constrained without chemical recycling infrastructure.
Both materials significantly reduce waste inputs relative to virgin counterparts, but ECONYL® provides a more explicit circularity pathway for nylon 6 systems.
5. Durability & Performance
5.1 Chlorine and UV Resistance
Typical supplier and industry data suggest the following tendencies for swimwear applications:
Property | ECONYL® | REPREVE® |
|---|---|---|
Chlorine resistance | Moderate | Excellent |
UV stability | Moderate | Excellent |
Important: these are general patterns, not guarantees. Actual performance depends strongly on:
Fabric construction (e.g., knit density, yarn count, presence and percentage of elastane)
Chemistry of dyes and finishes
Pool conditions (chlorine concentration, pH, temperature)
Exposure duration and care behavior (rinsing, drying conditions, etc.)
Brands should rely on laboratory-tested reports (e.g., ISO or ASTM standards) for final durability claims rather than generic fiber-level statements.
5.2 Elasticity & Handfeel
ECONYL®: maintains the elasticity, drape, and smooth handfeel typical of high-quality nylon-6, often favored in premium and fashion-forward swimwear.
REPREVE®: provides reliable dimensional stability and durability; handfeel can range from soft to slightly firmer depending on construction and blends used.
Final comfort and performance characteristics are determined at the fabric and garment level, not solely by the base fiber.
6. Cost Analysis
Indicative material cost ranges (subject to change by supplier, region, volume, and finish):
Material | Approximate Cost Range |
|---|---|
Regenerated polyamide (ECONYL®) | ~USD 1.80–3.00/kg |
Recycled polyester (REPREVE®) | ~USD 1.10–2.50/kg |
The premium on ECONYL® reflects the complexity and energy usage of depolymerization and repolymerization processes. REPREVE® tends to be more cost-efficient due to mature PET recycling streams and large-scale bottle collection infrastructure.
When building a cost-benefit model, brands should consider:
Fiber price volatility and long-term contracts
Fabric conversion costs and minimum order quantities
Durability (and resulting product lifespan) impacts on cost-per-wear
Potential price uplift achievable through sustainability positioning
7. Certification Landscape
Both ECONYL® and REPREVE® are typically available in fabric constructions that carry third-party certifications, such as:
GRS (Global Recycled Standard) – validates recycled content and supply chain practices.
RCS (Recycled Claim Standard) – verifies recycled raw material inputs.
OEKO-TEX® Standard 100 – confirms that fabrics are tested for harmful substances and are safe for skin.
It is crucial to note that these certifications are often fabric-specific, not automatically conferred by fiber brand names alone. Brands must verify certificates (scope, validity, and holder) with their fabric suppliers.
8. Market Perception & Brand Positioning
In the current market landscape:
ECONYL® is widely associated with premium, circularity-driven lines and collaborations. It signals investment in higher-end sustainability and design.
REPREVE® is closely linked to large-volume, accessible apparel, emphasizing bottle recycling, traceability, and measurable impact metrics.
Consumer research consistently shows growing demand for:
Clear communication of recycled content percentages
Verification via third-party certifications
Transparent storytelling about sourcing and end-of-life options
Brands should balance simplified messaging (for shoppers) with accurate, non-exaggerated claims (to avoid greenwashing and regulatory risk).
9. Material Selection Framework for Brands
9.1 When to Prioritize ECONYL®
ECONYL® is a strong candidate if your brand aims to:
Position collections as premium or luxury-oriented
Highlight circularity and waste-to-resource narratives
Leverage the elasticity and drape of nylon-6 for form-fitting silhouettes
Align with design-led, storytelling-focused capsule collections
9.2 When to Prioritize REPREVE®
REPREVE® is often the better fit if your brand focuses on:
Cost-efficient sustainability at scale
High-frequency use in chlorinated pools and strong UV exposure
Large collections where traceability and bottle-to-fiber storytelling are key
Performance-oriented styling, such as training or athletic swimwear
9.3 Blended Portfolio Strategy
Many brands benefit from a dual-material strategy:
Use ECONYL® in limited-edition or premium lines focused on circularity, design, and storytelling.
Use REPREVE® in core, high-volume styles that prioritize durability, accessibility, and strong sustainability credentials.
This approach allows you to serve both premium and price-sensitive segments while maintaining a consistent sustainability narrative.
10. Frequently Asked Questions
10.1 Is ECONYL® infinitely recyclable?
ECONYL® nylon 6 is chemically recyclable, which means it can, in principle, be depolymerized and repolymerized multiple times. However, “infinite” recyclability is constrained in practice by collection systems, contamination, sorting efficiency, and economic factors. Brands should avoid absolute claims and instead frame ECONYL® as part of a scalable circularity solution for nylon 6.
10.2 Do ECONYL® and REPREVE® eliminate fossil fuel dependence?
No. Both materials reduce reliance on virgin fossil resources by reusing existing plastics and nylon waste. However, they still require energy inputs, and in many regions that energy is at least partly derived from fossil fuels. Claims such as “fossil-free” or “no fossil fuels” are not accurate unless supported by verified renewable energy use across the supply chain.
10.3 Which material lasts longer in chlorinated pools?
Polyester-based fabrics (including those made with REPREVE®) generally show stronger resistance to chlorine and UV exposure than nylon-based fabrics (including ECONYL®), particularly in prolonged or intensive pool use. That said, individual fabric constructions can perform quite differently. Always request and review standardized test data from fabric suppliers.
10.4 Can ECONYL® and REPREVE® be mixed within one product line?
Yes. Many brands successfully use both materials across different styles in the same collection. For example, ECONYL® may be used in premium, fashion-led designs, while REPREVE® is used in performance-driven or entry-price-point swimwear.
10.5 Are ECONYL® and REPREVE® safe for sensitive skin?
Both materials are available in fabric constructions that meet OEKO-TEX® Standard 100 or equivalent chemical safety standards, meaning they are tested for harmful substances. Sensitive-skin suitability, however, also depends on dyes, finishes, and garment construction, so always confirm at the fabric level.
Conclusion
Both ECONYL® and REPREVE® offer substantial benefits over virgin nylon and polyester for brands developing sustainable swimwear. ECONYL® provides strong circularity credentials and premium material characteristics, while REPREVE® delivers cost-efficient sustainability with robust traceability and enhanced chlorine/UV durability.
The most effective strategy is to base fiber selection on:
Independent durability and performance testing
Life cycle assessment (LCA) data where available
Brand positioning and target consumer segments
Supply chain resilience, scalability, and cost structure
By combining rigorous testing with transparent communication, brands can leverage ECONYL® and REPREVE® to build swimwear collections that are both high-performing and genuinely more sustainable.