Development of a Multi-Dimensional Framework for Interpreting the Sustainability of Textile Materials

Abstract

Sustainability assessment of textile materials has traditionally relied on origin-based classifications and indicator-driven life cycle assessment (LCA), often treating sustainability as an inherent or material-intrinsic property. However, materials sharing similar biological origins or “bio-based” labels frequently exhibit substantially different sustainability outcomes when processing pathways, composite structures, and end-of-life (EoL) compatibility are taken into account. To address this limitation, this study develops a qualitative, multidimensional analytical framework that conceptualizes textile material sustainability as a pathway-dependent and system-mediated outcome rather than an inherent material attribute. The framework integrates four interrelated dimensions—renewability, process sustainability, EoL options, and material source—derived from a structured review of academic, policy, and technical literature. To demonstrate the analytical scope and internal logic of the framework, a selected set of 65 innovative textile materials was systematically analyzed using a three-tier qualitative coding scheme (favorable, conditional, and unfavorable) under conservative data validation criteria. The analysis shows that sustainability performance is primarily shaped by pathway configurations—particularly processing intensity, binder chemistry, and EoL compatibility—rather than material origin alone and that similar bio-based materials can exhibit fundamentally different sustainability profiles depending on these factors. By reframing sustainability from a material-centered perspective to a pathway-oriented and system-based perspective, the proposed framework provides a structured basis for integrating material innovation, process design, and end-of-life planning in sustainability-oriented textile research and development and establishes a conceptual foundation for future empirical and quantitative extensions.

1. Introduction

As global demands for sustainability continue to expand, structural transformations are occurring across a wide range of industrial sectors. Among them, the textile and apparel industry is widely recognized as one of the most resource-intensive and environmentally impactful industries [1,2], requiring substantial inputs of energy, water, and raw materials throughout its life cycle.

The textile life cycle—spanning fiber production, dyeing, garment manufacturing, use, and disposal—constitutes a continuous system of resource consumption and environmental burden. Consequently, the fashion and textile sector is estimated to account for approximately 5–10% of global greenhouse gas emissions [2]. This indicates that environmental impacts arise cumulatively across interconnected life-cycle stages—including raw material extraction, manufacturing, consumer use, and end-of-life treatment—rather than from isolated processes, thereby requiring system-level analytical approaches.

In this study, environmental performance is interpreted not as a single indicator but as an aggregated outcome of multiple environmental impact categories arising across the textile life cycle, including resource consumption (e.g., energy and water use), emissions (e.g., greenhouse gases and pollutants), chemical-related impacts, and end-of-life outcomes such as waste generation and recyclability. These impacts are shaped by interactions among material composition, processing pathways, and system conditions, thereby requiring a system-level and pathway-oriented mode of analysis.

In particular, the extensive use of petroleum-based synthetic fibers and conventional cotton cultivation has intensified environmental pressures through microplastic emissions, excessive water consumption, and soil and water contamination caused by agrochemicals and processing chemicals [3,4,5]. The rapid expansion of fast fashion has further shortened production and consumption cycles, increasing the proportion of garments discarded shortly after purchase, many of which ultimately end up in landfills or incineration facilities [6,7]. These dynamics indicate that upstream decisions—such as fiber selection, material composition, and processing methods—directly constrain downstream environmental outcomes, especially with respect to end-of-life (EoL) pathways.

Against this backdrop, circular economy principles increasingly highlight material strategies aimed at improving sustainability—such as renewable inputs, recyclability, and alternative end-of-life options—as key enablers of systemic transformation in the fashion and textile sector [8,9,10]. At the policy level, life-cycle-based assessment and disclosure frameworks—including the EU Green Deal, ISO 14040/44 standards for life cycle assessment (LCA), the Corporate Sustainability Reporting Directive (CSRD), and the Product Environmental Footprint (PEF) methodology—are rapidly expanding [11,12,13,14]. These frameworks institutionalize sustainability evaluation through standardized indicators, yet they primarily assess environmental performance at discrete stages and do not fully capture structural interactions among material composition, processing systems, and end-of-life conditions.

In parallel, sustainability research in the textile sector has expanded rapidly, with LCA-based environmental assessments and recycling-oriented circular strategies emerging as dominant research streams. Gonzalez et al. [3] conducted a cradle-to-gate life cycle assessment comparing natural and synthetic fibers and demonstrated that environmental impacts differ significantly across fiber types under defined assessment conditions, indicating that sustainability performance cannot be inferred solely from material origin. Mehmeti et al. [4] examined organic and conventional cotton cultivation systems and showed that environmental outcomes at the agricultural stage are strongly influenced by region-specific practices—such as irrigation methods, fertilizer and pesticide application, and yield levels—as well as input conditions including water use, energy consumption, and agrochemical inputs, thereby demonstrating that sustainability performance depends on specific production contexts rather than generalized material categories. Sandin and Peters [15] reviewed textile reuse and recycling systems and found that environmental benefits depend on system configurations, including reuse rates and substitution assumptions—defined as the extent to which reused or recycled products replace the production of new garments—rather than being inherently determined by recycling processes themselves.

A review of prior academic and policy literature indicates that the sustainability of textile materials cannot be adequately described using single indicators or isolated environmental metrics. Fadara et al. [16] proposed a sustainability indicator framework demonstrating that environmental, economic, and social dimensions must be evaluated simultaneously, thereby establishing the multidimensional nature of sustainability assessment. Roh [17] analyzed sustainability research in the textile and apparel industry and identified four interrelated dimensions—technological innovation, environmental impact assessment, ethical and institutional factors, and circular strategies—while demonstrating that these domains remain fragmented and insufficiently integrated within existing research structures. Ribul et al. [18] examined recycling pathways in circular textile systems and showed that material circularity depends on interactions between material properties and processing systems across mechanical, chemical, and biological recycling routes.

Existing sustainability assessment approaches and certification systems provide important reference points for evaluating textile materials, particularly in relation to environmental impacts, chemical safety, and production conditions across different stages of textile manufacturing. The EU Ecolabel establishes life-cycle-based criteria encompassing resource use, emissions, hazardous substances, and durability, thereby operationalizing sustainability through standardized environmental indicators [19]. OEKO-TEX^® Standard 100 evaluates textile products based on the presence of harmful substances using predefined threshold values, representing a product-level chemical safety assessment approach [20]. STeP by OEKO-TEX^® extends this evaluation to production systems by incorporating environmental performance, chemical management, occupational safety, and social responsibility at the facility level, thereby shifting the analytical focus toward manufacturing conditions [21].

However, these approaches are treated in this study as comparative benchmarks rather than as primary analytical frameworks. At the policy level, a range of policy frameworks, standards, and guidance instruments developed by the European Commission and UNEP have been widely adopted to support the standardization of sustainability evaluation across the textile value chain [11,12,13,14,22].

Nevertheless, prior studies have shown that such approaches often rely on predefined indicators and fixed system boundaries, which may limit their ability to capture interactions among material composition, processing routes, and end-of-life scenarios. Moazzem et al. [5] demonstrated that life cycle assessment outcomes are highly sensitive to system boundary definitions, particularly in terms of whether key life cycle stages—such as raw material production, manufacturing, consumer use (e.g., washing and drying), and end-of-life treatment—are included or excluded, as different boundary configurations can lead to substantially different environmental impact results. Van der Velden et al. [23] further showed that comparative environmental benchmarking across textile fibers is strongly influenced by methodological assumptions, thereby limiting direct comparability between materials.

Recent reviews on textile recycling technologies have emphasized that both environmental performance and technological feasibility vary depending on material composition and processing pathways, rather than recycling categories alone [24,25].

Similarly, material classification approaches—such as bio-based or recycled categories—often treat sustainability as an intrinsic attribute, thereby overlooking variability arising from system configurations and processing conditions. Eppinger [26] highlighted that classifications based solely on material origin—such as “bio-based” or “recycled”—obscure differences in technological maturity, processing requirements, and actual recovery efficiency, leading to oversimplified interpretations of sustainability performance.

Despite these contributions, existing approaches remain methodologically fragmented, with limited integration of multiple interacting factors—such as material composition, processing pathways, and end-of-life conditions—into a unified analytical framework [12,16,24,27]. Consequently, current approaches are primarily limited to identifying relative environmental performance, without sufficiently explaining the underlying mechanisms that generate differences in sustainability outcomes.

To address this gap, this study proposes a multidimensional analytical framework structured around four interrelated criteria, through which textile material sustainability is reconceptualized as a pathway-dependent outcome arising from interactions among material composition, processing pathways, and end-of-life compatibility within specific system conditions.

2. Methods

2.1. Research Overview

In this study, a qualitative content analysis was conducted based on a wide range of secondary sources, including peer-reviewed academic literature, industrial and technical reports, corporate sustainability disclosures, and policy and standardization documents [11,14,22,28].

The proposed framework is not designed as an assessment model to generate quantitative performance scores or to rank materials in terms of superiority. Rather, it is conceived as a structural analytical tool that enables the comparative interpretation of how different textile materials diverge in their sustainability outcomes through distinct material, process, and end-of-life pathways.

To ensure methodological transparency, the framework is constructed based on predefined analytical criteria derived from prior literature on life-cycle-based assessment and material-driven design approaches [29,30], allowing consistent interpretation across different textile materials.

2.2. Material Selection and Categorization

A total of 65 textile materials were selected for analysis based on the following three criteria:

• materials that are currently commercially available, are expected to reach near-term commercialization, or have demonstrated technical feasibility;
• materials for which sustainability-related information on textile materials is accessible; and
• materials representing a broad range of material origin categories.

To enhance methodological transparency and reproducibility, explicit decision rules were applied during the classification process, following the material selection procedure described above. Specifically, recyclability was classified as “feasible” only when established recycling pathways were available within existing waste-management systems [24,27]; biodegradability was considered “valid” only under empirically demonstrated conditions, as the biodegradation of bio-based polymers depends on specific environmental conditions such as temperature and composting systems [31,32]; and material source classification was assigned based on the primary constituent component rather than nominal or marketing-based descriptions. These rules were consistently applied across all cases to ensure analytical rigor and consistency.

The selected materials should be understood as an analytically representative sample reflecting current technological and industrial trends, rather than a statistically exhaustive inventory. This selection prioritizes the interpretation of diverse sustainability pathways of textile materials across material groups, rather than the generalization of performance claims.

Data sources included peer-reviewed academic articles indexed in Scopus and Web of Science, industrial and corporate sustainability databases (e.g., Lenzing AG [28]), and key policy and standardization documents such as the EU Green Deal, ISO 14040/44 standards, and UNEP’s Global Roadmap for Circular Textiles [11,14,22].

To minimize potential bias associated with brand-driven sustainability claims, priority was given to materials supported by life-cycle-based assessment perspectives as articulated in international standards and peer-reviewed studies [5,22,23].

The classification of the selected textile materials according to their origin and technological characteristics is summarized in the Results section. This classification serves as an analytical basis for examining how sustainability pathways of textile materials are structured across different material types.

It should be noted that the limited availability of standardized and empirically validated sustainability data across emerging textile materials reflects a broader structural condition of the field rather than a limitation specific to this study [16,24,27]. This constraint reinforces the need for an analytical framework capable of systematically interpreting heterogeneous and non-uniform data environments.

2.3. Framework Development Procedure

To ensure transparency and methodological clarity, the framework development process was structured into three sequential stages, as summarized in

Table 1. Framework development process in three stages.

Stage	Description	Key Activities
Stage 1: Concept Derivation	Review of existing literature and policy documents	Extraction of key sustainability concepts and assessment indicators (e.g., European Commission [11] and Ellen MacArthur Foundation [33])
Stage 2: Criterion Formulation	Structuring of assessment items	Definition of four core criteria—Renewability, Process Sustainability, EoL Options, and Material Source
Stage 3: Framework Structuring	Design of qualitative rating system	Establishment of assessment rules for the sustainability of textile materials based on a three-tier qualitative scale (Favorable/Conditional/Unfavorable)

. These stages reflect a stepwise progression from conceptual grounding to operationalization, enabling the systematic translation of theoretical insights into a structured and applicable analytical framework.

The framework builds upon the circular design perspective of textile value chains proposed by Ribul et al. [29], while extending and restructuring this perspective to align with the specific analytical objectives of the present study rather than adopting it directly.

Each assessment criterion for the sustainability of textile materials was defined based on explicit conceptual boundaries derived from prior literature on life-cycle-based assessment and sustainability indicator frameworks [16,30], with corresponding operational definitions systematically established to guide consistent application across materials and ensure repeatability of the assessment process.

For each criterion, qualitative thresholds were identified to distinguish between Favorable, Conditional, and Unfavorable ratings, following commonly adopted approaches in qualitative sustainability assessment and indicator-based evaluation frameworks [16,24]. Material evaluation was conducted based on predefined and consistently applied decision rules established within this study.

Materials were classified as Favorable when the specified condition was consistently achieved across relevant contexts, Conditional when the sustainability performance was contingent upon specific conditions or controlled environments, and Unfavorable when the required performance was not achieved or not supported by available evidence.

This rule-based classification approach aligns with prior studies emphasizing the importance of structured decision rules in ensuring consistency and interpretability in sustainability assessments [24,29], thereby enhancing cross-material comparability and supporting the reproducibility of the analytical process.

Based on the literature synthesis, these analytical dimensions were formalized as assessment criteria for the sustainability of textile materials. While each criterion is applied independently, all are embedded within a common interpretative framework to ensure systematic comparability across different material types.

2.4. Assessment Procedure

The 65 selected textile materials were analyzed using a three-tier qualitative rating scale—Favorable, Conditional, and Unfavorable—across the four assessment criteria.

A qualitative rating approach was adopted because materials differ substantially in technological maturity and data availability, as highlighted in prior studies addressing heterogeneity in sustainability assessment and data limitations [16,24]. Under such conditions, context-sensitive and structurally informed evaluation was considered more appropriate than purely quantitative comparison.

Explicit decision rules and operational definitions were established for each rating category and applied consistently across all materials to reduce subjectivity and ensure repeatability of the assessment process, following structured approaches in material-driven and sustainability evaluation frameworks [24,30].

To enhance the reliability and reproducibility of the assessment, the following procedures were implemented:

• Materials were grouped into five primary categories—plant-based, fungal/microbial-based, protein-based, recycled/upcycled, and bio-based synthetic or hybrid materials—based on commonly adopted classification approaches in textile sustainability research [17,30];
• Each material was assessed independently for renewability, process sustainability, EoL options, and material source; and
• Qualitative content analysis was conducted based on multiple data sources, including LCA studies, industrial reports, corporate disclosures, patents, and technical datasheets, drawing on established life-cycle-based assessment frameworks [14,30], thereby enabling consistent and reproducible interpretation under defined analytical criteria.

When inconsistencies across data sources were identified, the credibility and verification level of each source were assessed, consistent with life-cycle-based evaluation practices emphasizing data reliability and comparability [5,23]. Materials lacking sufficient third-party verification were not assigned to the three-tier rating categories but were instead flagged as “Assessment limited” to explicitly account for data uncertainty.

All evaluation decisions were documented with explicit references to supporting data sources and justification criteria in the Results section, ensuring transparency and reproducibility of the analytical process.

All materials were systematically assessed according to the four criteria defined, enabling consistent comparison across material types and supporting the identification of pathway-dependent variations in sustainability outcomes.

3. Results

3.1. Origin-Centered Classification of Textile Materials and Trend Analysis

This study systematically analyzed a dataset of 65 sustainable textile materials identified and described in Section 2 to examine how contemporary sustainability discourse in textiles is structured across material types using an origin-centered classification scheme commonly adopted in textile sustainability research [24,27]. The resulting classification of materials by biological and industrial origin is summarized in

Table 2. Systematic classification of textile materials by origin (n: 65).

Category	Sub-Category	Materials
Plant-Based	Agricultural & Natural	agave, bamboo linen, banana fiber (abacá), coconut coir, jute, kapok, lotus fiber, organic cotton, organic hemp, organic linen, palm leather, soy fabric, barley, and bagasse
	Agricultural Residue-Derived	corn husk, grain, Piñatex, rice straw, and wheat straw
	Food Waste-Derived	AppleSkin™, GrapeSkin, mango leather, orange fiber, tomato peel, and Vegea
	Marine- & Algae-Based	Kelsun™
Fungal- & Microbial-Based	Bacterial Cellulose-Based	kombucha leather (SCOBY), Modern Synthesis (biofabricated bacterial cellulose composite)
	Mycelium-Derived	ecovative mushroom materials, Mogu, MycoTEX® (NEFFA), Mylo™ (Bolt Threads), and Reishi™
Protein-Based	Natural Protein Fibers	ahimsa silk (peace silk), organic leather, organic silk, and organic wool
	Bioengineered Protein Fibers	Microsilk, Qmonos (bioengineered spider silk fiber), spider silk, and Werewool’s material
Recycled & Upcycled	Recycled Synthetic Fibers	Ocean Born Lifestyle (marine plastic-derived polyester), ECONYL® (recycled nylon), and rPET (recycled polyester)
	Reclaimed Natural Fibers	deadstock fabric, reclaimed cashmere, reclaimed cotton, and reclaimed wool
	Hybrid Recycled Materials	Algoblend® and recycled plastic
Bio-based regenerated and polymer-based materials	Regenerated Cellulosic Fibers	bamboo lyocell, Ecovero, modal, Tencel™, and SeaCell™
	Bio-based Synthetic Polymers (bioplastics)	algae-based foam (bio-based polymer composite), BioPTMG (bio-based polytetramethylene glycol), polybutylene succinate (PBS; Kintra Labs), poly (alkylene furanoate) (PAF), and polylactic acid (PLA)
	Bio-based Polymer Composites/Hybrids	ALT TEX™ bioplastic fiber, corn- & castor-based polyurethanes (PU), BioVERA (Modern Meadow), MIRUM® (Natural Fiber Welding), and Susterra® propanediol

Note: Regenerated cellulosic fibers include viscose, modal, and lyocell, which differ in processing mechanisms.

.

Detailed information on material structure (e.g., woven, knitted, nonwoven, composite) and intended application is provided in Appendix A (Table A1) as supplementary information. While structural classification (e.g., woven, knitted, nonwoven, composite) provides important contextual information, it is not treated as a primary analytical axis in this study, consistent with prior studies that highlight the limitations of single-axis material classification in capturing the multidimensional nature of sustainability [23,26]. Instead, this study adopts an origin-based classification approach combined with pathway-dependent interpretation to better reflect the complexity of sustainability outcomes in textile materials.

Table 2 classifies materials primarily according to material origin as the principal organizing criterion, while production pathways and processing characteristics are used only as secondary descriptors to support interpretation within each category. Composite or hybrid materials were classified based on their primary structural or polymer matrix, rather than on secondary additives or functional components. Accordingly, algae-derived polymers were retained in the algae-based category, whereas materials in which algae serves primarily as a secondary additive were classified under composite or hybrid materials.

Among the 65 materials analyzed, 40.0% were classified as plant-based materials, followed by bio-based regenerated and polymer-based materials (23.1%), recycled and upcycled materials (13.8%), protein-based materials (12.3%), and fungal and microbial-based materials (10.8%). This distribution provides a descriptive baseline for comparing how sustainability-related characteristics are represented across material categories.

These origin-based categories were used as an initial analytical step to examine prevailing research and industry discourse on the sustainability of textile materials, which remains strongly influenced by circular economy narratives and material-origin framing in existing literature [18,30]. It should be noted that these origin-centered categories reflect dominant industrial and research conventions rather than strict biological classifications, and are therefore employed as an analytical lens to interpret current sustainability discourse in the textile sector.

Table 2 further illustrates the internal structure of these categories, highlighting substantial variation within each group. In particular, plant-based materials are subdivided into four sub-groups (agricultural/natural, agricultural residue-derived, food waste-derived, and marine/algae-based), comprising between 3 and 14 materials per sub-group.

This origin-centered classification reflects the dominant logic underlying existing sustainability discussions in the textile sector and was adopted in this study as a starting point for examining trend distributions. As shown in Figure 1, sustainability discourse in textiles remains strongly anchored in materials of natural origin while simultaneously indicating the expansion of technology-driven materials integrating process engineering, chemistry, and circular design principles.

Notably, the plant-based category encompasses not only conventional natural fibers but also a wide range of materials derived from agricultural by-products and food waste. Across the 28 plant-based materials, at least four distinct feedstock pathways and multiple processing configurations are represented, indicating a high degree of internal heterogeneity in both material composition and production methods. As a result, this category forms a highly heterogeneous assemblage in which technological maturity levels and sustainability mechanisms vary substantially as consistently reported in prior studies addressing fiber diversity and life-cycle variability [18,24].

This internal variability highlights the limitations of origin-centered classification and underscores the need for a multi-dimensional interpretive framework capable of capturing pathway-dependent sustainability conditions across different material systems.

Materials such as AppleSkin^™, Piñatex, and VEGEA are frequently cited as emblematic examples of circular economy principles through waste valorization; however, the case analyses presented in Section 3.2 illustrate that their sustainability performance cannot be assumed to be inherently favorable and instead varies depending on processing pathways and binder chemistry. In particular, many of these materials rely on composite structures incorporating polymer-based coatings or binders, which can significantly influence recyclability and biodegradability outcomes, as reported in studies on composite material constraints and recycling limitations [26,27].

These findings further indicate that material structure and intended application act as key contextual variables influencing sustainability outcomes, particularly in relation to recyclability, material separation processes, and compatibility with end-of-life pathways [5,23,30].

Fungal and microbial-based materials represent a relatively small proportion of the dataset (n = 7, 10.8%) but emerge as a category with the potential to fundamentally reconfigure production processes and reduce chemical intensity through biofabrication approaches [34]. In contrast, protein-based materials (n = 8, 12.3%) encompass both traditional animal-derived fibers and bioengineered fibers within a single category. These two material types differ substantially in their sustainability implications: conventional animal-based fibers are primarily associated with ethical concerns and resource-intensive production, whereas bioengineered fibers introduce distinct challenges related to process intensity, technological scalability, and industrial feasibility [1,5].

Recycled and upcycled materials (n = 9, 13.8%) function as a key mechanism in circular economy transitions but continue to exhibit structural limitations, particularly in terms of material performance retention and high-value recycling pathways. These limitations are associated with polymer degradation during repeated processing, contamination from blended materials and additives, and technical challenges in separation and purification, as widely documented in recycling literature [24,25].

To assess whether these constraints are consistently reported across existing studies, a targeted literature screening was conducted focusing on structural limitations related to degradation, contamination, and separation difficulty. A subset of studies (n = 10), summarized in

Table 3. Verified structural constraints explicitly reported in selected studies (n = 10).

Ref	Material/System	Polymer Degradation	Contamination/Additives	Separation Difficulty	Evidence Basis
[18] Ribul et al., 2021	Textile recycling systems	✔	✔	✔	Closed-loop recycling limitations driven by material complexity and system constraints
[35] Hopewell et al., 2009	Plastics recycling	–	✔	✔	Sorting difficulty and contamination explicitly discussed at the system level
[36] Ragaert et al., 2017	Plastic recycling	✔	✔	✔	Mechanical recycling leading to polymer degradation; mixed waste contamination and sorting limitations
[37] Singh et al., 2017	Plastic waste recycling	✔	✔	✔	Combined effects of degradation, mixed waste contamination, and recycling inefficiency
[38] Jehanno et al., 2019	PET depolymerisation	✔	✔	✔	Impurities and depolymerisation limitations affecting recycling efficiency
[39] Tournier et al., 2020	PET enzymatic recycling	✔	✔	✔	Depolymerisation dependent on high-purity feedstock; contamination affects process efficiency
[40] Pringle et al., 2016	Leather recycling	–	✔	✔	Composite structure (tanned leather) and separation barriers in recycling processes
[41] Tonsi et al., 2025	Polyamide recycling	–	✔	✔	Selective dissolution constrained by impurities and separation challenges
[42] Maga et al., 2019	PLA recycling	✔	✔	✔	Recycling limitations including degradation, sorting constraints, and contamination
[43] Haslinger et al., 2019	Recycled cotton (blended textiles)	✔	✔	✔	Fiber degradation and challenges in separating blended materials (e.g., cotton/polyester)

Note: ✔ indicates that the structural constraint is explicitly discussed or evidenced in the referenced study; – indicates that it is not explicitly reported.

, indicates that these constraints represent recurring patterns across diverse material systems rather than isolated observations, consistent with prior synthesis studies on recycling system constraints [7,24]. Accordingly, these patterns should be interpreted as analytical evidence supporting the proposed framework perspective rather than as direct empirical validation of sustainability performance.

Bio-based regenerated and polymer-based materials (n = 15, 23.1%) represent a technological transition aimed at balancing performance requirements with sustainability objectives. However, their assessment is constrained by limited transparency and comparability, as evaluations often rely on manufacturer-provided data [44,45,46]. Within the present dataset, more than half of the materials in this category are characterized primarily on the basis of such disclosures rather than independently verified life-cycle assessment data.

Overall, the origin-based classification and distribution analysis demonstrate that the sustainability characteristics of textile materials cannot be sufficiently explained by biological origin alone [23,30]. Instead, multiple processing pathways, composite structures, and end-of-life scenarios coexist within each category, resulting in divergent sustainability outcomes depending on material design, processing technologies, and system-level conditions.

3.2. Comparative Case Study and Limitations

Material sustainability, as discussed in relation to plant-based materials in Section 3.1, cannot be adequately explained by biological origin alone [11,18,30]. Even when materials are derived from the same feedstock, their environmental performance may vary substantially depending on processing pathways, binder composition, and compatibility with EoL conditions [5,30].

To illustrate these limitations as an analytical application rather than as empirical validation, this section examines grape-based composite materials—VEGEA and the GrapeSkin^® family—both of which utilize grape pomace, a by-product of the wine industry, as a primary raw material (

Table 4. Comparative Specifications and Sustainability Implications of Grape-Pomace-Based Composite Materials (GrapeSkin^®/VEGEA).

Category	Supplier/Brand	Main Composition	Backing Fabric	Binder Type	Technical Features
VEGEA [47]	Vegea Company (Milan, Italy)	Grape pomace (skins, seeds, stems) + vegetal oils + bio-based polymers	Cotton or polyester	Water-based PU	Reduced toxicity vs. leather; PU limits biodegradability
GrapeSkin® (MoEa specification) [48]	MoEa (Paris, France)	55% grape-derived content + 45% water-based PU	100% rPET	Water-based PU	High renewable content; limited recyclability
GrapeSkin® (general retail specification) [49]	Retail product (Immaculate Vegan)	26% grape pomace + 54% recycled polyester + 20% water-based PU	Backing integrated in coating layer (rPET-based microfiber structure)	Water-based PU	Variable structure; uncertain EoL performance

Note: Specifications are based on supplier and retail data. Due to lack of verified LCA data, materials are marked as “Assessment limited”. The retail product specification is based on publicly disclosed product-level information from Immaculate Vegan and may differ from supplier-level material specifications. Specifications vary by supplier disclosure and product application.

).

Given the current lack of harmonized datasets and comparable assessment standards for textile material sustainability, this case study does not aim to provide statistical validation, but rather to demonstrate how the proposed framework operates under real-world data constraints. Accordingly, the analyzed materials are classified as “Assessment limited” to reflect data uncertainty, consistent with limitations reported in life-cycle-based and recycling studies regarding data availability and comparability [5,18,24].

VEGEA utilizes grape skins, seeds, and stems generated during wine production and describes its material as a bio-based composite composed of plant-derived, renewable, and bio-based polymer components [47]. According to publicly available technical information, the coating layer of VEGEA consists of a combination of vegetal oils and water-based polyurethane (PU), while the backing fabric is reported to be either cotton or polyester [49,50]. Although water-based PU may offer advantages in terms of reduced VOC emissions compared to solvent-based processes, PU is generally considered resistant to biodegradation under typical environmental conditions, which may limit full compostability [51,52,53].

The GrapeSkin^® family likewise shares the same grape pomace feedstock; however, publicly available information indicates that its composition and structure vary depending on the supplier or product specification. For example, the grape-derived content in GrapeSkin^® varies from approximately 26% to 55%, representing more than a twofold difference depending on product specification, while the proportion of synthetic binders such as PU correspondingly increases to meet functional performance requirements.

MoEa, for instance, specifies a coating composed of grape-derived components and water-based PU with an rPET backing layer [48], whereas other retail and secondary sources report different compositional ratios [54].

Notably, the retail-level specification presented in Table 4 corresponds to a footwear application, which requires higher abrasion resistance, structural rigidity, and shape stability than bags or small accessories. These application-specific performance requirements are likely to influence material composition and processing configurations, leading to increased reliance on synthetic binders and reinforcement layers [5,18,24].

These observations indicate that even when the same raw material is used, coating composition, backing textiles, and processing conditions can differ substantially, resulting in divergent sustainability conditions within the same origin category.

In particular, for coated composite materials, design-related factors—including binder matrix properties, backing textile composition, and compatibility with post-use treatment pathways—play a decisive role in shaping environmental performance, as reported in studies on composite materials and recycling constraints [24,25]. Across the analyzed dataset, approximately 39.4% (n = 26) of materials were classified as “Assessment limited” due to insufficient availability of verified LCA or third-party environmental performance data. This observation further reinforces the limitations of origin-based classification and highlights the analytical relevance of the proposed multi-dimensional framework.

Composite and layered configurations may limit recyclability due to challenges in material separation, while application-specific performance requirements can necessitate additional binders or reinforcement layers, thereby constraining end-of-life options [24,25].

Building on these material-specific observations, the analysis suggests that sustainability performance of textile materials cannot be attributed to a single material attribute alone but is shaped by interactions among material composition, processing conditions, and EoL compatibility, as emphasized in life-cycle-based analytical frameworks [23,31]. For instance, bio-based or biogenic materials may exhibit favorable characteristics in terms of resource origin; however, their end-of-life performance may remain conditional depending on biodegradation requirements or the presence of composite structures. Similarly, materials with recyclable potential may be constrained by process-related factors such as energy demand, chemical use, or solvent recovery efficiency.

Taken together, these findings indicate that sustainability outcomes are not intrinsic properties of materials themselves but are emergent properties arising from the interaction of multiple system-level factors.

3.3. Development of a Multi-Dimensional Sustainability Assessment Framework

To address the limitations of existing classification approaches, this study develops a multi-dimensional interpretive framework for analyzing the sustainability conditions of textile materials [16,17]. The framework builds on the analytical structure derived from the literature review and framework development procedures described in Section 2 and moves beyond single-indicator approaches—such as LCA-based assessments or biodegradability alone—by enabling an integrated interpretation of environmental and technological dimensions [5,15,26,27]. Rather than functioning as a standalone evaluation model, the framework is designed to complement LCA-based approaches by providing a structural interpretive lens applicable to emerging and data-scarce materials.

This perspective highlights the limitations of conventional single-indicator approaches and allows for a more explicit distinction in relation to LCA-based methods. Unlike conventional LCA approaches that rely primarily on quantitative indicators, the proposed framework offers a pathway-oriented interpretation of sustainability. In particular, it captures structural dependencies among material composition, processing routes, and end-of-life scenarios, which are often not explicitly addressed in indicator-driven assessments. This distinction underscores the analytical contribution of the framework as a complementary tool rather than a replacement for existing evaluation methods.

Based on the analytical framework development process described above, four core assessment criteria were identified: Renewability, Process Sustainability, EoL Options, and Material Source. These criteria were informed by prior literature on life-cycle-based assessment and sustainability indicator frameworks [16,30]. Specifically, the selection was guided by three considerations: (1) coverage of the full life cycle (from resource origin to end-of-life), (2) representation of both material and process-level factors, and (3) relevance to pathway-dependent sustainability outcomes identified in prior studies [16,30].

While additional indicators (e.g., durability, recyclability, or process-related environmental and chemical impacts such as resource use, emissions, and hazardous substance management) identified in policy frameworks and certification systems [11,12,13,19,20] could be considered, these are either subsumed within the selected criteria or represent outcome-specific extensions. Accordingly, the four selected criteria are defined as a parsimonious yet structurally comprehensive set of dimensions sufficient to capture pathway-dependent sustainability outcomes.

Criteria related to economic and social dimensions were not included in this framework, as the focus of this study is on identifying structural variables governing material–process–EoL interactions rather than providing a comprehensive, indicator-based sustainability assessment. Within this analytical scope, the selected criteria are considered appropriate for capturing the key structural factors influencing pathway-dependent sustainability outcomes.

These criteria capture interrelated dimensions shaping sustainability trajectories across the life cycle, consistent with system-oriented analytical perspectives [18,30]. From this perspective, sustainability is interpreted as a configuration-dependent outcome arising from interactions among material composition, processing conditions, and end-of-life pathways.

To demonstrate the operational application of the proposed framework, an illustrative mapping exercise was conducted across a dataset of 65 textile materials. This mapping is presented as an analytical demonstration of framework applicability rather than as a comprehensive evaluation of all materials.

Material assessment was conducted using a three-tier qualitative rating scale—Favorable, Conditional, and Unfavorable—to enable comparison across materials with different levels of technological maturity and data availability. The qualitative scale was applied using predefined decision rules to ensure consistency and is intended for structured interpretation rather than precise quantitative evaluation, consistent with general practices in qualitative sustainability assessment [16]. Where assessments relied primarily on manufacturer-provided information or lacked third-party verification, materials were not assigned to the three-tier rating categories but were instead flagged as “Assessment limited” to explicitly reflect data uncertainty rather than to provide definitive performance assessment.

Table 5. Four core criteria of the sustainability evaluation framework for textile materials.

Evaluation Criterion	Main Assessment Focus	Representative Indicators	Qualitative Rating/Classification	Reference Basis
Renewability	Whether the material is biogenic or waste-derived	Biogenic origin of feedstock, competition with food resources	Favorable/Conditional/Unfavorable	[11] European Commission (2019); [14] ISO (2006); [51] Reddy et al. (2013); [55] Oliveira et al. (2020); [56] Shen et al. (2009); [57] Vink et al. (2003)
Process Sustainability	Energy, chemical, and emission intensity during production and recycling	Energy demand, chemical use, solvent recovery rate	Favorable/Conditional/Unfavorable	[3] Gonzalez et al. (2023); [5] Moazzem et al. (2021); [14] ISO (2006); [23] Van der Velden et al. (2014); [24] Baloyi et al. (2024); [27] Harmsen et al. (2021); [30] Muthu (2015)
EoL Options	Potential for biodegradation, recycling, or energy recovery	Biodegradation conditions, recycling infrastructure, disassembly feasibility	Favorable/Conditional/Unfavorable	[11] European Commission (2019); [22] UNEP (2023); [33] Ellen MacArthur Foundation (2019)
Material Source	Type and circularity of the origin	Natural/Bio-based/Recycled/Mixed	Categorical classification (contextual)	[27] Harmsen et al. (2021); [58] Wang & Salmon (2022); [59] Niinimäki & Karell (2020)

Note: Ratings are based on a qualitative three-tier scale (Favorable, Conditional, Unfavorable). Material source is used as contextual information rather than a performance rating criterion. Materials with insufficient third-party data or solely manufacturer-reported claims are not assigned to the three-tier rating categories but are instead flagged as “Assessment limited”. ISO (2006) [14] provides the overarching LCA principles applied across multiple assessment criteria.

summarizes the focus, representative indicators, and supporting references for each criterion. This table should be positioned immediately after its first mention to support readability and logical flow. The framework complements conventional LCA by incorporating qualitative parameters applicable to emerging or data-scarce materials, thereby enhancing its interpretive applicability under conditions of limited data availability, rather than serving as a performance validation tool.

3.3.1. Renewability

In this study, renewability is not treated as a binary attribute based solely on whether a material is bio-based. Instead, it is defined as a sourcing-oriented criterion that considers both feedstock origin (biological or waste-derived) and sourcing conditions, including implications for land use, food systems, and ecosystems [57,60,61]. This definition reflects the premise that materials labeled as “bio-based” may exhibit substantially different sustainability outcomes depending on feedstock sourcing pathways and associated environmental conditions.

From this perspective, materials derived from plants, algae, microorganisms, and bioengineered proteins are interpreted as exhibiting relatively favorable renewability within the proposed analytical framework, depending on sourcing pathways and production conditions. In particular, microbial fermentation and biofabrication routes may, under certain conditions, reduce direct dependence on agricultural land, thereby potentially alleviating pressures related to land-use change and food–feed competition [24,62].

By contrast, bio-based polymers such as polylactic acid (PLA), polybutylene succinate (PBS), and poly alkylene furanoate (PAF) are not automatically interpreted as highly renewable, as their renewability depends on cultivation practices, land-use change, and competition with food or feed crops. Accordingly, within the proposed framework, these materials are interpreted as conditionally renewable rather than inherently favorable [57,60,61].

Recycled synthetic fibers such as rPET and ECONYL^®, while derived from non-renewable feedstocks, were included because they substitute virgin resource inputs and contribute to closing material loops through waste recovery [24,63]. These cases demonstrate that renewability and circular contribution represent analytically distinct dimensions. A material may be derived from renewable resources without contributing to circular material flows, whereas non-renewable materials may still play a significant role in circularity through recycling and resource recovery pathways [23,64].

Based on this interpretation, renewability is positioned along a three-level qualitative scale, where biofabricated and microorganism-derived materials are generally categorized as Favorable, bio-based polymers such as PLA, PBS, and PAF as Conditional, and fossil-derived materials as Unfavorable, consistent with general practices in sustainability indicator frameworks [16]. These classifications are presented as illustrative applications of the proposed qualitative rating system and should not be interpreted as empirical validation of the sustainability performance of textile materials.

3.3.2. Process Sustainability

In this study, process sustainability is interpreted in terms of the intensity of energy use, chemical inputs, emissions control, and recovery systems required during material production and recycling, including solvent recovery and wastewater treatment [31,45]. This interpretation emphasizes that environmental burdens are often determined more by processing pathways and control systems than by feedstock origin alone. Accordingly, process sustainability is evaluated qualitatively based on process severity, the use of hazardous substances, and the efficiency of recovery and purification systems..

Mycelium-based and bacterial cellulose (BC) materials are typically produced under relatively low-temperature, aqueous conditions with limited reliance on high-risk solvents, and are therefore interpreted as comparatively favorable in terms of process sustainability [52,65,66,67]. However, process burdens may vary depending on culture media, cultivation efficiency, and post-processing steps such as drying or coating [67].

For cellulose-based fibers, process sustainability is primarily determined by the solvent system and its recovery efficiency. Conventional viscose processes using carbon disulfide (CS₂) are generally associated with higher chemical hazards and emission management burdens, whereas lyocell fibers produced via direct dissolution of cellulose using N-methylmorpholine N-oxide (NMMO), and modal fibers produced through modified viscose processes, exhibit comparatively improved performance due to closed-loop solvent recovery systems [45,46,48].

Bio-based polymers such as PLA and PBS are interpreted as exhibiting moderate process sustainability within the analytical framework, as polymerization and purification stages may involve high energy demand and the use of catalysts or solvents [51]. PU-based hybrid materials may exhibit substantial variability depending on process design parameters such as catalyst selection, solvent use, and production configuration, as demonstrated in comparative assessments of PU production pathways [53].

These observations collectively suggest that process design and recovery systems function as primary determinants of environmental performance in textile materials, rather than attributes that can be inferred solely from material origin [30,45].

3.3.3. End-of-Life Options

In this study, EoL options were interpreted based on whether biodegradation or recycling pathways can realistically operate within existing waste-management systems, rather than on declarative claims of theoretical biodegradability or recyclability [23,31]. Accordingly, EoL performance is interpreted as a system-dependent outcome that requires appropriate processing conditions, supporting infrastructure, and compatibility with product design.

Within the set of materials analyzed in this study, natural fiber-based and microorganism-based materials, such as mycelium and bacterial cellulose, were interpreted as relatively favorable under specific controlled conditions where biodegradation has been demonstrated. However, composite materials incorporating coatings, adhesives, or layered structures exhibited divergent EoL outcomes depending on binder chemistry and the feasibility of delamination [24,25,52]. These findings indicate that EoL pathways are largely determined upstream during material formulation and product design.

Bio-based polymers such as polylactic acid (PLA) and polybutylene succinate (PBS) can degrade under industrial composting conditions, but were interpreted as conditionally favorable within the analytical framework because effective EoL performance depends on the availability of appropriate collection systems and treatment infrastructure [31,57,60]. As such, EoL outcomes vary depending on regional infrastructure maturity, source separation practices, and contamination levels.

For recycled synthetic fibers such as rPET and PA6, recyclability depends on contamination, mono-material design, and alignment between collection, sorting, and recycling systems [23,35,37,64]. These cases demonstrate that EoL performance is not an intrinsic material property but a systemic outcome shaped by interactions between product design and waste-management infrastructure.

These findings indicate that EoL performance emerges from system-level interactions among material composition, product design, and waste-management infrastructure.

3.3.4. Material Source

In this study, material sources were interpreted across three broad categories—natural, bio-based, and recycled—while hybrid materials (e.g., Algoblend^®) were labeled as mixed-source [27,58,59]. This typology is used to provide contextual information for interpreting processing pathways and EoL options, rather than to directly determine sustainability performance.

In sustainability research, material source is often treated as a proxy for environmental performance, implying comparability among materials with the same origin. However, this assumption overlooks the critical role of downstream process design and composite structure in shaping sustainability outcomes. The contrast between bamboo lyocell (bio-based) and bamboo linen (natural) provides an example of this distinction: despite a shared feedstock, their environmental profiles and circularity potential differ due to solvent systems, process control, and chemical recovery [46,68,69,70]. While origin-based labels may support consumer communication, they provide limited insight into actual environmental performance and may obscure process-related trade-offs.

The limitations of source-based classification are more pronounced for hybrid and composite materials. Combining bio-derived components with synthetic binders or reinforcement layers decouples feedstock origin from EoL performance. In such cases, binder chemistry and layered structures become primary determinants of the feasibility of separation, recycling, or biodegradation.

Accordingly, the framework treats material source as contextual information rather than a performance score. Sustainability performance is therefore interpreted as a pathway-dependent outcome shaped by the combined effects of material origin, process design, binder composition, and EoL compatibility [24,47,48]. This perspective prevents over-reliance on origin-based labels and strengthens the interpretive robustness of the framework.

Taken together, these findings reinforce that sustainability performance is not determined by any single attribute but emerges from interactions among multiple analytical dimensions [18,26].

4. Conclusions

This study developed a qualitative, multidimensional classification framework to interpret the sustainability of textile materials by integrating material composition, processing pathways, and end-of-life compatibility within a unified analytical structure. The proposed framework demonstrates that sustainability performance emerges as a system-level outcome arising from structural interactions among materials, processes, and end-of-life pathways, based on an example mapping of 65 textile materials, with detailed interpretation applied to selected cases.

Moving beyond conventional approaches based on material origin or isolated environmental indicators, this study reconceptualizes sustainability as a pathway-dependent and configuration-driven phenomenon. The absence of fully standardized and empirically comparable datasets across textile materials highlights a critical gap in current sustainability research. Within this context, the proposed framework provides a structured analytical basis for interpreting fragmented and heterogeneous data environments, thereby supporting more consistent and transparent evaluation efforts.

The origin-centered classification of the 65 materials into five categories—plant-based, fungal- and microbial-based, protein-based, recycled and upcycled, and bio-based regenerated and polymer-based materials—reveals substantial heterogeneity within each group. This distribution reflects both the persistence of origin-based classification paradigms and the increasing influence of materials shaped by process engineering and composite design.

The qualitative content analysis conducted in this study indicates that sustainability performance cannot be explained by material origin alone but is instead determined by the interaction of processing pathways, structural configurations, and EoL compatibility. Even among materials derived from similar feedstocks, substantial variation arises depending on solvent systems, manufacturing processes, binder composition, composite structures, and compatibility with existing waste management systems. These findings highlight the structural limitations of binary classification frameworks (e.g., “natural versus synthetic” or “bio-based versus fossil-based”) and underscore the need for pathway-oriented analytical approaches.

A closer examination of grape-waste-derived materials (e.g., VEGEA) provides analytical evidence that, despite their frequent association with circular economy principles, their sustainability performance may vary depending on coating systems and binder chemistry. Based on existing studies, such materials can exhibit divergent outcomes in terms of recyclability and biodegradability, indicating that sustainability performance is not inherent to feedstock origin but emerges from downstream processing conditions and material integration.

Across the four analytical dimensions, renewability was found to depend on feedstock sourcing pathways rather than a simple bio-based classification. Process sustainability was primarily governed by manufacturing design and solvent systems rather than material origin. EoL performance was strongly influenced by structural factors such as multilayer configurations, binder chemistry, and separability, suggesting that EoL outcomes are largely predetermined during material and product design. In addition, material source functioned as a contextual variable with limited explanatory power when considered in isolation. Collectively, these findings indicate that sustainability should be understood as a system-level outcome arising from interacting structural variables rather than as an intrinsic property of materials.

Rather than serving as a tool for ranking materials based on quantitative indicators, the framework establishes a consistent analytical basis for interpreting pathway-dependent sustainability performance under varying structural conditions.

From a practical perspective, the proposed framework can be applied as a structured decision-support tool that helps stakeholders understand how specific design and sourcing choices are translated into sustainability outcomes. By shifting the analytical focus from material substitution to pathway-oriented design, the framework enables a more systematic evaluation of how material composition, processing pathways, and EoL options interact under real-world conditions.

At the material sourcing stage, the framework encourages designers and merchandisers to move beyond simplified origin-based classifications (e.g., “bio-based” or “recycled”) by explicitly considering process-related variables such as energy intensity, solvent systems, and binder composition, together with EoL compatibility. This approach supports more context-sensitive material selection by integrating both upstream and downstream implications into decision-making processes.

During material and composite design, the framework provides a mechanism for identifying how structural variables—such as layered configurations, binder chemistry, and separability—directly influence the feasibility of recycling or biodegradation pathways. By making these dependencies explicit at early design stages, the framework helps prevent unintended outcomes, such as materials that are renewable in origin but incompatible with existing recovery or disposal systems.

In the context of sustainability communication, the framework offers a structured basis for assessing the validity and scope of environmental claims. In particular, categories such as “Assessment limited” (used as a flag to indicate data uncertainty rather than a rating category) enable stakeholders to explicitly acknowledge data uncertainty and distinguish between verified and non-verified sustainability information, thereby supporting more transparent and credible communication.

Furthermore, the framework can support alignment with emerging policy and regulatory requirements. By organizing material-level information in terms of process conditions and end-of-life pathways, it provides a structure that can be integrated into lifecycle-based policy instruments such as digital product passports and extended producer responsibility schemes, thereby facilitating more proactive compliance.

For example, in outerwear applications that require both durability and EoL compatibility, a bio-based polymer with high renewable content but energy-intensive processing does not necessarily lead to superior sustainability performance compared to a recyclable synthetic fiber designed for mono-material recovery.

The framework shifts the focus of sustainability practice from material substitution toward pathway-oriented design by explicitly identifying the structural interactions that govern sustainability performance across the product life cycle.

This study has several limitations. It does not incorporate quantitative LCA indicators, interprets EoL performance under generalized system conditions, and focuses on material-level analysis without explicitly addressing use-phase impacts. In addition, the study does not aim to provide empirical validation or predictive assessment. These limitations reflect the exploratory and framework-oriented nature of the study rather than methodological shortcomings.

Future research should integrate quantitative LCA data, region-specific EoL infrastructure scenarios, and product-level performance variables to enhance the explanatory power and applicability of the framework. Building on this foundation, subsequent research will extend the framework through empirical and data-driven validation. In particular, subsequent research will focus on empirically evaluating the distribution and convergence of sustainability pathways across textile materials, thereby providing data-driven validation of the proposed analytical framework.

These contributions position the proposed framework as both a conceptual foundation and a practical analytical tool for advancing pathway-oriented sustainability research in the textile and apparel domain.