Mapping Polyester Waste Stream and Recyclability: A Material Flow Analysis of Indonesia’s Textile and Clothing Industry

Abstract

Indonesia, as a major global textile exporter, faces substantial sustainability challenges due to its linear production model, which generates massive volumes of post-industrial polyester waste (PIPW). However, reliable data and recycling pathways remain critically lacking. This study quantifies the volume, composition, and textile-to-textile (T2T) recyclability potential of PIPW across Indonesia’s national textile and clothing production chain, employing a mixed-methods approach that integrates material flow analysis (MFA), site visits, and stakeholder interviews. The results indicate that 572 kilotonnes of PIPW were generated in 2023, with garment manufacturing identified as the most waste-intensive. Nineteen waste types were identified; 61% comprise fibre blends, which significantly constrain closed-loop recycling. A novel five-tier waste typology was developed to classify waste streams based on material characteristics, technological availability, and economic feasibility. The circularity map reveals that Indonesia is trapped in pseudo-circularity. Scenario analysis suggests that up to 184 kilotonnes of PIPW could be feasibly redirected towards higher-value chemical recycling. The research recommends mandatory source segregation, fiscal incentives, investment in chemical recycling infrastructure, and the integration of circular design into national standards. The study provides the first national-level MFA of PIPW in Indonesia and establishes an empirical baseline to advance T2T recycling in emerging economies.

1. Introduction

Indonesia’s position as a major global textile exporter is undermined by a linear production model that generates massive volumes of post-industrial polyester waste (PIPW), for which reliable data and recycling pathways are critically lacking. Post-industrial textile waste is defined as material losses generated during textile manufacturing processes across fibre-to-garment production stages, including unused materials and production residues arising within manufacturing facilities [1,2]. The country’s exports exceeded USD 11 billion in 2024, accounting for approximately 1.3% of the global market, with the US and the EU as the primary markets [3]. Behind these contributions, the Ministry of National Development Planning reported that the total volume of post-industrial textile waste reached 300 kilotonnes in 2019 and is projected to rise to 500 kilotonnes by 2030 [4]. Unfortunately, only 12 percent of this waste is recycled, primarily through low-value downcycling, while the remainder is disposed of in landfills, causing significant ecological damage and substantial loss of material value [4,5]. However, these national estimates are reported in aggregate form and have not yet been systematically analysed by fibre type or waste category. Without granular data on the generation, composition, and recyclability of PIPW, it is challenging to construct targeted circular interventions or measure their effectiveness within national policy or industrial practice. Fibre-specific disaggregation of PIPW is essential for accurately identifying opportunities to enhance circularity [6]. This imperative is further strengthened by mounting global pressure to accelerate textile-to-textile (T2T) recycling and reduce reliance on the bottle-to-textile (B2T) system, which currently dominates recycling practices [7,8].

This study focuses on polyester due to its structural dominance and system-level relevance within both the global and Indonesian textile economy. Polyester currently accounts for more than half of global fibre production, making it the most material-intensive input in textile manufacturing systems [7,9,10]. This dominance is mirrored in Indonesia, where polyester similarly represents approximately 54% of national textile fibre production [3]. From a circularity and resource-efficiency perspective, polyester is particularly consequential because its widespread use across multiple product categories amplifies cumulative material demand, while its life-cycle impacts are substantially higher than those of natural fibres [11,12,13]. Consequently, inefficiencies in polyester-dominated production systems translate into disproportionate material losses at the system level. A fibre-specific focus on polyester, therefore, provides a strategic entry point for diagnosing structural inefficiencies, assessing the feasibility of recycling, and evaluating the realistic potential of T2T recycling within Indonesia’s T&C value chain.

The limited contribution of T2T recycling, particularly from polyester fibres, suggests greater complexity than other raw materials. This complexity stems from a series of significant structural and institutional challenges, including a lack of collaboration among industry actors [14], limited traceability of waste streams [15], insufficient sorting and recycling technologies [16], and the absence of adequate economic incentives to support investment in advanced and large-scale recycling technologies [17,18]. In addition, most recycling companies continue to rely on rudimentary mechanical methods, which are inadequate for processing fibre blends, particularly those containing polyester [19]. In contrast, chemical recycling is necessary to produce high-quality recycled textiles [20,21]; however, it remains under development and involves high investment costs [20,22].

Furthermore, national policy frameworks on textile circularity do not yet support closed-loop systems, and extended producer responsibility (EPR) has not been enforced [23]. At the industry level, poor awareness of systemic segregation, a lack of transparency in data on waste volume and type, and inconsistencies in reporting across production facilities further hinder efforts to map value chains and operationalise effective circular business models [24,25,26]. Consequently, the circular potential of PIPW remains significantly underutilised, even though its relatively clean and homogeneous nature generally renders it more technically and economically viable for reintegration than post-consumer textile waste in industrial recycling contexts [27,28].

Addressing these multi-level challenges requires a systemic approach underpinned by granular, fibre-specific data. The transition towards a sustainable circular textile economy necessitates not only advances in downstream recycling technologies but also upstream interventions grounded in a thorough understanding of material flows, waste-generation patterns, and fibre-specific recyclability. Material Flow Analysis (MFA) has been widely recognised as an effective method for tracing material inputs, outputs, and stock changes within industrial processes [13,29]. It offers critical insights into inefficiencies, leakages, and recovery potential, particularly valuable in fragmented production systems such as Indonesia’s textile sector. Despite its strengths, MFA remains underapplied in the context of PIPW, particularly in developing economies. The lack of fibre-specific, context-aware assessments continues to hinder the development of effective policy frameworks and industrial strategies to unlock the latent circularity potential of PIPW.

Importantly, within a circular economy framework, the recovery of industrial textile waste does not occur through a single recycling route but rather through a portfolio of alternative end-of-life (EoL) pathways that differ in value retention, technological requirements, and operational feasibility [30,31,32]. Prior studies report that textile waste can be channelled into distinct EoL pathways depending on material characteristics and system conditions. Remanufacturing is typically applied to highly homogeneous and uncontaminated waste streams [33], whereas mechanical recycling is still predominantly used for nonwoven applications and lower-value industrial products [1], although under certain conditions, it may also support T2T applications [9]. Chemical recycling is positioned as a higher-value recovery route for mixed-fibre waste fractions [19,34]. Repurposing is commonly practised by small and medium-sized enterprises (SMEs) in developing countries [27] where textile waste is transformed into products with diverse functions, such as handicrafts and home textiles. Incineration and landfill are generally considered last resort options for waste fractions that do not meet the technical criteria of other EoL pathways [19,35]. Understanding how PIPW is distributed across these alternative EoL pathways is therefore essential for assessing its practical circularity potential and for identifying opportunities to redirect waste streams from low-value disposal to higher-value recovery and valorisation. However, pathway-oriented analyses that systematically link fibre-specific waste characteristics with feasible recovery routes remain limited, particularly in emerging textile-producing economies.

Most existing studies on textile waste have focused on post-consumer streams in developed economies [13,36,37], leaving upstream industrial residues largely overlooked. In the case of PIPW, studies are scarce and typically narrow in focus, analysing single production stages or drawing on limited sample scopes that do not reflect the complexity of large-scale textile manufacturing [4,5,6,7,8]. Consequently, there is a persistent lack of robust data on the national-scale generation, composition, and recyclability of polyester waste, particularly in structurally diverse sectors such as Indonesia’s. This evidence gap constrains both policy innovation and industrial investment in closed-loop recycling systems. It also obscures the scale of the feedstock supply that could support chemical valorisation technologies, thereby limiting Indonesia’s ability to transition to higher-value circular pathways. To address this gap, the present study poses the following question: What is the volume, composition, and T2T recyclability potential of PIPW across Indonesia’s T&C value chain?

This study aims to map the T2T recycling potential of PIPW in Indonesia using a systematic, multi-method approach. At the core of the analysis is a national-scale MFA, through which material flows across the T&C production chain are quantified and waste generation at each production stage is estimated. The analysis is complemented by site visits, semi-structured interviews, and a focus group discussion (FGD) with key stakeholders, enabling an in-depth examination of process inefficiencies, waste characteristics, recyclability scoring, waste typology, and the allocation of PIPW across multiple EoL pathways (Scenario A). Building on this empirical foundation, the study further develops a valorisation scenario to explore the potential redirection of selected waste fractions from low-value recovery and disposal routes towards higher-value chemical recycling. This integrated approach provides a robust evidence base for assessing the availability of eligible feedstocks and for encouraging segregation and strategic investment in closed-loop recycling.

By integrating quantitative material flow modelling with qualitative stakeholder insights, this study develops a first national-scale, fibre-specific MFA of PIPW in Indonesia. It develops a novel five-tier typology of recyclability by systematically combining a comprehensive MFA with an expert-based assessment that links material characteristics, economic feasibility, and technological availability. These contributions offer a robust empirical basis for advancing fibre-specific circularity strategies and supporting Indonesia’s transition towards a more circular, inclusive, and resource-efficient polyester textile system. Moreover, the study provides evidence-based insights to support future planning and investment decisions. Finally, the analytical framework developed is transferable to other textile-producing economies facing similar structural and data-related challenges.

2. Results

This section presents the principal findings of the study: (1) polyester flow and waste generation; (2) waste typology; and (3) potential circularity map. The production chain is segmented into three categories: upstream, midstream, and downstream. In the final section, this study proposes implications and recommendations to improve closed-recycling practices in Indonesia. For consistency with the system-level MFA and Sankey visualisation, waste generation is discussed at the aggregated production-chain level. In contrast, waste ratios and material efficiency are reported at the sub-process level to capture intra-stage heterogeneity.

2.1. Polyester Flow and Waste Generation in Indonesia’s T&C Production Chain

The polyester flow and PIPW generation across Indonesia’s T&C manufacturing chain in 2023 are visualised in Figure 1. The system was supplied by a combination of domestic production and imported intermediates, with final outputs distributed to four primary destinations: the domestic T&C sector, domestic non-textile industries, domestic textile non-apparel sectors, and export markets. The analysis revealed that approximately 572 kilotonnes (kt) of PIPW were generated within the system.

The production chain commences in the upstream segment, encompassing polymerisation, fibre manufacturing, and yarn manufacturing. During polymerisation, a total of 1452 kt of purified terephthalic acid (PTA) and 497 kt of monoethylene glycol (MEG) are processed into three main outputs: 794 kt of polyester pellets, which are tracked as an outflow to non-textile sectors; 560 kt of polyester staple fibre (PSF); and 556 kt of polyester filament fibre (PFF). This stage also generates 39 kt of PIPW. PSF is subsequently channelled to the spinning stage, while PFF proceeds to the texturising stage. In the spinning stage, 479 kt of PSF and 850 kt of other staple fibres are blended into 1262 kt of spun yarn, of which 453 kt are diverted to non-apparel sectors and the remainder is supplied to domestic fabric manufacturing. Concurrently, the texturising stage converts 650 kt of filament fibres into 637 kt of textured yarn. Collectively, these yarn manufacturing processes generate 79 kt of PIPW, primarily comprising off-specification fibres and residual by-products.

In the midstream segment, yarns were processed into fabric by knitting and weaving. Approximately 1284 kt of yarn were transformed into 1220 kt of greige fabric, generating 64 kt of PIPW. Subsequent wet processing produced an additional 68 kt of waste. This stage also marked the primary entry point for imported textile materials (604 kt). The downstream sector, garment manufacturing, processed 1786 kt of finished fabric into 1464 kt of apparel, resulting in 322 kt of PIPW, equivalent to 56% of the total PIPW. This stage is therefore identified as the most waste-intensive segment of the value chain.

To verify internal consistency, the PIPW quantification was validated using a stage-level mass-balance check under the steady-state assumption. Based on the quantitative data sources and MFA assumptions described in Section 4.2.1, the inflow, outflow, and waste values reported in

Table 1. Stage-level mass balance and closure error of polyester flows in Indonesia’s T&C manufacturing chain (2023).

Production Chain	Total Inflow (kt)	Total Outflow (kt)	Waste (kt)	Closure Error (%)
Polymerisation & fibre manufacturing	1949	1910	39	0.0
Yarn manufacturing	1978	1898	80	0.0
Fabric manufacturing	1284	1220	64	0.0
Wet processing	1694	1626	68	0.0
Garment manufacturing	1786	1464	322	0.0
System total	- *	- *	572	- *

* System total inflow and outflow are not reported due to inter-stage aggregation.

were derived from process-based material flow calculations integrating national industrial statistics, international trade data, site visits, and stakeholder interviews.

Table 1 summarises total inflows, total outflows, and waste generation for each aggregated production stage. Under the steady-state assumption (net stock change = 0), waste generation represents the residual flow required to close the mass balance at each stage. The reported zero closure error does not indicate the absence of uncertainty; it reflects the accounting-based reconciliation of inflows, outflows, and waste at the aggregated production-stage level, as commonly applied in national-scale MFA studies. System-level total inflows and outflows are not reported because inter-stage aggregation and the avoidance of double-counting across sequential production stages preclude their reporting.

These patterns were corroborated by the waste ratio and material efficiency for each process, as presented in

Table 2. Waste ratios and material efficiency of Indonesia’s polyester T&C production.

Production Chain	Sub Process	Waste Mass (kt)	Waste Ratio (%)	Material Efficiency (%)
Polymerisation & fibre manufacturing	Polymerisation & fibre manufacturing	39	2	98
Yarn manufacturing	Yarn spinning	66	5	95
	Texturising	13	2	98
Fabric manufacturing	Weaving	45	7	93
	Knitting	19	3	97
Wet processing	Wet processing	68	4	96
Garment manufacturing	Garment manufacturing	322	18	82
Total		572

Source: Derived from aggregated MFA results integrating national industrial statistics and international trade data (see Section 4.2.1).

. Waste ratio is an indicator that represents the proportion of residue relative to resource consumption. In contrast, material efficiency is the percentage of raw materials successfully converted into products that meet the required standards. By normalising waste generation relative to material inputs, these indicators provide a resource-oriented perspective on circularity and allow a distinction between waste generation driven by production scale and that driven by structural inefficiencies in resource use. Garment manufacturing exhibited the highest waste ratio (18%) and the lowest material efficiency (82%). Conversely, upstream stages achieved markedly higher efficiency (95–98%), while midstream operations showed intermediate waste ratios (3–7%) and efficiency rates of 93–97%, revealing a transparent gradient in material retention performance along the production chain.

To complement the quantitative MFA, site visits were conducted in three representative firms across Indonesia’s polyester T&C value chain. This step identified nineteen types of PIPW and their corresponding generation points during the production processes. These qualitative insights provided granular information on waste characteristics not captured in aggregated national datasets, thereby strengthening the contextual accuracy of the MFA.

Company A, a leading polyester manufacturer located in West Java, operated in the upstream segment, covering polymerisation, fibre manufacturing, and spinning. It produced PSF, PFF, and textured yarn. Five major waste types were identified: off-grade pellets, filter residues, spinneret waste, off-specification yarn, and rejected fibre, primarily resulting from polymerisation and extrusion. Production activities were highly controlled and relied on automated machinery, with waste typically originating from machine maintenance, temporary shutdowns during national holidays, and disruptions to continuous operations.

Company B, also situated in West Java, represented a vertically integrated midstream producer encompassing spinning, texturising, fabric manufacturing, dyeing, and finishing. Similar to Company A, its production processes were highly controlled and largely automated, although process variability and differences in operational yield contributed to a broader waste profile. Waste was also generated due to human error, machinery disruptions, routine maintenance, and equipment shutdowns during holiday periods. In addition, the composition of the fibres further influenced both the volume and type of waste produced, particularly during the yarn-spinning stage. Field observations identified twelve distinct waste types: fibre preparation waste, fly fibre/dust, yarn waste, off-spec yarn, knitted fabric offcuts, knitted remnant, warp/weft scrap, leader fabric, woven trimming, coated selvedge trimming, defective dyed fabric, defective finished fabric.

Company C, an export-oriented garment manufacturer located in Central Java, operated exclusively in the downstream segment. Its core activities included pattern-making, fabric cutting, and garment assembly. High-technology applications were limited to pattern making and fabric cutting. Other tasks, such as material preparation, quality control, ironing, and packaging, were performed manually. The visit identified three main unwanted textiles: cutting waste, sewing waste, and end-of-roll waste. The cutting stage, identified as the key generation point, contributed 80% of the total waste. Additionally, the study found that fabric construction contributed to the waste production. Fabrics that are highly sleek and drapey pose a greater challenge for cutting and sewing.

A summary of each firm’s characteristics, including industrial scale, production location, product type, and waste categories, is presented in Supplementary Material S2. These empirical observations validated the MFA’s findings and supported categorising waste by origin and recyclability opportunity, providing a robust foundation for the subsequent circularity mapping. This approach ensured that the study captured comprehensive qualitative information on post-industrial waste.

2.2. Polyester Post-Industrial Waste Typology

2.2.1. Waste Type and Characteristics

Semi-structured interviews revealed that each PIPW stream exhibits distinctive physical and chemical properties, which vary across production segments. In the upstream stage, PIPW is primarily composed of homogeneous, textile, and non-textile residues with high polyester content. The polymerisation stage produced off-grade pellets that were thermoplastic and uncontaminated but were rejected due to melt-flow inconsistencies and filter residues, comprising burnt and degraded sludge from polymer filtration. Fibre manufacturing produced two kinds of waste: spinneret waste and rejected fibres. Spinneret, which, though physically solid, is thermally carbonised and considered non-recyclable. In contrast, rejected fibres appear structurally intact and chemically clean.

In the yarn spinning stage, fibre preparation waste consists of staple fibre fragments (laps and slivers) that remain uncontaminated, while yarn waste and fly fibre introduce greater variability in length and purity. The texturising stage contributes off-spec yarn, typically rejected for poor crimping or broken filaments, yet remains chemically suitable for recycling. In the midstream segment, waste exhibits moderate levels of contamination and increased structural complexity. Weaving and knitting processes produce knitted fabric offcuts, weft/warp scraps, and woven trimmings. They remain physically clean but vary in fibre content, geometry, and weave structure. In contrast, dyeing and finishing generate fabric waste that has undergone chemical treatments. Leader fabric has high dye loads; dyed fabric with defects exhibits visual inconsistencies; and coated selvedge trimmings contain resinous compounds that compromise recyclability.

In the downstream segment, garment manufacturing generates highly heterogeneous waste. Cutting waste and sewing waste are physically fragmented, colour-variable, and often inseparable. Additionally, end-of-roll waste from unused fabric inventory is identified as a distinct waste type at this stage. Details of the characteristics of each waste type, including generation points and technical descriptions, are presented comprehensively in

Table 3. Characteristics of post-industrial polyester waste.

No.	Production Chain	Sub Process	Waste Type	Key Characteristics
1	Polymerisation and fibre manufacturing	Polymerisation and fibre manufacturing	Off-grade pellets	Thermoplastic polyester pellets; high purity; rejected due to melt-flow or colour deviations.
			Filter residue	Burnt and degraded polymer sludge from filtration; contaminated, brittle, non-thermoplastic.
			Spinneret waste	Carbonised polyester residues from spinneret cleaning; thermally degraded; non-recyclable
			Rejected fibre	Continuous filaments rejected for strength or diameter defects; high polyester purity.
2	Yarn Manufacturing	Yarn spinning	Fibre preparation waste	Clean staple fibre fragments (laps, slivers); uniform structure; no chemical contamination.
			Yarn waste	Mixed-length polyester yarns from winding, moderate purity, low contamination.
		Texturising	Off-spec yarn	Short polyester yarns rejected for poor crimping or broken filaments; chemically clean.
3	Fabric Manufacturing	Knitting	Knitted fabric offcuts	Irregular knit fabric scraps; untreated; variable size and geometry.
			Knitting yarn remnants	Short, tangled yarns from spool changes; clean but physically complex.
		Weaving	Woven fabric trimmings	Selvedge and edge trimmings; physically clean; moderate weave complexity.
			Warp/weft scrap	Cut yarns removed post-weaving; clean, homogeneous, simple structure.
4	Wet Processing	Dyeing & Printing	Leader fabric	Initial dyed fabric; high dye load; structurally intact but chemically contaminated.
			Defective dyed fabric	Dyed fabric with colour or print inconsistencies; moderate chemical load.
		Finishing	Defective finished fabric	Fabric rejected due to finishing or coating flaws; resins present; fibre matrix intact.
			Coated selvedge trimmings	Heavily coated fabric edges; reduced recyclability due to compound layers.
5	Garment Manufacturing	Garment Manufacturing	Cutting waste	Mixed fabric offcuts; heterogeneous in colour, fibre blend, and geometry.
			Sewing waste	Entangled short threads from stitching; mixed colour; physically inseparable.
			End-of-rolls	Unused homogeneous fabric rolls; untreated; physically intact.

.

Material composition analysis reveals that blended-fibre waste constitutes the most dominant fraction of PIPW generated along Indonesia’s T&C manufacturing chain. Approximately 61% of total PIPW consists of blended fibres, 34% of pure polyester, and the remaining 5% of polymeric or non-textile materials. Blended-fibre waste is predominantly concentrated in the midstream and downstream stages of production, particularly in garment manufacturing, where cutting waste accounts for the largest share of the total volume of blended fibres. PIPW originating from fabric manufacturing and wet processing stages also predominantly contains blended fibres. Although the upstream yarn-spinning stage also generates waste streams containing blended fibres, such as fibre-preparation waste comprising PSF mixed with natural staple fibres.

In contrast, pure polyester waste is primarily concentrated in upstream processes, such as rejected fibre/filament and off-spec yarn, where material specifications are relatively well controlled, and fibre blending practices remain limited. Meanwhile, the polymeric or non-textile fraction mainly originates from polymerisation and fibre manufacturing processes, including off-grade pellets and filter residue. It represents only a minor share of total PIPW. A detailed breakdown is provided in Supplementary Material S3.

2.2.2. Recyclability Scoring

Based on the expert-based recyclability framework described in Section 4.3.2, nineteen identified PIPWs were classified into five tiers of recyclability. This classification reflects systematic differences in material quality, processing complexity, and potential for reintegration into circular textile pathways, thereby providing a structured basis for assessing the relative circular value of each waste stream.

The assessment results indicate a high level of consistency across expert evaluations. For all waste streams and assessment parameters, inter-expert score deviations did not exceed two points. Consequently, final recyclability scores were established through a facilitated consensus process, without applying the mean-based aggregation procedure specified in the protocol. The summarised inter-expert agreement for each waste category is reported in Supplementary Material S4.

Three waste streams were classified as highly recyclable: off-grade pellets, fibre preparation waste, and end-of-roll fabrics. These materials were characterised by high polyester purity, negligible contamination, and the absence of chemical finishing. Their uniform material properties render them technically compatible with closed-loop recycling pathways, direct reprocessing, or remanufacturing, with minimal pre-treatment requirements.

Six waste streams were assigned to the high–moderate recyclability category, including rejected fibre, off-specification yarn, yarn waste, warp and weft scrap, defective dyed fabric, and defective finished fabric. Although these wastes retained relatively high polymer integrity and functional performance, their utilisation as recycling feedstock generally required additional preparatory steps, such as mechanical disentanglement, fibre separation, or chemical cleaning, to enable effective fibre-to-fibre recycling or mechanical recovery.

The moderate recyclability category comprised knitting yarn remnants, knitted fabric offcuts, and woven fabric trimmings. These waste streams exhibited greater physical heterogeneity, including non-uniform fibre lengths, variable geometries, and complex material entanglement. Such characteristics increased handling complexity and pre-treatment demands, thereby constraining their suitability for high-value circular applications.

Waste streams classified as having moderate–low recyclability included leader fabric, coated selvedge trimmings, and cutting waste. Their reduced recycling potential was primarily attributable to chemical contamination from dyes, coatings, or adhesives, as well as the presence of complex fibre blends. These factors adversely affected both processability and economic viability, particularly with respect to reintegration into closed-loop textile systems.

Finally, the low recyclability category encompassed spinneret waste, fly fibre and dust, filter residue, and sewing waste. These streams were typically subject to advanced chemical degradation, severe physical fragmentation, or pronounced structural incoherence, rendering them incompatible with currently available recycling technologies. As a result, their end-of-life management remains confined mainly to incineration or landfill disposal. A summary of the recyclability scores and corresponding waste classifications is presented in

Table 4. Recyclability scoring of polyester post-industrial textile waste.

No.	Waste Type	MP	EF	TA	Total	Recyclability Category
1	Off-grade pellets	1	1	1	3	High
2	Fibre preparation waste	1	1	1	3	High
3	End-of-roll fabric	2	1	1	4	High
4	Rejected fibre/filament	1	2	2	5	High–moderate
5	Off-spec yarn	1	2	2	5	High–moderate
6	Yarn waste	2	2	2	6	High–moderate
7	Warp/weft scrap	2	2	2	6	High–moderate
8	Defective dyed fabric	3	2	2	7	High–moderate
9	Defective finished fabric	3	2	2	7	High–moderate
10	Knitting yarn remnants	2	3	3	8	Moderate
11	Knitted fabric offcuts	2	3	3	8	Moderate
12	Woven fabric trimmings	2	3	3	8	Moderate
13	Leader fabric	3	4	4	11	Moderate–low
14	Coated selvedge trimmings	4	4	4	12	Moderate–low
15	Cutting waste	4	4	3	11	Moderate–low
16	Spinneret waste	5	5	5	15	Low
17	Fly fibre/dust	5	5	5	15	Low
18	Filter residue	5	5	5	15	Low
19	Sewing waste	5	5	4	15	Low

.

2.2.3. Polyester Waste Typology

Building on the combined findings of waste characterisation and recyclability scoring, this study synthesised a structured typology of PIPW to elucidate the relationship between waste generation patterns and recyclability potential across the T&C production chain. The resulting typology classifies 19 distinct PIPW streams into five recyclability tiers—high, high–moderate, moderate, moderate–low, and low—as illustrated in Figure 2.

The typology reveals a clear stratification of recyclability along the production stages. Waste streams generated in upstream processes are predominantly high-recyclability streams, reflecting their high material purity, limited chemical treatment, and relatively uniform physical characteristics. In contrast, waste originating from downstream processes is primarily concentrated in the moderate–low and low recyclability tiers, where complex fibre blends, intensive finishing, and chemical contamination are more prevalent.

Midstream operations exhibit the most tremendous heterogeneity in recyclability outcomes. Waste streams such as fabric offcuts, defective dyed fabrics, and warp and weft scraps span the high–moderate to moderate tiers, indicating variable material quality and processing requirements. This diversity reflects the transitional position of midstream activities, where increasing material transformation begins to constrain recyclability without uniformly precluding higher-value recovery pathways.

Overall, the waste typology provides an integrated representation of how the potential for recyclability systematically declines along the production chain as material complexity and contamination increase. By consolidating waste characteristics, generation points, and recyclability performance into a single analytical construct, the typology offers a coherent synthesis of the study’s empirical findings.

2.3. Potential Circularity Map (Scenario A)

The circularity potential map under Scenario A visualises the distribution of PIPW across recyclability classes EoL pathways, integrating material composition, recyclability performance, and recovery routing. As shown in Figure 3, the map is organized into three vertically aligned sections that collectively illustrate how the potential for circularity evolves along the waste hierarchy.

The upper section classifies 572 kilotonnes of PIPW identified through the MFA into five categories of recyclability. Pie charts accompanying each category indicate the material composition: blue represents pure polyester, orange denotes blended fibres, and green indicates non-textile or polymer materials. This visualisation highlights the increasing dominance of blended materials as recyclability declines.

The middle section depicts the allocation of waste flows from each recyclability category to six EoL pathways: remanufacturing, closed-loop recycling, open-loop recycling, repurposing, incineration, and landfilling. Pathways are arranged according to a value-retention hierarchy, progressing from higher to lower value recovery [11,32,33]. Flow colours correspond to recyclability categories, dark green (high), dark blue (high–moderate), yellow (moderate), purple (moderate–low), and red (low). In contrast, the magnitude of each flow is indicated by labelled mass values (kt). The lower section aggregates the total waste volume directed to each EoL pathway, enabling a comparative assessment of recovery outcomes under Scenario A.

The resulting distribution indicates that the moderate–low recyclability category accounts for the largest share of PIPW (281 kt), followed by high–moderate (108 kt), high (68 kt), low (64 kt), and moderate (51 kt). Blended fibres dominate most recyclability classes, whereas polymer-rich fractions are most prominent in the high (28%) and low (16%) categories. The highest pure polyester content is in the high–moderate category (41%), and the lowest is in the high category (18%).

Among recovery routes, open-loop recycling receives the largest volume of PIPW (188 kt), with approximately 73% originating from the moderate–low recyclability category. Repurposing accounts for 177 kt, of which approximately two-thirds is also associated with the same category. Closed-loop recycling accounts for the smallest share (36 kt), primarily sourced from high, high–moderate, and moderate recyclability streams. Remanufacturing, by contrast, accommodates a substantial volume (75 kt), primarily composed of high- and high-moderate-quality feedstock.

Allocation of waste streams to the remanufacturing pathway was conducted selectively, as not all fractions within the high- and high–moderate recyclability categories met the technical requirements of this valorisation route. A waste fraction was classified as eligible for remanufacturing only if it satisfied the following key criteria: (i) retention of textile physical form (fabric or yarn), (ii) sufficient structural integrity for reassembly and downstream textile processing, (iii) low levels of degradation and contamination, and (iv) compliance with minimum functional dimensional requirements for garment production. Based on these criteria, approximately 19 kt from the high-recyclability category, primarily end-of-roll fabric, were identified as suitable for recovery into apparel products, particularly by micro- and small-scale manufacturing enterprises.

Within the high–moderate recyclability category, approximately 56 kt of waste was identified as having potential for allocation to remanufacturing pathways, including yarn waste, defective dyed fabric, and defective finished fabric. The allocation of yarn waste to remanufacturing was selective, limited to yarns that retained sufficient mechanical integrity and met the minimum physical quality requirements for downstream textile processing. Specifically, yarns were considered eligible only when preserved in continuous package form and compliant with the quality requirements stipulated in the Indonesian National Standard (SNI 08-0034-2004 and SNI 1790-2010-2017) [38,39], which are widely adopted by domestic textile manufacturers as minimum quality benchmarks, particularly for tensile strength (tenacity), evenness level, and acceptable imperfection limits for blended or polyester yarns. These criteria therefore serve as explicit screening thresholds that distinguish remanufacturing-eligible streams from streams directed to other recovery or disposal pathways.

In contrast, yarn waste exhibiting signs of mechanical degradation, excessive unevenness, high levels of imperfection, severe entanglement, or systematic fragmentation into short segments was excluded from remanufacturing pathways and instead allocated to incineration or landfilling, due to the elevated risk of process failure and deterioration in final product quality. Meanwhile, defective dyed and finished fabrics characterised by high contamination levels or failure to meet minimum functional dimensional requirements for garment assembly were directed to repurposing pathways, in which the material’s functional value could still be preserved without requiring reintegration into the conventional garment production cycle. Approximately 45 kt of PIPW is allocated to incineration, while an estimated 56 kt, predominantly from the low-recyclability category, is directed to landfill. The estimated allocation of PIPW across the six EoL pathways under Scenario A is summarised in Supplementary Material S5.

2.4. Potential Redirection of Post-Industrial Polyester Waste to Chemical Recycling (Scenario B)

Scenario B was developed to explore the potential to enhance the value of PIPW through technically feasible, selective reallocation from lower-value recovery pathways, relative to the baseline recyclability-based allocation framework defined under Scenario A, while preserving material flows already assigned to higher-value retention routes. The analysis shows that a total of 184 kilotonnes of PIPW could potentially be reallocated to chemical recycling, comprising open-loop recycling (85 kt), repurposing (6 kt), incineration (15 kt), and landfilling (18 kt). The distribution of reallocations across recovery pathways is presented in

Table 5. Waste reallocation and potential for chemical recycling.

End-of-Life Pathways	Scenario A (kt)	Scenario B (kt)	Reallocation (kt)
Remanufacturing	75	75	0
Closed-loop recycling	36	36	0
Open-loop recycling	188	103	85
Repurposing	172	106	66
Incineration	45	30	15
Landfilling	56	38	18
Chemical recycling	0	184	184

.

Further analysis by recyclability category indicates that approximately 121 kilotonnes of the total feedstock redirected to chemical recycling originate from the moderate–low category. Fabric cutting waste constitutes the largest share, representing 58% of the total reallocation potential. This volume primarily derives from waste that is technically incompatible with mechanical recycling due to colour heterogeneity and blended fibre content, and contains minimal resin content that would interfere with depolymerisation catalysts. Additional potential arises from the moderate category (28 kt), primarily from woven selvedge trimmings, knitted fabric offcuts, and knitting yarn remnants, which exhibit high purity, low contamination, and a high polyester content. This scenario also redistributes 19 kt of high–moderate recyclability waste, mainly warp/weft scrap and yarn waste. A total of 12 kt of sewing waste, representing the low-recyclability group, shows potential for chemical recycling due to its relatively high polyester content, solid textile form, and minimal non-textile contamination. Additionally, this scenario could divert at least 5 kt of high-recyclability waste, such as off-specification pellets, from open-loop recycling. The estimated reallocation of PIPW Scenario B is summarised in Supplementary Material S6.

3. Discussion

3.1. Pseudo-Circularity as a Structural Condition in Indonesia’s Polyester Textile System

This study reveals that Indonesia’s T&C industry is trapped in a state of pseudo-circularity, in which more than 188 kilotonnes of potentially valuable waste are annually downcycled due to a systemic failure to invest in closed-loop infrastructure and source-level segregation. Within the analytical framework of this study, pseudo-circularity is operationally defined as a configuration in which PIPW flows are quantitatively diverted from incineration or landfill, yet qualitatively fail to preserve material value, reintegrate into T2T production cycles, or meaningfully substitute for virgin fossil-based polyester. [40]. From an industrial ecology perspective, this condition reflects an inefficient industrial metabolism characterised by increasing material entropy along the production chain [41]; consequently, although approximately 60% of PIPW is absorbed by open-loop recycling and repurposing routes under Scenario A, only about 6% is effectively returned to closed-loop production cycles.

Material integrity erosion primarily arises from the absence of systematic segregation or pre-sorting practices at the production-floor level. Without source-level segregation, PIPW is frequently commingled with non-textile residues (e.g., cardboard, paper, and plastics) or with textile waste streams characterised by heterogeneous fibre compositions, colourations, and geometrical configurations [24]. Such commingling substantially increases sorting complexity, undermines feedstock homogeneity, and ultimately limits the technical feasibility of effective T2T recycling [42]. Concurrently, waste traceability is progressively compromised, impeding due diligence, regulatory compliance, and seamless integration into formalised waste supply chains [43]. Consequently, materials that are theoretically recyclable and economically valuable undergo qualitative value degradation, as they no longer meet the stringent technical specifications required for high-quality T2T recycling processes. Empirical evidence from prior studies indicates that the implementation of source-level segregation practices by textile and apparel manufacturers in Vietnam and China has significantly elevated post-industrial textile waste recycling rates to approximately 60–80% [23,44].

This manifestation of superficial circularity is further reinforced by systemic underinvestment across multiple layers of closed-loop recycling infrastructure. At the upstream stage, the absence of standardised and integrated collection and reverse logistics systems, coupled with a persistent reliance on informal PIPW trading networks, facilitates premature mixing of waste streams, erodes traceability, and reduces material purity before recovery. These structural deficiencies are compounded by insufficient investment in advanced sorting facilities and quality assurance systems capable of discriminating waste streams by fibre type, colour, and contamination intensity [45]. As a result, recyclers are exposed to elevated feedstock uncertainty, undermining process stability, yield optimisation, and the economic viability of closed-loop recycling pathways [46].

Downstream, existing technological capacity remains dominated by low-value mechanical recycling pathways, while closed-loop recycling infrastructure, particularly chemical recycling, has yet to develop at a commercial scale or be integrated with domestic waste streams. The absence of technical standards and quality specifications for recycled feedstock and intermediate products further weakens market signals and elevates investment risk. Economically, high capital requirements, long payback periods, and the lack of fiscal incentives or dedicated financing mechanisms encourage firms to maintain low-risk recovery options such as open-loop recycling and disposal [47]. Fragmented governance arrangements and weak cross-sectoral institutional coordination, including the limited operationalisation of effective EPR frameworks for post-industrial textile waste, ultimately reinforce conditions of structural lock-in. Collectively, these factors inhibit the formation of a functional T2T recycling ecosystem and explain why the existing system continues to reproduce patterns of pseudo-circularity, despite the substantial availability of recoverable material.

Accordingly, pseudo-circularity in Indonesia’s polyester textile system can be understood as the outcome of deficiencies in the circular system’s design. The dominance of low-value recovery pathways demonstrates that diverting waste from final disposal does not automatically yield substantive circularity in the absence of material segregation, quality assurance, and infrastructure capable of retaining value. These findings underscore that quantitative increases in recycling rates, without structural transformation in material governance and investment in closed-loop infrastructure, risk perpetuating the illusion of circularity and sustaining continued dependence on virgin, fossil-based polyester inputs.

3.2. The Garment Manufacturing Sector Is the Primary Contributor to PIPW

A key finding of this study is the predominance of waste generation in the garment manufacturing sector, which accounts for more than 56% of total PIPW, driven by structural inefficiencies and technological disparities. The primary source of inefficiency is the cutting process [1,48,49], which results in excessive fabric offcuts due to suboptimal pattern layout [50,51]. Although large-scale manufacturers have adopted computer-aided design (CAD) systems, automated fabric spreading, automated cutting machines, high-speed laser cutting, and ultrasonic cutting technologies, achieving material efficiency rates of up to 88% [52]. The complete elimination of cutting waste remains challenging. In contrast, SMEs largely lack access to such advanced technologies due to high capital requirements. Their production systems generally rely on basic automated cutting machines, with only limited adoption of CAD tools. MFA findings indicate that approximately 51% of material inputs entering the garment manufacturing stage are processed by SMEs [3], suggesting that this segment contributes disproportionately to waste generation compared with large-scale manufacturers.

In addition, intrinsic material characteristics, such as slipperiness, high drapability, and patterns or textures, further increase cutting complexity and contribute to higher waste volumes [49]. Waste characteristics within the garment manufacturing sector are further complicated by the dominance of blended fibres, which account for approximately 61% of total PIPW, whereas pure polyester waste accounts for only about 34%. The presence of fibre blends, colour variability, and residual finishing chemicals significantly reduces compatibility with high-value recovery pathways, particularly closed-loop mechanical recycling, and constrains the availability of suitable feedstock in the absence of systematic source segregation [2,24].

3.3. Limitations of Mechanical Recycling and the Reproduction of Low-Value Pathways

This study confirms that reliance on mechanical recycling, as the currently available technology in Indonesia, entails inherent limitations when applied to increasingly complex polyester textile waste streams. Mechanical recycling requires relatively homogeneous feedstock in terms of fibre type, colour, and contamination levels. Waste streams characterised by blended fibres, dark colours, and residual finishing chemicals demand intensive sorting and purification processes that are often economically unviable or technically unavailable under existing industrial conditions [53,54,55].

Moreover, mechanical processing degrades material quality through repeated cutting, shredding, and fibre opening, reducing mechanical strength and increasing challenges during re-spinning [20,56]. As a result, recycled outputs typically meet specifications only for lower-value applications, such as coarse yarn products, or require blending with virgin polyester to achieve acceptable performance [57]. Consequently, their capacity to function as substantial substitutes for primary raw materials remains limited [9,19]. Several studies have demonstrated that these structural constraints render mechanical recycling insufficient as a standalone solution for blended and fragmented polyester textile waste, although it remains appropriate for specific homogeneous waste fractions [35,51].

Importantly, these limitations imply that mechanical recycling does not merely face technical constraints, but structurally reinforces low-value recovery pathways within the existing system. By consistently producing downgraded materials that require virgin polyester supplementation, mechanical recycling sustains dependence on fossil-based inputs while simultaneously contributing to the statistical appearance of circularity. In this way, mechanical recycling operates as a stabilising mechanism of pseudo-circularity, diverting waste from landfill but progressively degrading material value rather than retaining it across successive cycles.

3.4. Feasibility of Chemical Recycling as a Valorisation Pathway

The strengthening of Scenario B in this study is not driven solely by the availability of chemical recycling technologies, but rather by a systemic need to escape the pseudo-circularity trap reproduced by the dominance of low-value recovery pathways. Within the valorisation hierarchy framework, chemical recycling is positioned as a selective, high-value upcycling route that preserves material value at the molecular level and enables functional substitution of virgin, fossil-based polyester within the textile value chain. Accordingly, Scenario B is not conceived as an “additional option”, but as a structural intervention aimed at correcting the mismatch between the characteristics of PIPW in Indonesia and the limitations of currently dominant recovery pathways.

Based on the waste composition identified through the MFA, characterised by the predominance of blended fibres, colour variability, and residues from dyeing and finishing processes, the most relevant chemical recycling routes include glycolysis, methanolysis, and hydrolysis, as well as solvent-based selective separation approaches for blended fibre waste [9,58]. Glycolysis is widely regarded as the most technologically mature route for textile polyester waste, as it operates under relatively moderate conditions and produces bis(2-hydroxyethyl) terephthalate (BHET), which can be repolymerised into high-quality PET [9,59,60]. Methanolysis and hydrolysis, particularly in catalytic or green-solvent configurations, enable more complete depolymerisation to TPA and MEG, and are therefore more tolerant of molecular degradation and intrinsic viscosity variations commonly observed in textile polyester fibres [9,61,62,63]. These characteristics render the three routes conceptually aligned with the structure of Indonesian PIPW, which is dominated by complex waste streams generated during garment manufacturing.

Nevertheless, the literature indicates that chemical recycling is subject to stringent feedstock requirements, particularly with respect to contamination levels, dye content, residual finishing chemicals, and fibre blend complexity [9,19,34,35]. Disperse dyes, flame retardants, and finishing agents strongly bound to the fibre matrix can reduce reaction selectivity, lower monomer yields, and increase the need for pre-treatment and purification [9,21]. Within the recyclability typology developed in this study, waste streams with high or high–moderate recyclability are the most compatible with glycolysis and methanolysis routes, owing to their higher polyester purity and more controlled contamination levels. In contrast, some waste streams in the moderate, moderate–low, and low recyclability categories generally require combinations of chemical pre-treatment, selective separation, or more aggressive solvolysis routes, which directly increase technical complexity and processing costs [35,58,64].

A further challenge lies in ensuring a consistent supply of waste that meets these quality requirements to optimise value retention. Although post-industrial waste is, in principle, more suitable for closed-loop recycling, source-level segregation and waste-sorting systems are critical to ensuring standardised, high-quality feedstock [24,42,65,66]. At present, most textile firms in Indonesia have not fully implemented waste management practices that support such segregation. Sorting activities largely depend on manual separation by collectors, without access to adequate sorting facilities. This situation is exacerbated by weak textile waste governance, including the lack of enforcement of EPR obligations and the absence of regulatory frameworks recognising waste as a secondary resource, which together constrain accessibility. Moreover, fragmentation within Indonesia’s industrial structure further complicates the development of sustainable circular supply chains, increasing logistics costs and limiting economies of scale in waste collection and recycling.

From an economic perspective, chemical recycling requires substantial capital investment in technology, research, and development [35,67]. Operationally, it also entails higher costs than mechanical recycling, particularly in terms of energy and chemical consumption [20]. In addition, market demand for recycled polyester products remains primarily driven by global brands that have circular business models [68,69]. These brands typically orchestrate their supply chains by imposing strict material quality standards and certification requirements, which pose significant challenges for suppliers, including those in Indonesia. By contrast, domestic demand for recycled textile products remains limited due to low public awareness of circular textiles and the lack of policy instruments to stimulate markets for recycled materials. As noted by Dahlbo et al., governments play a critical role in market creation for recycled materials, for example, through public procurement policies [48]. Consequently, cross-sectoral collaboration is essential to overcoming these systemic barriers.

From an infrastructural and environmental perspective, chemical recycling also involves significant energy and emission trade-offs [70]. Depolymerisation processes typically require high temperatures, chemical solvents, and intensive purification steps, with major hotspots associated with reactor energy consumption, solvent regeneration, and post-reaction wastewater treatment [61,63,71]. Without a systemic evaluation, there is a risk that chemical recycling merely shifts environmental burdens from the end-of-life stage to the processing stage, potentially creating a new form of pseudo-circularity that prioritises material retention while neglecting net environmental impacts. Therefore, further life cycle assessment (LCA) and techno-economic analysis (TEA) are required to comprehensively evaluate the technical, economic, and environmental feasibility of this valorisation pathway in Indonesia, and to ensure that it contributes meaningfully to breaking the textile industry out of the pseudo-circularity trap and advancing towards genuine sustainable development.

Beyond recycling-based valorisation pathways, recent circular-economy literature emphasises that reducing structural dependence on fossil-based inputs in polyester systems also requires complementary upstream strategies focused on material sourcing and feedstock selection. Bio-based polyester represents one such pathway, utilising renewable, sustainable agricultural feedstocks such as corn and sugarcane to substitute fossil-derived virgin polyester [72]. Three bio-sourced polymer routes are commonly identified as compatible alternatives to conventional PET: bio-based PTA (bio-PTA), bio-based Polylactic Acid (bio-PLA), and bio-based Polytrimethylene Terephthalate (bio-PTT), each exhibiting different substitution potentials in polyester production systems.

These bio-based polymers have been reported to exhibit mechanical, physical, structural, and thermal properties comparable to those of conventional polyester, and, in specific formulations, offer the additional advantage of biodegradability [73]. However, from an economic perspective, investment requirements for bio-based polyester production remain substantial. Berger and Pfeifer revealed that the establishment of stand-alone bio-polyester production facilities often fails to achieve a positive net present value, with economic feasibility improving only when such facilities are integrated into existing biorefinery or recycling infrastructures [74]. Moreover, comparative assessments suggest that recycling-based polyester recovery remains more economically favourable, as operational costs for bio-PTA and bio-based MEG production tend to be higher due to increased process complexity and resource intensity [74].

From an environmental perspective, bio-sourcing pathways have the potential to reduce greenhouse gas emissions relative to conventional fossil-based polyester [73,74] and have been highlighted as a promising valorisation route to support zero-waste ambitions and circular economy objectives [75]. Nevertheless, the environmental performance of bio-based polyester is not inherently superior. Several studies caution that biomass-based production, particularly when relying on first-generation feedstocks, may exacerbate other environmental burdens, including land use change, water consumption, and eutrophication [72]. Consequently, bio-based polyester cannot be regarded as a risk-free or universal substitute for fossil-based polyester.

In the Indonesian context, bio-based polyester is therefore most appropriately positioned as a selective, long-term complementary strategy, rather than an immediate replacement pathway. Future development efforts should prioritise second-generation biomass and agro-industrial residues to minimise trade-offs with food systems and environmental pressures. When deployed alongside chemical recycling, such upstream valorisation pathways may help reduce fossil fuel dependence and enhance the resilience of the polyester material system, while acknowledging the current technical, economic, and environmental limitations of bio-based alternatives.

3.5. Comparison with Other Studies

Previous studies have reported post-industrial waste ratios across T&C production chains in several major exporting countries. Although most of these studies do not explicitly distinguish between fibre types, such as polyester, they provide a useful benchmark for comparing production efficiency and waste-generation patterns across national contexts. As summarised in

Table 6. Comparison of waste ratios across T&C production chains in several major exporting countries.

Country	Production Chain				Source
	Yarn Manufacturing (%)	Fabric Manufacturing (%)	Wet Processing (%)	Garment Manufacturing (%)
Indonesia	5	7	4	18	Author
Bangladesh	11	2	N/A	7	[6]
Vietnam	N/A	N/A	N/A	18	[48]
China	N/A	N/A	N/A	14	[27]

, Indonesia exhibits relatively low waste ratios at the yarn manufacturing stage compared with Bangladesh, but higher waste ratios at the fabric and garment stages, indicating uneven performance along the value chain.

Differences in yarn waste ratios between Indonesia and Bangladesh can largely be explained by fibre composition. Bangladesh’s spinning industry is dominated by cotton, which contains inherent impurities such as short fibres and seed fragments that must be removed during processing, resulting in higher waste ratios [6,76]. This observation is consistent with the study’s findings, which show elevated waste ratios in spinning processes involving cotton–polyester blends. In contrast, Indonesia’s lower yarn waste ratios reflect the dominance of synthetic fibres in its spinning operations. However, Indonesia’s comparatively higher waste generation at the fabric and garment stages points to structural inefficiencies associated with process intensity and product characteristics. Fabric production in Indonesia is predominantly based on woven textiles, which require higher yarn tension and are more susceptible to yarn breakage than knitted fabrics. By comparison, Bangladesh’s fabric sector is highly specialised in knitted products, where lower mechanical stress reduces waste generation [77,78].

A similar pattern emerges in garment manufacturing. As shown in Table 2, Bangladesh has lower garment-waste ratios than China and Vietnam, despite its large export volumes. This apparent efficiency is closely linked to product specialisation, as Bangladesh’s garment industry focuses primarily on basic, high-volume products with simple cutting patterns, such as T-shirts and standard trousers, which achieve high market efficiency and generate relatively low cutting waste [79]. In contrast, China and Vietnam have increasingly shifted toward higher-value, more complex apparel segments, including technical garments, sportswear, and multilayer fashion products, in which increased pattern complexity inherently reduces fabric utilisation efficiency and results in higher waste ratios per unit of output [76].

Importantly, higher waste ratios in China and Vietnam do not imply weaker circular performance. On the contrary, both countries demonstrate substantially stronger post-industrial waste management and recycling systems. In China, approximately 80% of post-industrial textile waste is recycled through internal reuse or collaboration with licensed recycling firms, supported by advanced mechanical and emerging chemical recycling technologies, widespread source segregation, and vertically integrated industrial structures [27,44]. Vietnam follows a similar, though less mature, trajectory, with approximately 60% of post-industrial textile waste recycled, primarily via mechanical and thermomechanical processes, while chemical recycling remains under development. Geographic clustering of manufacturers, collectors, and recyclers within industrial zones further facilitates coordination and material flow control [23].

By contrast, Bangladesh, despite its low garment waste ratios, lacks formalised collection, traceability, and recycling systems for post-industrial textile waste. Waste flows are largely managed through informal channels, and recycling activities are predominantly oriented towards low-value downcycling [78]. This comparison highlights a critical insight: low waste generation does not automatically translate into high levels of circularity in the absence of effective waste governance, waste segregation, and recycling infrastructure.

From a governance perspective, the European Union provides an additional benchmark. Approximately one-third of textile waste collected in the EU originates from post-industrial sources, supported by formal segregation systems and extended producer responsibility (EPR) frameworks [1]. Nevertheless, recycling capacity remains constrained by high processing costs and limited economic incentives [1,80], illustrating that even in highly regulated contexts, circularity outcomes depend not only on policy frameworks but also on market viability and scalable recycling pathways

3.6. Implications and Recommendations

The study further underscores that challenges to circularity in emerging economies are shaped not only by technological availability but also by institutional fragmentation, infrastructural limitations, and governance gaps. The widespread use of blended fibres, coupled with the absence of robust segregation and quality-assurance infrastructure, severely constrains the potential for high-value recovery, even for technically recyclable materials. These findings extend the theoretical framework of industrial symbiosis by situating it within the fragmented and heterogeneous supply-chain configurations characteristic of developing-country contexts [81]. Notably, the empirical dominance of moderate–low recyclability waste and blended fibre streams identified in this study provides a material basis for rethinking recovery strategies beyond conventional mechanical recycling. In addition, the significant role of SMEs in both waste generation and repurposing highlights the need for inclusive, capacity-building policies that translate circular economy principles into practicable transition pathways rather than idealised system models.

Notably, the findings from Scenario B indicate that approximately 184 kt of polyester waste currently directed into low-value recovery pathways could be conditionally redirected towards chemical recycling, revealing a substantial feedstock opportunity for valorisation-oriented technologies. This result reinforces the notion that systemic reforms must not only improve source segregation and mechanical recovery performance, but also enable the selective integration of chemical recycling pathways capable of handling heterogeneous and blended waste streams that are structurally incompatible with conventional fibre-to-fibre recycling. Importantly, chemical recycling is positioned in this study not as a universal solution, but as a complementary pathway whose viability depends on feedstock quality, volume consistency, and supporting institutional arrangements. Without these enabling conditions, chemical recycling risks reproducing pseudo-circular outcomes in a more technologically complex configuration.

To catalyse a genuine transition towards sustainable circularity in Indonesia’s T&C industry, this study proposes a tiered and actionable strategy. As an immediate priority, the government should mandate waste segregation at source, beginning with large-scale garment manufacturers, which are the primary generators of heterogeneous, low-recyclability waste. Implementation measures should include pre-sorting by fibre type, colour, and finishing treatment; standardised waste classification protocols; real-time waste flow reporting; and periodic compliance audits embedded within existing environmental management systems.

In the medium term, fiscal incentives should be introduced to support SMEs in adopting fabric optimisation tools, CAD systems, and semi-automated cutting technologies, which are critical for improving material efficiency and reducing avoidable cutting waste. Incentive schemes should also extend to waste handlers and recyclers, including grants for automated sorting technologies and co-investment mechanisms for upgrading material pre-treatment and quality-control capabilities [65,66,82]. Moreover, public–private partnerships should be mobilised to establish pilot-scale chemical recycling facilities, accompanied by shared infrastructure for feedstock preparation, solvent recovery, and quality assurance, particularly for complex and blended waste streams identified as viable under Scenario B.

As a long-term strategy, circular design principles must be embedded within national industrial standards and regulatory frameworks. It includes mandatory disclosure of fibre content and finishing, design-for-recyclability guidelines, and regulatory disincentives for non-recyclable or excessively blended textile products. In parallel, sustained research and development support is required to optimise chemical recycling processes, qualify recycled outputs for textile-grade applications, and develop secondary markets for recycled chemicals and fibres. Overall, the study’s implications indicate that advancing textile circularity in Indonesia is less a question of recycling capacity than of strategically aligning waste characteristics, recovery technologies, and governance frameworks.

3.7. Limitations and Future Research

Several limitations of this study should be acknowledged, and directions for future research delineated. First, the MFA was constructed using aggregated national production and trade statistics, complemented by site visits to three representative T&C firms and expert-derived estimates. Although this mixed-source approach ensures internal consistency at the national level, it may not fully capture the heterogeneity of firms in Indonesia’s textile sector, particularly micro- and small-scale enterprises, potentially yielding conservative estimates of certain waste flows.

Second, waste categorisation in this study was based primarily on physical form, process origin, and operational characteristics, rather than detailed polymer composition, additive content, or finishing chemistry. This necessary simplification may affect the precision of recyclability assessments, especially for chemically complex or multi-layered textile materials. Future studies incorporating polymer-level characterisation would enable more granular evaluation of recovery feasibility.

Third, several modelling assumptions were required due to data constraints, including excluding domestically produced PET pellets from the textile system boundary and generalising fibre blending practices at the spinning stage. While these assumptions reflect structural features of Indonesia’s vertically integrated polyester industry and were mitigated through data triangulation, residual uncertainty at the national scale remains unavoidable. In addition, the MFA represents a static snapshot for a single reference year (2023) and does not account for temporal dynamics, stock accumulation, or demand-driven variability. The absence of uncertainty ranges or sensitivity analysis, therefore, constitutes a further limitation.

Fourth, Scenario B, which explores the potential redirection of PIPW towards chemical recycling, was informed primarily by the literature and a limited number of expert judgements. While sufficient for exploratory analysis, broader engagement with industry practitioners, policymakers, technology providers, and waste management actors would strengthen the robustness and contextual relevance of future scenario development.

Finally, this study does not explicitly assess regulatory feasibility, investment readiness, or behavioural responses associated with implementing advanced recycling pathways. Consequently, the findings should be interpreted as analytical insights into structural mismatches between waste characteristics and prevailing recovery configurations, rather than as immediate implementation prescriptions. Future research should build on this baseline by incorporating probabilistic MFA, integrated techno-economic and life-cycle assessments of chemical recycling routes, intensity-based indicators where data permit, and participatory scenario development across a wider range of stakeholders.

4. Materials and Methods

4.1. Research Design and System Boundaries

This research employed a mixed-methods approach, combining MFA with qualitative data from site visits and expert interviews. The MFA was utilised to trace the flows of polyester through the T&C manufacturing chain, capturing inflows, outflows, and stock (waste) in accordance with mass-balance principles [1,13,29]. This approach facilitated a comprehensive mapping of material flows within the textile system, enabling the national-scale quantification of PIPW.

The geographical system boundary is defined at the national level and encompasses polyester-based T&C manufacturing activities in Indonesia. The temporal boundary corresponds to calendar year 2023, the most recent year for which complete and consistent national production and trade data were available at the time of analysis. Functionally, the system is defined as the polyester-based T&C manufacturing system and is analysed using a gate-to-gate approach within the MFA framework. The analysis focuses on material flows within the manufacturing stages, including polymerisation and fibre manufacturing, yarn manufacturing (spinning and texturising), fabric manufacturing (weaving and knitting), wet processing (dyeing, printing, and finishing), and garment manufacturing. Downstream segments, such as nonwovens, home textiles, technical textiles, and other non-apparel products, are excluded because they are of negligible relevance to T2T recycling practices [1].

Site visits and interviews were conducted as triangulation tools to enhance the robustness of the MFA results. Site visits facilitated the collection of in-depth empirical data concerning the T&C production system, waste generation mechanisms, waste characteristics, and in-house recycling opportunities. Interviews proceeded in four sequential phases. First, semi-structured interviews were conducted with three key informants to validate the quantitative data and the MFA framework. Second, semi-structured interviews were conducted with nine key respondents to explore the critical production system, waste characteristics, and the feasibility of internal recycling. Third, an FGD was conducted with nine participants, including T&C producers, recyclers, and a textile academic, to assess the potential for circularity, establish a waste typology, and estimate waste distribution across six EoL routes (Scenario A), which subsequently served as the quantitative baseline for the exploratory reallocation analysis in Scenario B. Finally, a semi-structured interview was conducted with a textile academic to estimate the reallocation of waste from low-value to chemical recycling (Scenario B). The principal outcome of this study is a data-driven map of circularity potential for PIPW and the feedstock gap for the chemical recycling pathway.

4.2. Data Collection

This study utilised mixed data, comprising both quantitative and qualitative inputs, drawn from multiple sources and collected using complementary methods. The detailed data collection procedures are described in the following subsections.

4.2.1. Quantitative Data

Three distinct quantitative datasets were employed to estimate the mass of PIPW generated across the T&C manufacturing chain. National production data available only up to 2023 were obtained through formal requests submitted to the Ministry of Industry of the Republic of Indonesia (MoI). In parallel, data on imports of raw materials and intermediate textile products, as well as exports of polyester-based T&C products, were retrieved from the official statistics of BPS-Indonesia (www.bps.go.id), the official national statistical authority. These datasets were incorporated to derive total raw material consumption for each chain segment and to reduce potential bias in waste calculations [29,48].

To enhance the robustness and internal consistency of the MFA model, several key assumptions were established based on a synthesis of the literature and expert justification:

• Domestically produced PET pellets are assumed to be diverted from the textile manufacturing chain and are therefore treated as outflows to non-textile sectors in the MFA. This assumption reflects the operational structure of Indonesia’s polyester industry, in which the eight major polyester fibre producers are vertically integrated with petrochemical operations and directly process MEG and PTA into PSF, partially oriented yarn (POY), or fully drawn yarn (FDY) through continuous polymerisation. Although PET pellets may be generated during polymerisation, expert informants confirmed that they are predominantly consumed internally within integrated facilities, with the remainder allocated to non-textile applications. Accordingly, in this study, PET pellets are tracked at the polymerisation stage as non-textile outflows and excluded from downstream textile MFA calculations. This treatment preserves a textile-specific system boundary, ensures mass balance consistency, and avoids double-counting of material flows.
• It is assumed that the stream of the PSF entering the yarn spinning stage is blended with other fibres, such as cotton, rayon, etc. This assumption reflects standard manufacturing practice adopted to balance material properties, cost efficiency, and fabric performance. Site visits and expert interviews confirmed that the production of pure PSF yarn is exceedingly rare in Indonesia and is generally limited to niche applications with relatively small production volumes.
• Garment output is estimated using a standard conversion factor to satisfy the mass-balance requirements of the MFA. One garment unit, represented by a medium-sized T-shirt, is assumed to require approximately 1.5 m or 0.4 kg of fabric. This proxy is widely recognised in industry benchmarking and was corroborated by expert interviews and relevant technical literature [48].
• The study assumes no stock accumulation (i.e., net stock change = 0), meaning that all inputs are processed within the same observation period. This assumption aligns with the steady-state approach used in annual MFA studies [29].

4.2.2. Qualitative Data

A multi-phase qualitative data collection strategy was implemented sequentially, as outlined in Supplementary Material S7. Although the MFA is based on 2023 industrial data, the qualitative data were collected in 2025 to validate and contextualise the material-flow assumptions. It encompassed three site visits, thirteen semi-structured interviews, and an FGD with nine key informants. Field visits were conducted at: (1) an integrated polymerisation and fibre-spinning mill in West Java; (2) an integrated textile manufacturing company, encompassing spinning to fabric finishing in West Java; and (3) an export-oriented garment manufacturer in Central Java. These companies were selected purposively based on three principal criteria: high production volume, representativeness of core manufacturing stages, and willingness to disclose operational data transparently. This strategy aimed to ensure the representativeness of polyester flows across the national production landscape and to obtain robust primary data to strengthen the MFA model. The approach aligns with the principle of information-rich cases in qualitative research, which emphasises selecting units of analysis that can provide deep insights into the studied phenomenon [83].

The semi-structured interviews were conducted in three phases. First, interviews with three key actors with high authority over national textile policy and production: the Director of Textile, Leather and Footwear Industries, MoI; the Chairman of the Indonesian Synthetic Fibre Producers Association (APSYFI); and the Secretary General of the Indonesian Textile Association (API). These informants were selected for their strategic positions and comprehensive knowledge of material flow dynamics and the national T&C industry structure; they thus provided initial validation of the quantitative data, the MFA framework, and the modelling assumptions. Second, interviews were conducted with nine informants from various subsectors of the value chain, including six managers of four T&C manufacturers (representing the upstream, midstream, and downstream sectors); two chairpersons of textile industry associations; and a textile academic. The interviews comprised three principal modules: (1) T&C and waste production processes; (2) waste types and their characteristics; and (3) internal recycling opportunities. Additionally, the interviews confirmed findings from the site visits and the MFA results. Third, a semi-structured interview was conducted with a textile academic to estimate the potential reallocation of feedstock from low-value pathways into the chemical recycling route in scenario analysis.

An FGD involved nine key informants representing three stakeholder clusters: the T&C producers, waste handlers (collectors and recyclers), and textile experts. The participant composition was purposively selected to ensure diversity of technical and operational perspectives and depth of understanding of polyester waste management issues. The FGD aimed to assess the recyclability of each waste type and to estimate the distribution of waste flows into six end-of-life pathways (remanufacturing, closed-loop recycling, open-loop recycling, repurposing, incineration, and landfill). The resulting projections were used to calculate the volumes of the identified PIPW directed to each route.

This study was granted ethical approval by the Ethics Committee for Research Involving Human Subjects at IPB University. Prior to the commencement of data collection, the IPB School of Business issued formal letters of endorsement to the relevant institutions to secure research permissions at each designated study site. The objectives and scope of the study were clearly communicated to all key informants before data collection commenced. Informed consent was obtained in writing, thereby affirming the participants’ voluntary participation and ensuring anonymity and confidentiality of their identities and data. The interview and FGD protocols were developed in accordance with the MFA framework and the research objectives, and are provided as Supplementary Materials.

4.3. Procedure Analysis

4.3.1. Estimating Waste Mass, Waste Ratio, and Material Efficiency

Figure 4 illustrates the MFA framework employed in this study, which was validated through key informant consultations, as detailed in Section 4.2.2. The model encompasses inflows (I), outflows (O), and stock (S) at each stage of the production chain, from polymerisation through to garment assembly, within a multi-stage production system. In this context, inflow refers to the quantity of raw materials entering the production chain; outflow refers to the quantity of final products produced by each production process; and stock denotes the quantity of waste generated. All material flows are quantified in kilotonnes (kt).

The system boundary diagram depicts the textile production system at the sub-process level, explicitly illustrating material pathways and points of PIPW generation. For quantitative MFA and mass balance, these sub-processes are aggregated into five main production stages, as visualised in the Sankey diagram (Figure 1), developed using the web-based SankeyMATIC tool (Steve Bogart, Santa Cruz, CA, USA; https://sankeymatic.com/, accessed on 13 March 2025). In line with a resource-oriented interpretation of circularity, this study not only quantifies waste volume but also incorporates relative resource-efficiency indicators. Waste ratios and material efficiency are used to normalise waste generation relative to material inputs at each production stage and sub-process. These combined indicators enable the assessment of how effectively primary resources are converted into qualified products, thereby distinguishing structural inefficiencies from scale-driven waste generation.

• Waste generation

The Indonesian T&C industry sources raw materials from both domestic production and imports. Accordingly, the total inflow of raw materials at stage i (I_i) was defined as the sum of domestic output from the previous stage (d_i−1) and imports (m_i), minus exports of the prior stage (e_i−1), as expressed in Equation (1):

$$\sum _{i=0}^n{I}_i=\sum d_{i-1}+\sum m_i-\sum e_{i-1}$$

(1)

For production stages requiring multiple material inputs (e.g., PTA and MEG in polyester polymerisation), the total input (C_i) was calculated as the sum of all material flows (S_ij) entering the stage (Equation (2)):

$$C_i=\sum _{j=1}^k{S}_{ij}$$

(2)

Similarly, when a stage produced multiple output products, total domestic output (d_i) was calculated as the sum of all product outputs (O_ij), formulated as:

$$d_i=\sum _{j=1}^k{O}_{ij}$$

(3)

where O_ij represents the output of product type j from stage i (outflow), j is the product type, and k is the total number of product types.

The calculation of waste generation or stock (S) at each stage is the difference between input (I) and output (O), following the principle of mass balance:

$$\mathrm{S}=\mathrm{I}-\mathrm{O}$$

(4)

2.

Waste ratio and material efficiency

The waste ratio (R) quantified material losses relative to total resource input, while material efficiency (E) represented the proportion of raw materials successfully converted into qualified products. These indicators were calculated as:

$$\mathrm{R}={\displaystyle \frac{w}{I}}\times 100\mathrm{\%}$$

(5)

where: R is the waste ratio (%); w is the quantity of waste generated (kt); I is the total inflow (kt).

$$\mathrm{E}={\displaystyle \frac{d}{I}}\times 100\mathrm{\%}$$

(6)

where E is material efficiency (%), I is the total inflow (kt), and d is the total production output (kt). Together, these indicators provide a complementary, resource-based assessment of circularity performance across production stages with differing throughput levels.

4.3.2. Waste Typology

• Waste Characteristics

An understanding of waste characteristics constitutes a foundational step in developing a robust typology of PIPW. This stage involves examining waste-generation mechanisms throughout the T&C production process and identifying the physical and chemical characteristics of waste streams generated at each manufacturing stage. Nine semi-structured interviews were conducted both online and on-site, as detailed in Supplementary Material S7. The interviews addressed five principal themes: (i) T&C production processes, (ii) types of waste generated at each production stage, (iii) physical and chemical properties of waste, (iv) current waste management practices, and (v) recycling opportunities. The interview data were analysed using qualitative descriptive analysis, with the primary output identifying waste types and their characteristics, as presented in Table 3.

To estimate the composition of waste material, the study classified PIPW into pure polyester fibres, blended fibres, and polymeric or non-textile materials. Informants were asked to calculate the percentage distribution of each composition category for every waste type based on actual production practices, supported by internal company records and operational experience. These estimates were subsequently cross-validated through consultations with industry associations and academic experts to enhance data reliability.

Material composition volumes were quantified by combining informant-derived percentage estimates with waste volumes obtained from the MFA, as expressed in the equation:

$$M{C}_i=S_i\times P_i$$

(7)

where MC_i denotes the material volume (kt) of a given composition category associated with waste type i, S_i represents the total waste volume derived from the MFA (kt), and P_i is the estimated percentage share of the corresponding material composition category.

The resulting material volumes were then aggregated across all waste types and expressed as proportions of total PIPW. These system-level composition estimates provided the quantitative basis for the subsequent recyclability assessment and evaluation of feasible recovery pathways.

2.

Recyclability Assessment

Recyclability is defined in this study as a context-dependent and applied concept that reflects the relative suitability of a given PIPW stream for material recovery under prevailing industrial system conditions. Rather than representing a theoretical or technology-neutral property, recyclability is operationalised as the practical feasibility of recovery within the existing technological, economic, and institutional context of Indonesia’s T&C sector. Accordingly, the assessment captures the extent to which PIPW can be realistically processed and valorised through available recovery pathways, given material characteristics, market conditions, and current technological capabilities. This definition establishes the analytical boundary of the recyclability assessment and underpins the development of the waste typology and EoL pathway mapping employed in this study.

The recyclability assessment was conducted using a multi-criteria, expert-based approach to develop a structured waste typology informed by technical, economic, and technological considerations. The assessment was conducted via an online FGD on Zoom, involving nine experts from T&C manufacturing companies, recycling firms, and academia. Before scoring, a preliminary discussion was held to validate the recyclability criteria and ensure a shared understanding of the assessment scope and boundaries. Each expert then independently submitted initial scores via a Google Form; all individual scores were subsequently compiled and presented as the basis for facilitated deliberation. This procedure follows a modified Delphi approach, in which structured discussion is used to align expert judgements while preserving independent initial assessments [84].

During the session, participants were invited to explain the technical rationale underlying their scores. If score discrepancies exceeding two points were to occur between participants, these differences would be discussed openly during the plenary session to seek agreement. If, following the discussion, more than 30% of participants did not agree with the proposed score, the final value would be determined as the arithmetic mean of all individual scores, in accordance with the predefined protocol, with the level of consensus explicitly documented for transparency [85]. The final scores were subsequently used to construct the waste typology and to support the proportional allocation of each waste category across six EoL pathways.

The assessment integrates three equally weighted dimensions: material purity (MP), economic feasibility (EF), and technological availability (TA). Each waste type was evaluated using parameters adapted from prior studies [30,31,32]. Material purity reflects material homogeneity, contamination levels, and thermal or chemical degradation that affect polymer integrity [30]. Economic feasibility considers residual material value, handling and processing costs, and market demand for recycled outputs [86]. Technological availability evaluates the availability, compatibility, and adoption level of relevant recycling technologies within the Indonesian context, reflecting existing industrial capacity and infrastructure constraints [86,87].

Each dimension was scored on an ordinal scale from 1 to 5, where 1 denotes highly favourable recyclability conditions, and 5 denotes highly challenging conditions. The cumulative score across the three dimensions was used to classify waste types into five recyclability priority levels: high (3–5), high–moderate (6–7), moderate (8–9), moderate–low (10–11), and low (>12), as presented in

Table 7. Recyclability scoring criteria.

Dimension	Score
	1	2	3	4	5
MP	Single fibre, clean & untreated, intact & stable	Minor coating or additive, slight, removable traces, slightly oxidised	Partial blends, moderate contamination, minor degradation	Multi-fibre, heavy finishing, poor meltability	Complex & unrecoverable, crosslinked/hazardous, burnt or degraded
EF	High resale demand, low cost, established network	Moderate, steady demand, basic cleaning or shredding, some regular buyers	Limited market, moderate pre-treatment, and few regional buyers	Niche/inconsistent, multi-step & costly, rare/irregular buyers	No value, high cost; unfeasible. No available buyer
TA	Widely used, fully compatible, broadly adopted	Available but limited, minor adjustments, and some adoption	Pilot/demo stage, needs setup/support, a few adopters	Experimental/import only, low yield, uneconomical	Not available, incompatible, not adopted

. This classification provides a consistent and transparent basis for linking waste characteristics with feasible recovery pathways under current system conditions.

4.3.3. Pathways Mapping (Scenario A)

The objective of the recovery pathway mapping is to estimate the circularity potential of identified PIPW by allocating the respective volumes of each waste type across six EoL pathways: remanufacturing, repurposing, closed-loop recycling, open-loop recycling, incineration, and landfilling. The initial volume of each waste type was derived from the MFA results described in the preceding section. Accordingly, Scenario A is conceptualised as a feasible optimisation benchmark grounded in existing recovery practices and currently available infrastructure, rather than a direct representation of the statistical status quo of polyester waste management in Indonesia.

In this study, the selected EoL pathways were defined based on their position within the value-retention hierarchy and their operational relevance to the Indonesian textile industry [86]. Remanufacturing refers to the reworking or reprocessing of textile products or semi-finished materials, such as fibre, yarn, or fabric residues, into functional textile outputs with the same intended use, without material transformation or depolymerisation, thereby preserving material integrity and product form [88,89]. This pathway was applied only to selected waste streams that retain sufficient physical structure, relative homogeneity, and low levels of contamination. By contrast, repurposing is defined as the utilisation of waste materials to produce new products with different functions, without material transformation or depolymerisation [88]. This route was applied to waste streams that maintained adequate physical integrity but were typically heterogeneous in colour, composition, or geometry, and exhibited moderate levels of contamination.

In this study, mechanical recycling was not treated as a distinct EoL pathway, as it represents a processing method rather than an EoL outcome. Moreover, in the Indonesian context, mechanical recycling is predominantly associated with open-loop recycling routes, which downcycle polyester into lower-grade products with reduced functional and economic value [33,34]. In contrast, closed-loop recycling refers to processes that regenerate polyester feedstock suitable for reintegration into textile production, which require high levels of material purity and homogeneity [9,19,33]. Incineration and landfilling were treated as terminal pathways, reflecting technical, economic, and material-quality constraints within the current system. They were applied only to waste streams that could not be feasibly recovered through higher-value circular routes [9].

The allocation of waste flows to each EoL pathway was quantified based on expert judgement. During the FGD, experts were asked to estimate the percentage of each waste type that could plausibly be directed to each EoL route. These estimates were developed systematically by considering three principal factors: waste typology, the availability of recycling technologies and supporting infrastructure currently operating in Indonesia, and practitioners’ experiential knowledge of textile waste management. The discussion was structured and moderated to achieve consensus on the proposed allocation proportions. These proportions were subsequently multiplied by the actual waste volumes obtained from the MFA to generate quantitative estimates of waste flows into each recovery pathway, expressed in kilotonnes, using the following equation:

$$V_{ij}=T_i\times P_{ij}$$

(8)

where $V_{ij}$ denotes the mass of waste type i flowing into pathway j (kt), $T_i$ represents the total volume of waste type i as identified by the MFA (kt), and $P_{ij}$ indicates the percentage allocation of waste type i to pathway j (%). The recovery pathway mapping developed under Scenario A subsequently serves as the quantitative basis for the waste reallocation analysis conducted under Scenario B.

4.3.4. Redirection Potential to Chemical Recycling (Scenario B)

Scenario B was developed to explore the potential to enhance the material value of PIPW by selectively reallocating waste streams from lower-value recovery pathways identified in Scenario A to chemical recycling. The primary objective of this scenario is to estimate the volume of PIPW that is technically and economically feasible to redirect to chemical recycling, while maintaining supply stability in recovery pathways that are already operational and well established in downstream sectors. In this study, chemical recycling is treated as a valorisation pathway capable of processing waste types that are unsuitable for remanufacturing or closed-loop recycling due to physical heterogeneity, fibre blends, or specific levels of contamination. Accordingly, Scenario B is not intended as a projection or prediction of future waste management conditions, but rather as a feasibility-based exploratory scenario designed to assess the magnitude of feedstock potential that could support the development of chemical recycling under current and emerging technological conditions.

The feasibility of reallocating waste to chemical recycling was evaluated based on four main criteria: (1) waste typology; (2) the potential for value enhancement through conversion into high-quality secondary raw materials suitable for T2T applications; (3) the technical feasibility of chemical recycling based on the compatibility of each waste type with polyester chemical recycling routes such as glycolysis-based depolymerisation, methanolysis, or selective solvent-based routes [9,19,34]; and (4) system stability considerations, particularly the potential disruption to waste supply for existing recovery pathways if reallocation were to be implemented [21,67].

The determination of reallocation proportions employed a mixed-methods approach, combining a synthesis of the literature with an in-depth assessment of the waste typologies identified through the MFA and field observations. To strengthen methodological robustness, the assessment outcomes were validated through a semi-structured interview with an academic expert specialising in textile recycling technologies. This validation aimed to ensure that reallocation decisions were aligned with realistic technical constraints and with industrial practices relevant to the Indonesian context.

The volume of waste reallocated to chemical recycling was calculated using the following equation:

$${R_{ij}=V_i\times P}_{ij}$$

(9)

where: $R_{ij}$ is the mass of waste from pathway i redirected to chemical recycling (kt); $V_i$ is the total volume of waste in pathway i under Scenario A (kt); and $P_{ij}$ is the projected percentage of waste in pathway i that can be feasibly allocated to chemical recycling (%)

The total reallocation potential, representing the feedstock gap for chemical recycling, was then calculated by summing all reallocated waste volumes from lower-value recovery pathways as follows:

$$G=\sum _{j=1}^k{R}_{ij}$$

(10)

where $G$ is the total feedstock potential suitable for chemical recycling (kt), and $k$ represents the number of lower-value recovery pathways considered.

In this scenario, only waste streams flowing to open-loop recycling, repurposing, incineration, and landfilling were considered for reallocation. In contrast, flows assigned to remanufacturing and closed-loop recycling were preserved to comply with value-retention principles.

5. Conclusions

This study provides the first national-level MFA of PPIW within Indonesia’s polyester T&C manufacturing system. By integrating national industrial statistics, trade data, site visits, and expert-based recyclability assessment, the study quantifies the volume, composition, and T2T recycling potential of PIPW in 2023.

The findings indicate that approximately 572 kilotonnes of PIPW were generated in 2023, with garment manufacturing contributing the largest share. The predominance of blended fibres significantly constrains the feasibility of closed-loop T2T recycling under current industrial conditions. Beyond quantification, this study develops a structured five-tier waste typology that integrates material properties, economic feasibility, and technological availability to classify nineteen distinct waste streams according to their recyclability potential. This typology provides a systematic basis for linking fibre-specific waste characteristics to feasible end-of-life pathways within the Indonesian context.

The circularity mapping under Scenario A reveals that most PIPW is channelled into open-loop recycling and repurposing routes, while only a limited fraction re-enters closed-loop textile production. This configuration suggests a condition of pseudo-circularity, in which waste diversion does not necessarily convert into material value retention within the polyester textile system.

The exploratory Scenario B analysis indicates that up to 184 kilotonnes of PIPW could potentially be redirected towards chemical recycling, provided that improvements in source-level segregation, feedstock quality control, and supporting infrastructure are achieved. However, this potential is conditional upon technological readiness, economic viability, and institutional coordination within Indonesia’s industrial context.

These findings suggest that advancing textile circularity in Indonesia requires not merely increasing recycling rates but addressing structural mismatches between waste characteristics, recovery technologies, and governance arrangements. The evidence presented in this study establishes an empirical baseline for national policy design and industrial planning. While the analytical framework may be adaptable to other textile-producing economies, the quantitative results and scenario implications are specific to Indonesia’s polyester-based T&C system in 2023.