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Removal of spandex from nylon/spandex blended fabrics by selective polymer degradation
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As the use of fabrics containing spandex for apparel applications is expanding, developing eco-friendly technologies to recycle the industrial as well as post-consumer waste for spandex blended fabrics becomes increasingly important. As is known in the industry and demonstrated in this study, spandex may be removed from blended fabrics by dissolving it in solvents such as N,N-dimethylformamide, but the use of such solvents is undesirable for economical and environmental reasons. The main focus of this study was to develop an alternative process for removing the spandex component in a nylon/spandex blended fabric (NSBF) by selective degradation so that the nylon component can be recovered for recycling. In this process, the fabric first underwent a heat treatment step, followed by a washing process. For the heat treatment, the effect of temperature, water-to-fabric ratio, and pressure were studied. Treatment at 220? for 2 hours under atmospheric pressure was found to be very effective, allowing the degraded spandex residues to be readily washed off in ethanol, while the nylon component retained its original morphology. With the removal of spandex in NSBF, a decrease in -CON- absorption peaks in the Fourier transform infrared-attenuated total reflectance spectra of the fabrics was observed.
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... Currently, most of the clothes containing elastane are not recycled because it is difficult to separate synthetic polymers from blends. Yin et al. (2014) developed a method for the selective separation of synthetic polymers from their blends and the recovery of the main polymer [86]. The separation of elastane from elastane/nylon blend clothes was made by a washing process at 220 • C using ethanol and water. ...
... Currently, most of the clothes containing elastane are not recycled because it is difficult to separate synthetic polymers from blends. Yin et al. (2014) developed a method for the selective separation of synthetic polymers from their blends and the recovery of the main polymer [86]. The separation of elastane from elastane/nylon blend clothes was made by a washing process at 220 • C using ethanol and water. ...
Trends in the textile industry show a continuous increase in the production and sale of textile materials, which in turn generates a huge amount of discarded clothing every year. This has a negative impact on the environment, on one side, by consuming resources—some of them non-renewables (to produce synthetic polymers)—and on the other side, by polluting the environment through the emission of GHGs (greenhouse gases), the generation of microplastics, and the release of toxic chemicals in the environment (dyes, chemical reagents, etc.). When natural polymers (e.g., cellulose, protein fibers) are used for the manufacturing of clothes, the negative impact is transferred to soil pollution (e.g., by using pesticides, fertilizers). In addition, for the manufacture of clothes from natural fibers, large amounts of water are consumed for irrigation. According to the European Environment Agency (EEA), the consumption of clothing is expected to increase by 63%, from 62 million tonnes in 2019 to 102 million tonnes in 2030. The current article aims to review the latest technologies that are suitable for better disposal of large quantities of textile waste.
... Currently, most of the clothes containing elastane are not recycled because it is difficult to separate synthetic polymers from blends. Yin et al. (2014) developed a method for the selective separation of synthetic polymers from their blends and the recovery of the main polymer [86]. The separation of elastane from elastane/nylon blend clothes was made by a washing process at 220 • C using ethanol and water. ...
... Currently, most of the clothes containing elastane are not recycled because it is difficult to separate synthetic polymers from blends. Yin et al. (2014) developed a method for the selective separation of synthetic polymers from their blends and the recovery of the main polymer [86]. The separation of elastane from elastane/nylon blend clothes was made by a washing process at 220 • C using ethanol and water. ...
This paper reviews the advantages and disadvantages of the use of fertilizers obtained from leather waste, to ameliorate the agricultural soil quality. The use of leather waste (hides and skins) as raw materials to obtain biopolymer-based fertilizers is an excellent example of a circular economy. This allows the recovery of a large quantity of the tanning agent in the case of tanned wastes, as well as the valorization of significant quantities of waste that would be otherwise disposed of by landfilling. The composition of organic biopolymers obtained from leather waste is a rich source of macronutrients (nitrogen, calcium, magnesium, sodium, potassium), and micronutrients (boron, chloride, copper, iron, manganese, molybdenum, nickel and zinc), necessary to improve the composition of agricultural soils, and to remediate the degraded soils. This enhances plant growth ensuring better crops. The nutrient release tests have demonstrated that, by using the biofertilizers with collagen or with collagen cross-linked with synthetic polymers, the nutrient release can be controlled and slowed. In this case, the loss of nutrients by leaching into the inferior layers of the soil and ground water is minimized, avoiding groundwater contamination, especially with nitrate.
... Elastane is sensitive to high temperatures. A study by Yin suggests separating PA and elastane in blended fabrics for recycling by heating the material, which damages the elastane but not the PA [13]. All these studies confirm that ageing degrades PA, PES and elastane at the molecular level, but ageing also changes the properties of the textiles. ...
... Polymers 2021,13, 2414 ...
The degradation of polyamide (PA) and polyester (PES) polymers is under intense study due to growing concerns about the accumulation of plastics in soils and oceans. Previous studies confirm that ageing degrades PA and PES at the molecular level. However, researchers have not addressed the development of protocols for aging textile materials in swimming pools, and few data are available on the effects of aging on comfort and durability. This research addresses the development of the aging protocol for PA and PES swimwear materials, its implementation, and the evaluation of properties that assure comfort and durability after specific periods of exposure. The tests include microscopic analysis, tensile tests, determination of fluid transport phases and drying period. The results revealed changes in the surface of the material in terms of fibrillation (more pronounced after outdoor aging). There is a positive correlation between the exposure duration and the breaking force (R2 ranges from 0.85 to 0.98), with a stronger correlation for the PA materials. The decrease in breaking force due to aging is up to 40%, indicating significantly reduced durability. The change in breaking force follows the changes in mass (R2 = 0.867). In terms of comfort assurance, outdoor aging of materials should have a greater negative impact than indoor ageing.
... Though bamboo is also composed of cellulose, the bamboo utilised in this study was 95% viscose based and therefore technically synthetic in nature (i.e., chemically treated) using regenerated cellulose (structurally the same as natural cellulose; Kauffman, 1993) and 5% elastane, which is a synthetic polymer. Elastane is known for its extreme exibility and hence a useful addition to clothing, but it is also recognised as non-recyclable and not easily degraded in natura (Yin et al., 2014). For this study bamboo exposure and consumption was associated with signi cantly lower peak pathogen burdens compared with sh not exposed to any bres, while also reaching these peaks much later than the control treatments. ...
Plastic pollution is now a ubiquitous feature of freshwater systems and the majority of this is fibrous. Here, we test the effects of plastic and cellulose-based fibres (polyester, cotton, and bamboo from commercial clothing) on fish host-parasite interactions using a freshwater fish host-parasite model system (Guppy Poecilia reticulata - Gyrodactylus turnbulli ). For uninfected fish, polyester exposure was associated with significantly higher mortality rates compared with the other two fibre types. For infected fish, while polyester and cotton exposure were not associated with any significant changes to parasite burdens, fish exposed to bamboo fibres had significantly reduced maximum parasite burdens compared with fish not exposed to any fibres, indicating that the bamboo fibres and/or associated dyes conferred some degree of resistance. While unable to determine the exact nature of the chemical dyes, when testing off-host parasite survival on exposure to the fibre dyes, cotton and particularly polyester dyes were associated with higher parasite mortality compared to bamboo. Overall, we add to the growing body of evidence which shows that fibrous microplastics and associated dyes can be detrimental for fish health, and we highlight the need for increased transparency from textile industries on the chemical identity of fabric dyes.
... Elastane (EL) fibres are per definition comprised of at least 85% of mass of a segmented polyurethane that can stretch up multiple times (100-600%) its normal length and immediately reverts into origin shape when the applied force is removed [17][18][19]. In North America and Europe, EL is frequently called spandex or by its prominent brand name LYCRA®. ...
Elastane, also known as spandex, is a synthetic polymer fibre based on polyurethane, which is present in low amounts in numerous textile products. It is used frequently particularly in sportswear and underwear, because of its stretchability and body-shaping properties. The currently commonly-used standardized elastane quantification method has many outstanding disadvantages, however ongoing production processes as well as upcoming recycling processes rely on it. This study presents a faster, more reliable and more eco-friendly tool to detect and quantify elastane in textiles using differential scanning calorimetry (DSC). An elastane quantification tool (EQT) was developed by studying eleven different elastane samples available on the textile market. The fundament of the EQT is a polymer specific phenomenon, which is investigated in detail by spectroscopic (ATR-FTIR) and thermal (thermogravimetric analysis, DSC) analyses. Ten different textile waste samples from the manufacturing industry and waste collection were selected to test the EQT. Obtained results are very promising, as the elastane contents could be determined quickly and accurately. The EQT has the potential to become a widely used method in the textile production chain, particularly in the upcoming recycling sector.
... Pre-consumer textile waste consists of synthetic material such as Nylon/Spandex (NS) which are being used to produce both intimate and activewear that is problematic to recycle (Dissanayake et al., 2018). There are limited recycling technologies available for recycling NS blended fabric and single polymer nylon could be recycled (Yin, Yao, Wang, & Wang, 2014). In Sri Lanka, 25% of textile waste is reuse or recycling while 80,000 to 19,000 tonnes are annually incinerated (Jayasinghe et al., 2010). ...
The investigation focused on the separation, through selective dissolution, of polyamide 66 (PA 66) from mixtures with cellulose fibers with calcium chloride‐ethanol‐water (CEW). The dissolved PA 66 was reprecipitated by addition of water. Analysis of the cellulose after separation revealed no change in mechanical strength, suggesting the polymer was undamaged by the treatment. There were residues of the polyamide retained on the cellulose, but a substantial proportion could be removed by carding. About 80–90% of the PA 66 originally present in the mixtures was recovered. Effective removal of calcium residues from the recovered PA 66 is found to be critical, as calcium contents of greater than ca. 0.8 wt% in the polymer is observed to change the melt behavior. These investigations are being conducted in the broad context of fiber‐to‐fiber recycling from textiles, and will be followed up by investigations on the impact and fate of colorants present in the fibers.
This article intends to shift current discourse on material thinking and agency from thinking of and through materials to thinking with materials; we therefore argue that re-locating the affects and agency of costume materiality in the changing material environment at this current moment is essential. Responding to the global environmental crisis and based on the emergent philosophical concepts of extramaterialism and costume thinking, examined through the prism of ecosomatics, we propose a critical approach to think and (co)create in contemporary costume praxis informed by ecological sensibility. Through acknowledging that the material, the natural and the cultural are not separate but co-constitutive, our aim is to provoke new insights into more-than-human material agency. This is explored by addressing the relationship between living and non-living things and the systems created through the inter- and intra-actions between these elements via the medium of costume. By analysing the use of biobased materials as costume matter in two case study productions, the article positions costume design as a critical tool for new performance narratives and cultural landscapes to be considered and created. It pushes the boundaries of wider philosophical understandings and innovations in costume with the potential to influence broader, environmentally aware cultural and societal contexts.
The fashion industry contributes to a significant environmental issue due to the increasing production and needs of the industry. The proactive efforts toward developing a more sustainable process via textile recycling has become the preferable solution. This urgent and important need to develop cheap and efficient recycling methods for textile waste has led to the research community’s development of various recycling methods. The textile waste recycling process can be categorized into chemical and mechanical recycling methods. This paper provides an overview of the state of the art regarding different types of textile recycling technologies along with their current challenges and limitations. The critical parameters determining recycling performance are summarized and discussed and focus on the current challenges in mechanical and chemical recycling (pyrolysis, enzymatic hydrolysis, hydrothermal, ammonolysis, and glycolysis). Textile waste has been demonstrated to be re-spun into yarn (re-woven or knitted) by spinning carded yarn and mixed shoddy through mechanical recycling. On the other hand, it is difficult to recycle some textiles by means of enzymatic hydrolysis; high product yield has been shown under mild temperatures. Furthermore, the emergence of existing technology such as the internet of things (IoT) being implemented to enable efficient textile waste sorting and identification is also discussed. Moreover, we provide an outlook as to upcoming technological developments that will contribute to facilitating the circular economy, allowing for a more sustainable textile recycling process.
This paper focuses on the dimensional and selected physical properties of a series of plain jersey fabrics made from viscose siro-spun and carded ring yarns of 2/10 tex and 20 tex, respectively. Elastane yarn was incorporated into the fabric using the plaiting technique. In general, for both greige and dyed knitted fabrics, the stitch density decreased, whereas the weight increased as the stitch length increased. Moreover, for greige and dyed dry-relaxed fabrics from siro yarn, the twist had an infuence on fabric properties, the effect being relatively more prominent for slack samples. Moreover, both slack and tight dry relaxed dyed samples from high twist siro yarns featured lower resistance to abrasion. As far, as dyed and laundered samples from siro yarns are concerned, the results revealed that irrespective of the loop length, the samples from average twist siro yarns tended to give a higher stitch density and weight values. When abrasion resistance values of samples from both average and high twist siro yarns were studied, it could be suggested that in addition to yarn properties, the effect of fabric properties on the abrasion behaviour of the samples became more prominent after laundering. As far as the abrasion resistance and pilling properties of the samples are concerned, the fabrics from siro-spun yarns tended to perform better. Finally, the pilling test method employed affected not only the size and shape of the pill entanglements on the surface of the samples but also the degree of fbre damage within the fuzz entanglements.
Nowadays the application of elastic core-spun yarns in fabric manufacturing and the clothing industry has increased tremendously. These yarns undergo tensile fatigue loading, a common phenomenon which occurs on some part of apparel such as the knee during wearing and use. In this research, cotton covered spandex filament core-spun yarns with 5 different draw ratios on the core part were subjected to 500, 1000 and 1500 tensile fatigue cyclic loads using a purpose-built instrument for fatigue behavior assessment. Also, the woven fabrics of these yarns were produced and underwent the same cyclic loadings. Tensile properties of fatigued yarns were measured by a tensile tester. The yarn deformation and displacement of core and sheath parts was traced via a microtomy technique and scanning electron microscopy (SEM) studies. Finally, the surface of the fatigued fabrics was studied by image processing to see any surface roughness and pilling due to straining. The results revealed the pronounced effect of draw ratio on the breaking strength and breaking elongation after cyclic loading. The obtained results showed that the samples produced by a 2.9 and 3.9 draw ratio of the core part had the highest and lowest level of breaking strength after 1500 tensile cyclic loading, respectively. The samples produced by a 2.9 draw ratio showed the highest decrease of breaking elongation after 1500 tensile cyclic loading. The likely mechanism of buckling behavior of core-spun yarns after experiencing strain energy is proposed. The results showed that after 1000 cyclic loads, the highest number of pills was countable on the fabric surface.
This article presents a new process for the selective separation and recovery of nylon material from carpet waste using a solvent-based selective dissolution technique combined with supercritical fluid antisolvent precipitation. The process is described in three primary stages: (1) selective dissolution of nylon up to 2.31 wt.% from the model carpet with an 88 wt.% liquid formic acid solution is performed at 40°C, (2) recovery of the nylon product powder with supercritical C02 antisolvent precipitation at pressures between 84 and 125 bar at 40°C, and (3) recycle of both the solvent and antisolvent by flashing into two phases. Detailed studies on the supercritical fluid antisolvent precipitation (stage 2) of the nylon material from carpet waste were performed in which the influences of operating conditions were examined. Effective recovery of the nylon material was achieved with control over the morphology and particle size of the nylon powder. The particles obtained were typically less than 20 μm and spherical in nature, with exceptions observed at the highest operating pressure above 300 bar. In general, the experiments illustrate that changes in operating pressures (both upstream and down-stream of the expansion nozzle), nozzle diameter, and solution concentrations had little influence on the particles' mean size and size distribution. The results suggest this process to be very controllable. In addition, analysis of the nylon product illustrated that this process shows promise in providing quality nylon material from waste carpet material.
In this study, the effects of spandex brand, the tightness factor of the base, and spandex yarn on the dimensional and physical properties of cotton/spandex single jersey fabrics are investigated. In order to examine the effects of the tightness factor of cotton and spandex yarn, fabric samples were knitted by feeding both cotton and spandex yarns with three different adjustments of positive yarn feeding mechanisms so as to produce tight, medium, and loose cotton/spandex single jersey fabrics. Four different spandex yarns were used. The fabrics knitted with spandex yarns that have the largest tension values under a constant draw ratio give the highest weight, courses/cm, stitches/cm, thickness, and lowest air permeability values. Spandex yarns that have similar elongation % values affect the wale per cm values in a similar way. Because of the greater stretched structure of the spandex yarns that have shorter loop length values, the width of the fabric decreases and then the thickness of the fabric increases.
A family of synthetic elastic fibers, designated spandex fibers, has been developed, providing new degrees of sheerness and
effective "power" in elastic fabrics. These fibers have segmented polyurethane structures. They are durable, they are white
and accept dye readily, and they can be set by heat. The development of these fibers has led to new textile technology and
to new uses for elastic fabrics.
In this article, the draw ratio of elastic core yarn (Spandex filament 44 dtex/f4) was regulated from 2.7 to 4.41 (i.e., 2.7, 3.22, 3.49, and 4.41) by using a developed positive feed drive and a microcontroller system. The elastic core positioning (left, center, and right) in front roller nip of ring frame was also changed using a standard V-groove guide roller. The physical properties of produced yarns including tensile properties, hairiness, irregularity, and fibre covering were investigated and compared. The results revealed that at 3.49 draw ratio, themaximum elastic core-spun yarn tenacity and elongation and minimum S3 hairiness values were obtained compared with 2.7 and 4.41 draw ratios. The results indicated that increasing the elastic yarn draw ratio increased the elastic core-spun yarn irregularity and fibre-covering factor by which the highest values were obtained at 4.41 elastic yarn draw ratio. It was also found that elastic yarn positioning at the left edge of roving ribbon deteriorated core-spun yarn evenness while elastic yarn positioning at the center of the roving ribbon improved the core-spun yarn hairiness. However, elastic yarn positioning has no significant effect on elastic core-spun yarn tensile and fibre-covering properties.
The rheological behavior of polyurethane (PU)/N,N-dimethylformamide (DMF) spinning solutions with various contents of hyperbranched polyesters was studied using a RS150L-controlled stress rotational rheometer. The results showed that the viscosity of the spinning solutions could be greatly reduced by adding hyperbranched polyesters even at 0.5 wt% loading. The zero-shear viscosity of solutions with hyperbranched polyesters was much lower than that of pure PU/DMF solution, which indicated a lower degree of entanglement when solutions were in a static state. The apparent activation energy of viscous flow and the critical shear rate for shear thinning of solutions with hyperbranched polyesters were much lower than that for pure PU/DMF solution, which indicated a weaker entanglement structure formed. In addition, the effect of hyperbranched polyesters on the mechanical properties of Spandex fiber was discussed. Copyright © 2006 Society of Chemical Industry
The internal structure and orientation behavior of two series of spandex fibers, which were made with different spinning methods and different soft and hard segment types, were studied by FTIR (Fourier Transform Infrared Spectroscopy), polarizing light microscopy, and Instron. The orientation behavior of hard and soft segments was studied with FTIR and those of polymeric chains with polarizing miscroscopy while the fibers were being stretched by the mechanical stretcher. The orientation behavior of dry-spun fibers was observed to be very different from that of the melt-spun fibers, which may be explained in terms of the internal structural difference such as the degree of phase separation and mechanical stability of the hard domains between the two types of fibers. In general, the dry-spun fibers showed better elastic recovery property than the melt-spun fibers. Since the polymer for the dry-spun fibers was synthesized with ethylene diamine as a chain extender resulting in the urea groups in the hard segments, it forms more stable hard domain due to the high cohesion energy between the urea groups. The change of the birefringence values during the cyclic deformation was studied with the polarizing light microscopy. The birefringence behaviors of the two dry-spun fibers were similar, whereas there was a noticeable difference between the two melt-spun fibers. The difference was explained in terms of the effect of crosslinking agent in one of the melt-spun fibers, which can stabilize the hard domain structure against the external stress. Mechanical hysteresis values measured gave results consistent with those of FTIR and birefringence measurements. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 1821–1832, 1997
The effect of the multiple recycling of nylon-6 by injection molding on its physical–mechanical properties and morphology was studied after each cycle of injection. These studies were made in order to know how many times it is possible to recycle the nylon-6 without significant loss of the physical–mechanical properties. Optical and electronic microscopy were used to evaluated the morphology. Molecular weight changes were determinated by gel permeation chromatography (GPC). The nylon-6 was recycled 10 times, until the eighth cycle the properties of the material did not suffered any change. Changes of 10–15% in the properties between nylon-6 with 10 cycles of injection and virgin material were observed. An exception was the percentage of elongation that decreased 70% gradually until in the tenth cycle of injection. The results from GPC show that the molecular weight of nylon-6 increased with recycling (Mw = 17% and Mn = 14%). With the reprocess was also observed the presence of gels. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 851–858, 2000
Spandex fibers were obtained by melt spinning segmented copolyetheresteramides with crystallizable aromatic diamide units of uniform length and poly(tetramethyleneoxide) segments. The aramid content was varied from 3 to 22 wt %, and the molecular weight of the polyether segment ranged from 1000 to 9000 g/mol. The influence of the spinning and drawing conditions on the fiber properties was investigated. The aromatic diamide units crystallize very fast. This made the melt spinning of the polymers easy. The aramide units were also found to be very effective in increasing the modulus. For a high elasticity a low aramid content was beneficial, and with a few percent a good elastic behavior is obtained. Orientation by drawing or a spin drawing process improves the elastic behavior. The elastic properties are compared to the values of commercial spandex fibers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2194–2203, 2001