Fiberfill: Fiberfill consists of continuous polyester filaments, but these filaments are produced specifically to have the most possible volume to make bulky products like pillows, outerwear, and stuffing for stuffed animals.
The process of creating polyester fiber begins with reacting ethylene glycol with dimethyl terephthalate at high heat. This reaction results in a monomer, which is then reacted with dimethyl terephthalate again to create a polymer. This molten polyester polymer is extruded from the reaction chamber in long strips, and these strips are allowed to cool and dry, and then they are broken apart in to small pieces.
The resulting chips are then melted again to create a honey-like substance, which is extruded through a spinneret to create fibers. Depending on whether filaments, staple, tow, or fiberfill fibers are desired, the resulting polyester filaments may be cut or reacted with various chemicals to achieve the correct end result.
In most applications, polyester fibers are spun into yarn before they are dyed or subjected to other post-production processes. The process of creating PCDT polyester is similar to the process of creating PET polyester, but this polyester variant has a different chemical structure.
While PCDT also consists of ethylene glycol reacted with dimethyl terephthalate, different production processes are used to make these two common polyester variations. Most types of plant-based polyester are also made from ethylene glycol reacted with dimethyl terephthalate.
While the source of the ethylene used in PET and PCDT polyester is petroleum, however, producers of plant-based polyester use ethylene sources like cane sugar instead. For instance, this plastic is used to make food containers, water bottles, and a variety of other types of industrial and consumer products. In its fiber form as polyester fabric, however, PET is used in hundreds of different consumer applications. Traditionally, PET has been used as an alternative to cotton, and in some applications, it may also serve as a reasonable alternative to other natural fibers like wool and silk.
Essentially, anything made from cotton can also be made with polyester. From everyday shirts and pants to glamorous eveningwear, the apparel applications of polyester fabric are endless. Manufacturers use polyester fabric to make suits, jackets, socks, underwear, and pretty much anything that you can wear for casual, business, or formal occasions.
Additionally, manufacturers also use polyester to craft various homewares. In particular, a type of polyester called microfiber has gained prominence in the bath and kitchen homeware categories.
Consumers value the softness and absorbency of microfiber in applications like bath towels, face towels, and kitchen towels. Manufacturers may also use polyester to make homewares like blankets, rugs, upholstery, and curtains. Polyester fabric may be used as cushioning for chairs, sofas, and pillows, and due to the impressive stain-resistance of this material, many parents and pet owners prefer polyester products.
Industrial applications of polyester include LCD displays, holographic film, boats, tarps, and bottles. For example, a comparison of biobased TPA produced from corn, sugarcane and orange peel and TPA produced from oil [ 24 ] revealed that first-generation raw materials corn and sugarcane had a similar environmental impact to oil, mainly due to the depletion of resources and the extra land required for crop cultivation.
In contrast, the biobased route involving second-generation materials, specifically the upcycling of side-streams such as orange peel, achieved the most sustainable solution with the lowest environmental impact because it did not involve resource extraction or land use and made use of resources that would otherwise be wasted.
Key recommendations to improve the sustainability of polyester manufacturing at the raw material stage therefore include phasing out the use of fossil fuels as a material source for PET production and for the provision of energy. In theory, ester bonds can be hydrolyzed, which means PET can be de-polymerized, but the large aromatic ring gives PET notable stiffness and strength, especially when the polymer chains are arranged in an orderly manner as in the case of textile fibers, making PET highly resistant to biodegradation at its end-of-life phase [ 25 ].
The wastewater contains chemical residues, and appropriate disposal is therefore necessary. The smart management of resources and residues can help to improve this process, and the use of renewable energy is recommended where possible because the generation of high temperatures results in significant CO 2 emissions if fossil energy is used. In the final step, PET is compressed into pellets for sale.
These pellets are considered a subgroup of microplastics and cause detrimental effects in the environment if spilled during distribution [ 26 ]. PET pellets are melted, extruded and spun into filaments Fig. These filaments are then subjected to a thermal drawing process to improve mechanical properties such as tenacity.
During the drawing process, PET molecules are reoriented in the fiber direction and crystallize. The crystallinity of the fiber therefore depends on the applied draw ratio [ 27 ].
Drawn filaments are then combined and further processed in different ways to form yarns with specific characteristics [ 28 ]. There are many ways to combine filaments into yarns, depending on the final application of the textile.
Yarns can have a high twist which provides structural integrity , a low twist or no twist. They can be prepared from short staple fibers or longer infinite filaments. Similarly, yarns can be texturized at different levels to make them softer or more flexible, which can be achieved by the thermal or mechanical deformation of individual filaments.
The total amount of energy consumed during this step depends on the thickness of the yarn, because thinner yarn has a lower energy demand per kilogram [ 29 ].
Regardless of the yarn properties, renewable energy is recommended to reduce CO 2 emissions. Yarns are then knitted or weaved to produce fabric, which is confected into garments. This involves pattern-cutting mechanical or thermal and sewing. The smarter the pattern-cutting process, the less waste is generated.
A smart design process using software that minimizes the size of cut-out pieces and, if possible, recycles this waste back into the textile chain, is already widely used in the textile industry, and sets a good example of sustainable manufacturing [ 31 ]. Microfibers are released into the air during garment manufacturing and can stay there as airborne fibers [ 32 ].
Given the high aspect ratio and surface area of such fibers, compounds that bind to the surface can accumulate as environmental pollutants [ 34 ]. Microfibers are considered a subgroup of microplastics and can detach from textiles throughout their life cycle due to mechanical forces.
Factory workers come into contact with microfibers, synthetic dyes and petrochemicals on a daily basis through inhalation or skin contact, putting their health at risk and increasing the prevalence of respiratory disorders including asthma and interstitial lung disease and allergies [ 7 ].
Long-term exposure 10—20 years is also associated with a higher incidence of lung cancer [ 35 ]. This is analogous to asbestos, a mineral fiber that is banned in many countries [ 36 ] due to its harmful effect on the lungs, leading to a specific type of cancer known as mesothelioma [ 37 ].
Pigments and colorants can be applied to textiles at different production stages. They can be mixed with the melted polymer, or added to fibers, yarns, fabrics or garments using different techniques that vary in their environmental impact [ 11 ]. Here, textile products fibers, yarns, fabrics or garments are submerged in an aqueous solution containing dyes and chemicals such as dispersing agents and carriers.
Some of these chemicals may be hazardous [ 38 ] and the wastewater must be treated before disposal or reuse. Wastewater treatment is common practice in Europe, but other textile-producing countries pump wastewater directly into water bodies [ 29 ] causing environmental pollution through emissions to land and water, and thus direct harm to the ecosystem [ 39 ].
Furthermore, PET fibers are hydrophobic and highly crystalline, so thermal assistance is required during batch-dyeing so that pigments can penetrate the fiber [ 11 ].
This emits 2. A more recent method for the dyeing of synthetic fabrics or garments uses supercritical CO 2 as a solvent [ 40 ]. Non-polar dyes readily dissolve in supercritical CO 2 , avoiding the use of water or chemicals. Furthermore, this method can use CO 2 captured from industrial emissions and recycle it in a closed-loop system. However, high pressure is required to generate supercritical CO 2 — bar which increases energy consumption [ 40 ]. The energy costs and capital investment needed for supercritical CO 2 dyeing makes this method unappealing for many companies.
Only a few offer this technology, for example DyeCoo in the Netherlands. Another method is dope dyeing, in which pigments are extruded along with the melted polymer so that the resulting fibers are already colored. Because the fibers are colored at the beginning of the textile chain, a smart system should be implemented to extrude and spin only the necessary quantity of colored fibers, avoiding extra production waste. It is easier to produce non-colored fibers in bulk and dye them on demand later, so dope dyeing is not widely used in the industry.
Both synthetic and natural pigments are compatible with any of the dyeing processes outlined above. Synthetic dyes are used most widely because they are stable and inexpensive, but they persist in the environment [ 42 ], and some trigger allergic reactions [ 43 ] or even cause cancer [ 44 ]. Attention has therefore switched to natural dyes [ 45 ], such as curcumin [ 46 ] and alizarin [ 47 ], which are biodegradable and in some cases bioactive e.
However, natural dyes offer a limited range of colors and have a lower thermal stability, causing them to degrade more rapidly. They are also more difficult to produce in bulk, making them more suitable for small-scale production [ 11 ]. Nevertheless, genetic engineering and fermentation technologies have recently made it possible to obtain natural pigments on a larger scale thanks to dye-producing microorganisms.
Although these dyes are still not widely available, companies such as Colorifix UK and Pili France are currently optimizing and upscaling production, and the Dutch company Living Colors has recently collaborated with Puma to create a demonstrator collection using such dyes. More than 15, chemicals can be used during the textile manufacturing process, including detergents, flame retardants, stain repellents, softeners and carriers [ 49 ]. On average, the production of 1 kg of textiles consumes 0.
The residues of these compounds which tend not to be biodegradable may be discharged directly into the environment where they spread, even entering the food chain [ 50 ]. Many of these chemicals are hazardous to human health, for example brominated flame retardants are endocrine disruptors and neurotoxins [ 51 ]. Therefore, the use of certain additives combined with poor wastewater management affects not only the health of textile workers, but also that of the communities living nearby.
These issues have encouraged researchers to seek biobased alternatives that are safe and biodegradable. For example, some lignin-based compounds are effective as flame retardants [ 52 ] and biobased carriers have also been described for dyeing [ 53 ]. However, the challenge for most biobased chemicals is cost-effective and sustainable production [ 22 ], which requires meticulous evaluation by LCA.
The sustainability of textiles at the finishing stage would be improved by avoiding the use of hazardous chemicals, which would satisfy circular design practices [ 54 ] by allowing clothing to be recycled without polluting the recycling streams.
Sustainability would also be increased by reducing complexity, for example by using fewer chemicals and avoiding fiber blends, which is also beneficial in terms of circularity.
Such an approach would require transparency accurate listing of the chemicals and fibers used in each garment and traceability throughout the value chain, for example by incorporating aspects of blockchain technology [ 55 ]. The different steps in the textile value chain are often carried out in different countries or regions. Not all countries have oil reserves, so oil is extracted in one place and transported to another for refinement and the production of chemicals such as PET.
These are then shipped to multiple sites for distribution to retailers. The transport sector in general consumes approximately one-third of all energy consumed in the EU, more than million tons of CO 2 equivalents per year [ ].
It is difficult to determine how much of this can be attributed to textiles, although calculations are available for specific sectors: for example, shipping textile products from China generates 0. As stated above, spillages of oil, chemicals and PET pellets often occur during transportation. Legal enforcement on a global scale could help to reduce spillages or force remedial action when spillages occur but overall the best approach to reduce the environmental impact of transport costs is to build shorter supply chains between the industries involved in textile manufacturing.
This would also improve traceability. Additionally, the probability that different countries share a similar legal framework for its manufacturing practices is higher in shorter supply chains, and it is therefore easier to hold them accountable.
For a long time, retail has operated under a fast fashion business model, causing garment consumption to increase and sustainability to fall [ 57 ]. More recently, sustainable fashion has emerged as part of the slow fashion movement [ 58 ]. This advocates for better purchase options based on:. The slow fashion trend has also led to greenwashing —false claims of sustainability to improve brand reputation [ 59 ].
In order to avoid this, traceability must be enforced by strict legislation to preserve the credibility of eco-labeling, which is easier in shorter supply chains as stated above. Another issue is that customer choice is often driven by price and personal preference, even if the consumer is environmentally conscious [ 60 ]. Clothing stores should therefore embrace sustainability and include an educational component to assure customers they are getting value for money when purchasing eco-labeled products.
The most sustainable options for polyester garments are recycled and second-hand clothing. However, the former may be associated with poorer quality and the latter are often sold in lower-profile shops [ 61 ]. Incorporating reused or recycled clothes among clothes from virgin materials in a regular store could help to destigmatize and normalize such garments.
This would also make the purchase of sustainable clothes easier for the customer. Furthermore, most global fashion brands are known for their poor working conditions both for retail and factory staff and failure to embrace ethical fashion. Other business models are emerging, such as systems based on pre-orders to reduce pre-consumer waste, and understanding fashion as a service through rental or subscription-rental.
Leasing clothes instead of selling them would increase the lifespan of a garment and ensure appropriate disposal at their end of life. The initiative Fashion for Good published a report that confirmed the financial viability of such circular models for established retailers [ 62 ], although further research on environmental sustainability is required because rental models would also increase the frequency of laundry and transport.
LCA in the textile industry has traditionally focused on water and energy consumption during the use phase, due to laundry, drying and ironing [ 63 ].
The energy efficiency of these processes has significantly improved over the last few years [ 29 ] and attention has shifted towards microfiber release from the garment to the environment [ 34 ].
Furthermore, the use of laundry detergents has been linked to freshwater pollution and eutrophication [ 64 ]. The total consumption of resources will ultimately depend on user behavior e.
These diverse factors make it difficult to estimate an average annual consumption [ 66 ]. The load capacity was 6 or 7 kg and the project tested different models from all known manufactures in the European market. For the full-load tests, the water consumption was 35—50 L per wash, with an average of 49 L. For the half-load tests, water use was only Water consumption by washing machines in different regions of the world has been evaluated based on data published up to [ 65 ].
The average water consumption per wash was 60 L in Europe where horizontal-axis washing machines are dominant and L in North America where vertical-axis washers are more common. Based on assumed laundry frequencies, this represents 10, L per year for European households and 41, L per year in North America.
Despite the assumptions and the outdated data, these results are qualitatively valuable because they reflect how water consumption per wash cycle depends on equipment vertical-axis machines consume more than twice the amount of water as horizontal-axis machines and how annual water consumption is determined by consumer behavior. For example, Japanese consumers often drain greywater from the shower into the washing machine [ 65 ].
Greywater reuse is not universal but it is common practice in countries with scarce water resources such as Israel and Australia [ 68 ]. Similarly, the European Parliament has recently approved a law for the safe reuse of treated wastewater in agriculture [ 69 ].
Rainwater collection for laundry has also been proposed [ 70 ]. Together with the higher energy ratings of equipment 20—30 years ago, the use phase was declared more environmentally harmful than the production phase. Accordingly, work focused on improving the efficiency of washing and drying machines.
Most washing machines and tumble dryers currently on the European market are rated A [ 29 ]. Tumble dryers consume around five times more energy than washing machines [ 29 ], but this can increase to 15 times more for cotton fabrics, which take longer to dry than polyester [ 75 ].
Air-drying significantly reduces energy consumption during the use phase of any garment, but this is not possible in all climates. Indeed, tumble dryer use is more common in European countries with colder climates and rarer when the climate is warm [ 8 ]. Ironing is projected to consume an average of 1. However, polyester garments do not require ironing as frequently as other fabrics. The environmental impact of the use phase in terms of resource depletion has been proposed to depend on the following hierarchy of user choices: 1 air vs tumble drying; 2 temperature of washing; and 3 equipment efficiency [ 76 ].
These authors argue that consumers with A rated machines may wash clothes more frequently and at warmer temperatures in the mistaken belief that their high-efficiency equipment would compensate for these choices, which in sustainability science is known as the rebound effect [ 77 ].
Appropriate communication and consumer education on sustainable choices is therefore essential to minimize energy consumption during this phase, also reducing CO 2 emissions when energy is provided by fossil fuels. The overall environmental impact of laundry depends on the type and amount of detergent used, both in terms of resources consumed during production and the pollution of water and land during the disposal of wastewater. Among four forms of detergent liquid, powder, capsules and tablets , the production of tablets was shown to generate the highest greenhouse gas emissions [ 78 ].
Similarly, the components of the detergent e. Once a laundry cycle is finished, detergents remaining in the wastewater are either discharged directly into the environment or partially removed in a treatment plant to mandated levels depending on the region. However, given the large volume of laundry wastewater that must be treated, significant amounts of detergent still end up in the environment even after processing, putting aquatic and terrestrial ecosystems at risk [ 64 ].
Surfactants and their byproducts reduce water quality and oxygenation, which can severely damage aquatic animals and plants. Furthermore, some detergent components appear to be endocrine disruptors, affecting the reproductive system of fish [ 80 ]. Detergents containing phosphates cause freshwater eutrophication, and such products have been banned in some countries [ 81 ].
Biobased detergents may be less toxic than their synthetic counterparts [ 79 ]. However, further research is needed to determine which types of detergent are more sustainable, taking into account the production stage, the environmental effects of released wastewater, and also the effect of different detergent packaging materials.
Sustainable detergents should be effective and affordable to compete with their non-sustainable counterparts. Garments are exposed to various mechanical forces during their use phase.
For example, rubbing causes the ends of some fibers to be drawn from the body of the fabric onto the surface, where they appear as fuzz [ 82 ].
All textiles produce fuzz to some extent, but the amount produced and the strength of the protruding fibers depend on the properties of the textile, such as fiber material, yarn characteristics, fabric construction and age. If further mechanical or chemical stress is applied into the textile, the protruding fibers might break, leading to the release of microfibers into the environment [ 83 ].
Another hypothesis is that the fibers protruding from the surface are simply pulled or loosened from the yarn, shedding without breaking [ 84 ]. Regardless of the mechanism Fig. Schematic representation of the proposed source of microfibers. Adapted from [ 83 ].
Microfibers can be released into the air when garments are worn, and also into the water during washing and drying, in the latter case often accumulating as lint. Approximately equal quantities of microfibers are released during garment wearing and during washing [ 32 ]. However, research on the source of microfibers released into the environment has typically focused on detachment during laundry cycles, including the effects of temperature, detergent and the type of washing machine.
Many different factors contribute to fuzz formation and fiber release, so we will assign them to two groups: textile parameters and external parameters Table 1. In this article, the latter refer solely to the effects of laundry, because the release of microfibers into the air during wearing has not been studied in detail. It is difficult to reach a consensus on the quantity of microfibers shed by different garments during laundry because multiple textile and external parameters act in concert, and there is no standardized method to test, measure or analyze microfiber release, leading to diverse results.
For example, one study reported the shedding of — mg microfibers per kg polyester fabric during a laundry cycle, which corresponds to ,—1,, individual fibers [ 84 ], whereas another reported the shedding of 0. The first report quantifying the release of microfibers in washing machines estimated microfibers per wash per synthetic garment [ 87 ].
Several recent studies have considered the influence of textile parameters on microfiber release [ 32 , 83 , 84 , 85 , 86 , 88 , 89 , 90 , 91 , 92 ].
The testing of polyester garments with different yarn characteristics and fabric constructions revealed that yarns with a higher twist released fewer microfibers than those with lower or no twist, regardless of whether the fabric was knitted or woven [ 84 , 88 ]. This suggests that tighter yarns make it more difficult for individual fibers to slip or protrude from the fabric.
Furthermore, fiber length can influence how much fuzz is produced in the first place. Fabrics with yarns made of staple fibers shed more microfibers than those made of continuous filaments, because in the latter fewer loose ends protrude from the surface [ 85 ].
Polyester is often blended with cotton in the textiles industry and two studies have considered polyester and cotton garments with the same yarn and fabric construction, both finding that cotton released more microfibers than polyester [ 83 , 84 ]. This was attributed to polyester having a greater resistance to breaking [ 83 ] and to the cellulose fibers of cotton being less hydrophobic [ 32 ].
The latter would cause cotton fibers to swell more in water, not only exposing them to breakage but also generating more space for microfiber movement. Another study found that polyester fabrics released more microfibers than cotton, but did not account for different yarn characteristics [ 86 ]. Finally, the age of the garment has also been evaluated as a factor influencing the release of microfibers during laundry. The quantity of microfibers released during laundry decreases after the first wash until it reaches a plateau [ 83 , 84 , 85 , 86 , 90 ].
However, these sequential wash cycles did not accurately represent the aging of garments because there was no interstitial use, and therefore little opportunity to generate fuzz. Even so, it is not clear whether mechanical aging is an accurate simulation of natural aging, and further testing is required under more realistic aging conditions to determine how microfiber release varies during the life of a garment.
The effect of different external parameters on the release of polyester microfibers has been tested in both laboratory simulated washers [ 83 , 85 , 89 , 90 ] and in real commercial household machines [ 32 , 83 , 86 , 90 , 91 ]. Home laundering experiments are often used to quantify microfiber release because they offer a realistic scenario, but there is a good correlation between the two kinds of experiments suggesting laboratory models are also representative [ 83 , 90 ].
The advantage of laboratory studies is that external parameters are easier to control and the washers are simpler to operate and allow the better recovery of samples for analysis [ 83 ]. Laboratory studies also address the need for standardization [ 85 ]. Home laundry experiments have considered the impact of different types of machines. For example, one study compared microfiber release in vertical-axis machines with a central agitator and horizontal-axis machines [ 91 ].
Settings for wash volume, temperature and wash cycle duration were similar in both machines. Speed was only stated for the vertical-axis washer with the central agitator, which shed approximately seven times as many microfibers as the horizontal-axis machine. The authors proposed that the central agitator may have caused more intense movement in the water compared to the horizontal drum, causing more damage to the garments. Based on the hypothesis that mechanical stress from the laundering processes is responsible for the release of microfibers, polyester garments were tested in washing cycles of 1, 2, 4 and 8 h, to confirm that longer washes lead to more shedding [ 89 ].
However, the authors found that a similar amount of microfibers was released regardless of the washing time, and thus the total amount of agitation.
Similarly, no significant difference was observed between wash cycles lasting 15 and 60 min [ 90 ]. Synthetic-based clothing is one the largest microplastic polluters in the oceans which happens through wash-off of around 1, fibers from just one clothing item in every wash. Currently, the biggest producer is China, whilst Japan, India, Indonesia, and the United States are also large producers of polyester.
Due to its versatility and desirable qualities, polyester is used in many cases. High tenacity and durability make it very appropriate for clothing production.
As a strong fiber, polyester can withstand strong and repetitive movements. Its hydrophobic water-repelling property makes it ideal for garments and jackets that are to be used in wet or damp environments, coating the fabric with a water-resistant finish intensifies this effect. In the fashion industry, this fibre is mainly used for making shirts, trousers, suits, bags, footwear, sportswear, bed sheets and so on.
For industrial use, it is used for making air filters, carpets, ropes, films, fishing nets, bottles, high-quality wood guitar finishes, pianos, liquid crystal displays, wire, phone cases and many more. Polyester fibres are sometimes spun together with natural fibres to produce fabric with blended properties. Wool and cotton can be a good example as when they are blended together, it improves crease resistance. As mentioned, polyester is very durable, resistant to many chemicals such as hydrogen peroxide, lubricants acids etc.
It is also very lightweight, which is another important advantage. Close and accept. CO Expo. About CO. Petrochemical origins and impacts Polyester is made through a chemical reaction involving coal, petroleum from crude oil , air and water. Limitations of recycling Most polyester used in clothing currently is virgin polyester. Your washload, microplastics and marine pollution Microplastics are plastic particles of less than 1mm in diameter. References 1. Sustainable Apparel Materials 3.
Environmental Sciences Europe Analysis of the polyester clothing value chain to identify key intervention points for sustainability 4. Mistra Future Fashion Microplastics shedding from polyester fabrics 5. Social Share.
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