Polyester’s positive attributes for clothing lie mostly in the consumer use phase of its lifecycle, which accounts for 50-80% of a polyester garment’s total ecological footprint. Polyester garments are generally washed in cold water and drip-dried, thereby minimizing water and energy use associated with garment care.[4]
In comparison to other synthetic fibres, there is currently more research and innovation when it comes to sustainability and improving polyester’s environmental impact.
==Manufacturing ==
PET is made from ethylene glycol and terephthalic acid. From that polymer, fibers are made by a [[melt-spinning]] process, mostly in a continuous line with both the polymerization and melt spinning. The high speed at the [[spinning]] process requires the use of lubricants (spinning oils). They are commonly made of mineral oil with the addition of surfactants to facilitate the washing-out process when dyeing. In order to avoid that the fiber turns glassy (shiny) a matting agent in the form of titanium dioxide, or silicates are added, also optical brighteners are added. For the polymerization one needs small amounts of metal catalysts and at the end of polymerization one also needs a “catalyst-poison” in order to get the correct chain lengths.
== Potential impacts ==
Petroleum, the main ingredient in manufacturing polyester, is a non-renewable resource and mining for petroleum destroys natural habitats. That is to say that petroleum takes millions of years to form, and is currently being extracted from the earth for industrial uses faster than it can be replenished. The declining petroleum supply is the source of much debate—British Petroleum (BP) reports that there are 1,333 billion barrels still available to pump (enough for 40 years at current usage rates).[5] Other sources state that supply is overestimated and that reserves are about 30% lower than widely reported.[6]
The manufacturing process for polyester is fully chemical, energy intensive and releases greenhouse gasses into the environment.[7]In the production of polyester, the main ingredients used are terephthalic acid (TA) or dimethyl terephthalate, which are reacted with ethylene glycol, based on bromide-controlled oxidation.[7 ] The production of polyester emits emissions to air and water, which include: heavy metal cobalt; manganese salts; sodium bromide; antimony oxide; and titanium dioxide.
Antimony is of particular concern, since it is a toxic heavy metal known to cause cancer under certain circumstances and is a suspected reproductive toxin.[7] The function of antimony in the production of polyester is as a catalyst in the oxidation process. But it is not absolutely necessary for polyester production, and alternate non-antimony catalysts are available.
Europe meets its oil consumption/needs by importing from foreign sources: 41% from the Russian Federation, 26% from Africa, 16% from the Middle East—14% comes from Europe—thus requiring transportation over long distances.[8][9] Fuel released by vehicles used to transport the oil causes pollution and CO2 emissions.
Discarded polyester products increase load on landfills, contribute to water contamination and possibly toxic emissions into the air.[11] According to a study done by Mark Browne, an ecologist at University College Dublin, microscopic fragments of polyester, acrylic, polyethylene, polypropylene, and polyamide have been discovered in increasing quantities across the northeast Atlantic, as well as on beaches in Britain, Singapore and India. A chemical analysis revealed that nearly 80% of the filaments contained polyester or acrylic.[12]
== Alternatives to virgin polyester ==
Teijin recently established a joint venture with one of China’s largest fibre producers, bringing the manufacture of chemically processed recycled polyester to China.[15]
{| class="wikitable"
== Alternatives to virgin polyester ==
=== Biopolymer fibres fibers ===
==== Polylactide (PLA) ====
Polylactide (PLA) is a renewable thermoplastic and a polymer. It is derived from the starch of plants such as corn, sugar cane and sugar beet. PLA is biodegradable, as it decays as a result of exposure to heat and moisture. It decomposes forming carbon dioxide and water, which present no danger to the environment.[16][17]
==Innovation opportunities==
==Company 1. Although creating different blends of recycled polyester with recycled cotton, organic cotton, etc., is good in the short term, know that these blends make it difficult to recycle at End of Use stage, and create liabilities and waste. When designing fibre blends, consider what happens after End of Use. 2. Design garments and products with reusable elements and for easy disassembly. Design the product so that trims, tags, buttons, etc. can be easily separated from the main body of the product at the end of its useful life, to enable easy in-house recycling. Create collection systems for the products. Collect, disassemble, reuse. 3. Look for cross-sector marketing opportunities==. For example, partner with a soft drinks brand to use their PET bottles in fabrics, or partner with garment collection charity to establish a long term collection facility where customers can drop their closed loop recyclable polyester garments. 4. Investigate alternative technologies for colouring polyester fabrics, such as AirDye, which eliminates water from the dyeing process.[17] Explore unique aesthetics achieved from using this process. 5. Design garments that are 100% polyester, including trims, so garments can be chemically recycled easily at the end of use. 6. Design products so that non-polyester trims can be easily separated from the main body of the product at the end use, to enable easy polyester recycling. 7. Design 100% degradable garments that are made from 100% PLA and work directly with the fibre-producing company to ensure performance and proper application. Create in-store take-back program for customers and partner with a local compost facility to ensure optimum conditions for garment to degrade properly. 8. Get your product Cradle to Cradle Certified. The Cradle to Cradle CertifiedTM Product Standard is a multi-attribute, continuous improvement methodology that provides a path to manufacturing healthy and sustainable products. The Standard rewards achievement in five categories and at five levels of certification. An accredited assessor will help to assess and optimize your product.
==Sources==
# https://www.indotextiles.com/download/Fibre%20Year%202009_10.pdf
# https://www.swicofil.com/pes.html
# https://www.nyfashioncenterfabrics.com/polyester-fabric-info.html
# https://www.ecouterre.com/could-polyester-be-the-next-eco-friendly-fabric/
# makewealthhistory.org/2010/06/11/how-much-oil-is-there-left-really/
# https://www.guardian.co.uk/environment/2010/jun/09/sir-david-king-dwindling-oil-supplies
# Athleta Webinar: “Textile Fibres & Sustainability.” Charlene Ducas. October 29, 2012
# “Monthly and cumulated Crude Oil Imports (volumes and prices) by EU and non EU country,” 2012.
# ec.europa.eu/energy/observatory/oil/import_export_en.htm
# Grose, Lynda and Kate Fletcher. Fashion & Sustainability: Design for Change. London: Laurence King Publishing Ltd, 2012.
# https://www.epa.gov/ttnchie1/le/acrylon.pdf
# https://www.ecouterre.com/is-synthetic-clothing-causing-microplastic-pollution-in-oceans-worldwide/
# The Textile Dyer, “Concern over Recycled Polyester,” May 13, 2008,
# oecotextiles.wordpress.com/2009/07/14/why-is-recycled-polyester-considered-a-sustainable-textile/#_ftn6
# https://www.teijin.co.jp/english/news/2012/ebd120809.html
# textileexchange.org/sites/default/files/eco_fibre.pdf
# https://www.technologystudent.com/joints/pla1.html
# Boh, Richard. Personal Interview. 25 February 2014.
# https://www.OEKO-TEK.com/media/downloads/Factsheet_OETS_100_EN.pdf
# http://www.teijin.com/products/chemicals/hmf.html
# http://www.jmcatalysts.com/pct/news2.asp?newsid=65