Polyester is a synthetic fabric derived mainly from petroleum. It is one of the world’s most popular textiles, and it has a multitude of consumer and industrial applications. Despite its worldwide fame, its manufacture comes with a hefty environmental cost. Whilst polyester could be classed as a virgin fabric, Repreve is a recycled polyester brand name by Unifi, an American fiber manufacturer. Unifi manufactures Repreve out of recycled plastic chips made from polyester waste such as plastic bottles. Finished fabrics can either be 100% Repreve or a hybrid with virgin polyester or other fibers (such as Spandex). It is used to create fabrics for athletic and fashion clothing as well as upholstery. Launched in 2017, Repreve is now the world’s leading, branded recycled fiber. We will delve into the differences and similarities between Repreve and Polyester in this article.
image source: fashionatingworld.com Introduction to Repreve and Polyester The earliest record of polyester creation dates back to 1940 when American company DuPont wanted to make textile fibers using polyester. DuPont trademarked its creation with the name Mylar and received registration in the year 1952. Meanwhile across the water, British chemists John Rex Whinfield and James Tennant Dickson were at the same time inventing the same compounds which resulted in polyester. Concurrently, in the Soviet Union, PET was manufactured at the Institute of High-Molecular Compounds in the year 1949. This institute was part of the USSR Academy of Sciences. Fast forward to today, the global production for polyester reaches almost 80 million tons per annum. Polyester can be produced via two methods, one using ethylene glycol and dimethyl terephthalate, and the second using ethylene glycol and terephthalic acid. In the first process, dimethyl terephthalate and ethylene glycol are allowed to react in the presence of a basic catalyst at a temperature of about 150oc to 200oc. Methanol is distilled out and then excess ethylene glycol is distilled with the help of a vacuum. This process of producing polyester is also known as the transesterification process. In the second process, ethylene glycol and terephthalic acid are allowed to react at high temperature and moderate pressure in a process known as esterification. Water is removed via distillation during the process. Repreve fabric is created at Unifi’s advanced recycling facility, where plastic bottles are sorted, washed, and chopped into flake material. The clean flake is blended, melted, and turned into Repreve recycled chip and loaded in silos. One silo can hold the equivalent of 27 million plastic bottles. The chip goes through the extrusion and texturing process and is transformed into fibers with inherent performance properties. For dyeing, an innovative process called Waterwise may then be used. Color is blended into the fibers, offering long-lasting, vibrant fabric colors with a waterless dyeing process that conserves natural resources. The solution dye becomes part of the fiber as it's being extruded, resulting in rich, brilliant, long-lasting color. Similarities Between Repreve and Polyester
Both are made from polyester, a man-made synthetic fiber.
Both are durable and long-lasting fibers.
Both are easily blended with other fibers such as cotton, to improve their breathability.
Neither of these fabrics biodegrades easily due to being man-made.
Both of these fibers are entirely vegan, as no animal husbandry is required in their production.
They are both water-resistant, fight against odors, and lightweight.
They both have multiple applications - in fashion, activewear, upholstery, outdoor gear, and car interiors.
Differences Between Repreve and Polyester
Producing Repreve offsets the need to produce new petroleum, emitting fewer greenhouse gases and conserving water and energy in the process. This is in stark contrast to virgin polyester which requires the petrochemical cycle to continue for its production.
Repreve is a recycled fiber, virgin polyester is not.
Repreve vs Polyester: Environmental Impact To date, Unifi has recycled 10 billion bottles. It diverts plastic waste from landfills to create durable, sustainable fibers that can be used in textile fabrics. Producing one pound of Repreve can
Save enough energy to run a compact fluorescent light bulb for nearly 22 days
Save enough water to provide more than the daily requirements of drinking water for one person
Save the amount of greenhouse gas (GHG) emitted while driving a hybrid car almost 3 miles
It has also received the Oeko-Tex Standard 100 certification, a well-known international eco-label. Oeko-Tex offers “Confidence in Textiles,” ensuring that Repreve's fibers are tested to be free of harmful levels of more than 100 restricted chemicals. The only concern with Repreve is the fact that it requires plastic to be produced, thus continuing the industrial petrochemical cycle. It would be good to see single-use plastics disappearing altogether from our shelves. However, it is a major step in the right direction in terms of sustainability. It tackles a current problem. Repreve vs Polyester: Applications Repreve and polyester have similar applications as they have the same chemical makeup. Repreve is used mainly for apparel, footwear, automotive, contract furnishings, and home textiles. Virgin polyester is used for just about everything you may encounter in your day-to-day life from the clothes you wear to the interiors of your car to the filters, ropes, tents, curtains, and fishnets you may use. The only difference is that Repreve isn’t as widely available as polyester, but brands are quickly getting on board with Repreve.
Image source: http://schwartz.eng.auburn.edu/polyester/uses.html Repreve vs Polyester: Conclusion We have compared the similarities and differences between these two types of polyester, one of which requires raw materials and one which is recycled. Repreve is by far the better option when it comes to the environment. Examples of Polyester and Repreve from the Showroom REPREVE® Polyester 167g/s'm Double Weave
Fabric Type: Woven Weave: Double Weave Length: 50 m Width: 140 cm Weight: 167 g/s'm Content: Polyester 56 %, Elastane 8 % Country of origin: Taiwan
REPREVE® Grosgrain
Fabric Type: Woven Weave: Grosgrain Finish: Regular Washing Temperature: Cold Drying: Line Dry Length: 50 m Width: 57 inch Content: Polyester (REPREVE®) 100% Country of Origin: China