Fabric series: All about Denim
Denim jeans, jackets, skirts, shirts, caps etc. are all established clothing items in today’s fashion world. From children to the older generation, everyone has at least one denim piece in their wardrobe.
What is Denim?
Denim is a durable cotton or cotton-blend twill (twill is a type of weave) textile, typically used to make jeans, overalls and other types of clothing. It is a strong fabric made using the warp and weft weaving method which results in a diagonal denim ribbing.
In the US, denim has been used since the mid-19th century. At that time, clothes for workers such as miners, surveyors, etc were not so durable. In 1873, a tailor from Nevada, Jacob W. Davis manufactured the first pair of denim trousers. He got the inspiration for making these jeans from a woman who approached him to make durable trousers for her husband for wood chopping. After the increased popularity and demand, Davis’s small tailor shop did not have enough capacity to produce and meet the demand. This situation made him to approach Levi Strauss & Co. to manufacture the material which was patented by Davis. The promising business opportunity lead Levi Strauss & Co. to hire Davis as a head of mass production in San Francisco.
How is Denim made?
To create denim, cotton passes through several stages: Harvesting the cotton, separating the cotton fibre from its seeds, making yarn, dyeing yarn and finally treating (sanforisation) the yarn to avoid shrinking of the textiles. Sanforisation is the process patented by Sanford Lockwood Cluett which is the method applied to cotton and other textiles made from natural or chemical fibres. This is the treatment process of shrinking, stretching and fixing it to prevent shrinking during the first wash.
Yarn production
Denim yarn is almost entirely composed of cotton. Some denim yarn might include an elastic component of up to 3%, such as spandex, to allow the final woven product to stretch. Spandex or elastane is a synthetic fibre, which is exceptionally elastic. Even a small amount of it could increase the stretching capacity up to 15%.
Dyeing
There are two types of denim dyeing: Sulphur dyeing and indigo dyeing.
Indigo dyeing is a traditional way of dyeing, mostly to shades of blue. Indigo dye is made out of plants which are included in the Indigofera family. In South East Asia, this dye is made from dried and fermented leaves of Indigofera tinctoria, and the method has become common practice globally. The indigo method is currently the most preferred method by almost all producers. Although originally this dye was made from natural sources, currently most denim is dyed with synthetic indigo dye. The one thing that does not change is the process, where the yarn undergoes a repeated sequence of dipping and oxidation — the more dips, the stronger the color of the indigo.
Sulphur dying is also known as color dying and used for creating specific colored denim such as black, white, pink, mustard and namely others.
Weaving
After the production process the yarn is transferred to fabric form by weaving. In technical terms, weaving is the process of interlacing two sets of yarn at a fixed 90° angle.
There are two sets of yarn which perform different kinds of tasks. The first one is weft, where the yarn goes across, and the second one, where it is threaded under and over the yarn which goes downwards - these are called ends or wrap. The method is known as the wrap and weft method.
Who produces it?
Currently, North America, Turkey, India, Pakistan, Brazil, Italy, China, Bangladesh, Japan and Sri Lanka are the top 10 denim manufacturers in the world.
Denim and the Environment
As already mentioned, denim is a cotton-based textile. The production of denim requires cotton, and cotton requires a lot of water (see more about cotton here). 5,700 litres of water are needed to make one pair of jeans. Americans buy 4 pairs of jeans a year on average, and 300 million pairs of jeans are made in China every year. There is also a documentary about environmental damages to rivers, communities, ecosystems in India, Bangladesh and China, called “The RiverBlue: Can Fashion Save the Planet?”. According to this documentary, approximately 70% of rivers in Asia are polluted by the 2.5 billion gallons of wastewater created by the textile industry.
That’s not all. Campaigners from the environmental group Greenpeace, who tested the outflows near dyeing and finishing facilities in the top denim producing towns in Asia, found five heavy metals (cadmium, chromium, mercury, lead and copper) in 17 out of 21 water and sediment samples, taken from throughout Xintang, one of the locations featured in the project.
Another issue worth mentioning is denim sandblasting. In order to give denim an old, worn look, fine sand is taken and sprayed under very high pressure onto the denim. This cheap and quick method contains very toxic and dangerous ingredients to the health of the workers who do this procedure.
Last but not least, the term textile waste also contains denim products. To know more about textile waste, check out our The Impact of Clothing Waste post.
What is Denim used for?
Denim is a multipurpose fabric. It is used for making clothes, accessories, furniture, vehicles, to name a few. For example, jeans, dresses, hats, jeggings, jackets, shirts, suits, and sneakers can be made from denim. Tote bags, belts, handbags, rucksacks and even sunglasses can also be made from denim. On vehicles, it was firstly produced by American Motors (AMC) by the collaboration with Levi’s in 1973. Fabrics for car seats were made from denim material. Lampshades, bean bag chairs and upholstery can be examples for furniture.
Can Denim be recycled?
Globalisation and compulsive consumer behavior along with increasing population are all accelerators of environmental crises. In today’s world, denim is an inevitable part of our life, but can they be recycled?
Used and old denims can be creatively recycled into very useful products. Recycled denim is obviously better as recycling consumes much less energy than producing new ones and contributes to decreasing waste in landfills. Usually, all denim garment pieces can be recycled and produced again into the fashion market as clothes, accessories etc. Let’s look at some examples of recycled denim:
Recycled denim can be used for wall insulation for homes, hotels, offices etc. These insulation materials are made up of 85% factory scraps consisting of cotton fibers, and natural denim. Approximately 300 tons of waste denim generally used for landfill can be transformed into insulation material, and 500 pairs of jeans can completely insulate one home. For example, in 2011, Levi Strauss & Co. launched a 100 thousand US dollars insulation fund to recycle unwanted and used denim while keeping it out of landfills.
Another example would be Ford Focus cars. The company uses recycled cotton from used blue jeans as a carpet backing, sound absorption in their cars.
Wearing recycled denim is cool, stylish and most importantly is a contribution to the environment. Recycled products are a very important way to reduce carbon footprint.
Stay stylish and sustainable!
Sources:
https://www.levi.com/US/en_US/features/denim-dictionary
https://www.fibre2fashion.com/industry-article/5401/recycle-reuse-and-reduce-new-life-for-old-denims
https://www.denimhunters.com/denim-wiki/denim-explained/indigo/
https://www.denimhunters.com/denim-wiki/denim-explained/weaving/
https://www.watchriverblue.eco/
https://www.ecowatch.com/environmental-cost-jeans-2544519658.html
https://denimmanufacturer.net/top-10-denim-manufacturing-countries/
https://fashioninsiders.co/features/opinion/how-denim-manufacturing-impacts-the-environment/