Why denim recycling is important?
Denim is one of the most used fabrics in the entire world. The volume of denim produced per year is humongous. Also cotton is the fundamental building block of denim production. Cotton production requires a lot of pesticide, insecticide, and water consumption. So the recycling potential of denim fabric has gained a lot of attention lately.
Why cotton cultivation is unsustainable?
57% of cotton cultivation takes place in areas where there is a scarcity of water. Only 30% of cotton is cultivated in rainy areas.
Cotton cultivation requires a lot of pesticides and insecticides. 4% of the world’s total pesticides and 10% of the world’s total insecticides are used for cotton cultivation.
In poorer countries, children under the age of 18 are hired for cotton cultivation, which is a clear violation of labor law.
Why denim production is unsustainable?
One pair of jeans production and day to day care requires 2900 liters of water.
Indigo dye is used to dye denim fabric. Indigo dye is toxic to the environment and effluent water coming from denim dyeing factories often contains this toxicity that is very harmful to the environment.
Often synthetic indigo and sulfur dye are used for effluent that can cause serious harm to the environment.
Nowadays, different types of denim washing are done to give the garment a unique look. For example:
Pumice stone is used for stone washing. During the wash cycle, pumice stone breaks and become powder and gets stuck to the garment. In order to remove the powder, the garment goes through several wash-cycle that causes high water consumption. Again those powdered stone often passes through the ETP and causes environmental pollution.
Sandblasting is another garment finishing process that requires the use of sand. During sandblasting those fine particles of sand spreads in the air, and cause serious harm to the respiratory system of the workers.
Potassium permanganate, bleaching agent, different acids are used during the denim washing process. These are all highly damaging to the environment.
Denim recycling process:
The denim recycling process is not that complicated but recycling is depending on the type of materials used in the fabric. Synthetic fabrics are easier to recycle as they are produced through the melt spinning process. So basically the material can be melted and then passed through the spinneret as new recycled thread.
But the natural and synthetic blend is not recyclable in 90% of case (MUD jeans can recycle 90% cotton and 2% spandex). So for recycling, we need 100% cotton.
The process starts with collecting old denim garments. At first all the accessories like-button, zipper, etc. are removed. Then are passed through several shredders to chop them into smaller pieces. Eventually, they become cotton fiber. Cotton fiber bale is produced from recycled cotton.
This bale is mixed with virgin cotton fiber bale. Only 30% of recycled cotton can be used with virgin cotton as the fiber length, strength, and quality of the recycled cotton is pretty poor.
After blending, lap is produced. Then the fiber passes through carding machine, drawing machine, roving machine, ring frame machine, and recycled yarn is produced. Then this recycled yarn is dyed and finally woven into a fabric.
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