Project Description

Cotton

Gossypium arboreum, commonly referred to as tree cotton, is a perennial native to India, Pakistan and  tropical and subtropical regions of Asia, Europe and Africa. Tree cotton is a member of the Malvaceae family and one of four species of cotton in cultivation. This shrub can reach about 2 m high and can tolerate drought, pest-resistant but is sensitive to frost. It has purple branches and green leaves. It produces yellow flowers sometimes with purple centre.

Tree cotton have green fruits (capsule) that dies up and opens to release the seeds that are covered in long white woolly hairs called cotton. This cotton is used to made fabrics and the process is described below. However, there are other uses for cotton. In India, the root of the tree is used to reduce fevers and the seed to treat gonorrhoea, gleet, chronic cystitis, catarrah and consumption. The cotton seeds can also be used to obtain oil that is used in food products such as mayonnaise, shortening and salad dressing.

How cotton yarn and fabrics are made

Prior to the discovery of cotton as a material for making yarn, the ancient method of making yarn involved the use of animal fibres and twisting it around spindles made of sticks. 500 BC in India, out came the spinning wheel which the concept is still used today in making yarn but now it is fully automated.

To make 2-ply commercial yarn, the type for making clothing fabrics, it begins with large quantities of raw cotton.

  1. Cotton is the fruit harvested in the fields from the floral component of the cotton plant.

  2. To remove stems, leaves and dirt that may be trapped in the cotton, a machine picks up 5mm thick layers of lint at a time to be sent for cleaning and blending. That’s 500 kg of cotton fibre processed per hour.

  3. As cotton passes through a carding machine, the machine combs the fibres into an even layer by length

  4. Next a coiler machine form a loose primitive yarn called “sliver”.

  5. Drawing machine assembles 6 slivers at a time and stretches them together to form a stage 2 yarn.

  6. The 2nd stage yarn is twisted and stretched further to strengthen it into 3rd stage yarn.

  7. 3rd stage yarn called “roving”, is where automated spindles are spun quickly to form large spools of yarn. 3.5 to 16 times thinner than the primitive yarn.

  8. After stretching the roving one last time the yarn is finally finished.

The finished yarn is 200 times lighter than the primitive sliver and start to finish take approximately 48 hours. All that is left to turn the yarn into fabric is attach the yarn to automated looms which weave the yarn into all sorts of cool patterns and designs!

Due to the popularity of using cotton as fabrics, recent research has been looking into producing flame retardant cotton materials by infusing it with durable and organic polymers.

Works Cited

PROTA4U. n.d. Gossypium arboreum L. http://www.prota4u.org/protav8.asp?en=1&p=Gossypium+arboreum

The Permaculture Research Institute. n.d. Tree Cotton – Gossypium Arboreum. http://permaculturenews.org/2012/04/05/tree-cotton-gossypium-arboreum/

Yang, H., & Yang, C. Q. (2005). Durable flame retardant finishing of the nylon/cotton blend fabric using a hydroxyl-functional organophosphorus oligomer. Polymer Degradation and Stability. 88; 363-370.