What is Cotton Fibre?
Cotton fibre is a natural, soft and fluffy staple fibre that is harvested from the seedpods of the cotton plant. The cotton plant belongs to the genus Gossypium, which is a member of the mallow family Malvaceae. Cotton falls into the category of seed hair, the only other fibre of this type being Kapok. However, unlike cotton, Kapok is very short length fibre and quite weak. The cotton fibre is most often spun into yarn or thread and is used to make a soft, breathable textile. The cotton is most widely used natural fibre in clothing today.
Cotton fibres are composed primarily of cellulose, which is a complex carbohydrate that gives cotton its strength and durability. Cellulose is a long chain of glucose molecules, which are linked together by chemical bonds. These bonds make the fibres strong and resilient, yet flexible.
The cotton fibers are usually about 1-1.5 inches long, but can be longer. They are usually white, but can also be various shades of brown, yellow, green, or gray. They are also smooth and lustrous.
Cotton fibres are used to make a wide range of products, including textiles, clothing, and other household items. Cotton is considered as the most important natural textile fibre in the world. It is also known for its breathability, absorbency, and softness. It is also hypoallergenic and resistant to wrinkles. Due to its properties, it is widely used in clothing, bedding, and industrial products.
Cotton is a renewable resource and is grown in many parts of the world. It is a major crop in countries such as the United States, China, India, Pakistan, and Brazil. The cotton is generally grown in the warm climates, it is a water-intensive crop, and it is often heavily sprayed with pesticides and fertilizers.
Types of Cotton Fibre:
There are several types of cotton fibre, each with its own unique characteristics and uses. The main types of cotton fibre are:
1. Upland cotton: This is the most widely grown type of cotton and is responsible for the majority of cotton production worldwide. Upland cotton is known for its high yield and is used to make a wide range of products, including textiles, clothing, and other household items.
2. Pima cotton: Also known as extra-long staple cotton, Pima cotton is known for its long fibres, which make it stronger and more durable than other types of cotton. It is also known for its softness and is often used in high-end clothing and bedding.
3. Egyptian cotton: This type of cotton is known for its long and extremely fine fibres, which make it extremely soft and durable. It is often used in luxury bedding and clothing.
4. Organic cotton: Organic cotton is grown without the use of synthetic pesticides and fertilizers. It is considered more environmentally friendly and is often used in clothing and other products that are marketed as “green” or “eco-friendly”.
5. Supima cotton: This is a brand name for the type of extra-long staple cotton grown in the USA. It is considered one of the finest cotton fibres in the world, and it is known for its strength, softness, and color retention.
6. BT cotton: BT cotton is a type of genetically modified (GM) cotton that has been engineered to include a gene from the bacteria Bacillus thuringiensis (BT). This gene produces a toxin that kills certain pests that feed on cotton plants, such as the bollworm.
7. BCI cotton: BCI stands for Better Cotton Initiative, it is a sustainable cotton, grown with fewer pesticides and more water-efficient methods. This cotton is also known for its environmental sustainability, as it helps in reducing the environmental impact of cotton production.
Properties of Cotton Fibre:
Cotton fibre has several properties that make it a popular choice for textiles and other products:
- Softness: Cotton fibres are naturally soft and comfortable to the touch, making them ideal for clothing, bedding, and other household items.
- Absorbency: These fibres are highly absorbent, which means they can hold a large amount of water. This makes cotton fabrics breathable and comfortable to wear.
- Strength: They are strong and durable, which means they can withstand repeated washings and wear.
- Hypoallergenic: Cotton fibres are hypoallergenic, which means they are less likely to cause allergic reactions.
- Resistant to wrinkles: Cotton fibres are naturally wrinkle-resistant, which means they can maintain their shape even after being washed or worn.
- Biodegradable: Cotton are biodegradable, which means they can break down naturally in the environment.
- UV-Resistant: Cotton fibres have natural UV resistance and can block out some of the harmful rays of the sun.
- Easy to dye: They are easy to dye, which means it can be colored in different ways, making it versatile and can be used in a variety of clothing.
- Low lint: Cotton fibres have low lint, which means they are less likely to leave fibres behind when washed or worn.
- Renewable Resource: Cotton is a renewable resource and is grown in many parts of the world.
Molecular Structure of Cotton Fibre:
Basically cotton contains 91% of cellulose, 7.8% water and the remaining is pro-toplasm, pectin, waxes, fatty substances and mineral salts. As mentioned earlier, cotton is basically a chain of glucose units. During linking, two OH groups join and form water. The linking of two residual molecules – called as ‘cellobiose’ – is as shown in below Figure, in that they turn through 180°. These form the main foundation for cellulose.
The process of condensation (joining of the molecules) continues and a much longer chain is formed – ‘condensation polymer’. The Degree of Polymerization (number of repeating units) in cotton is very large (2000–4000), while with re-generated cellulose (Viscose), is only 300–400. Whereas alkalis have no damaging effect, acids can reverse the condensation process, reducing the chain length and damaging the fibre.
Cultivation of Cotton Fibre:
Cotton is a warm-season crop that is typically grown in regions with long growing seasons, abundant sunlight, and moderate to high temperatures. The primary regions for cotton cultivation include the southern United States, China, India, Pakistan, and Brazil.
The cultivation of cotton begins with the planting of seedlings in well-prepared fields. The seeds are usually planted in rows and are spaced apart to allow for proper growth and development. Once the seedlings have emerged, they are irrigated and fertilized to promote healthy growth.
As the cotton plants mature, they begin to produce clusters of white or yellow flowers. These flowers then give way to the cotton bolls, which are the seedpods of the cotton plant. The cotton fibres are found inside the bolls, and they are surrounded by a protective layer of fibres called the lint.
Cotton fibres are harvested by either picking the cotton by hand or by using a cotton picker, a machine that removes the cotton fibres from the bolls. After harvesting, the cotton fibres are cleaned, carded, and spun into yarn or thread.
Cotton is a water-intensive crop, and it is often heavily sprayed with pesticides and fertilizers. This can have negative impacts on the environment and on the health of farm workers. As a result, many cotton farmers are now using more sustainable practices such as drip irrigation, integrated pest management, and reduced tillage. These practices can help to reduce water usage, reduce chemical inputs, and improve soil health.
Uses of Cotton Fibre:
Cotton fibres are one of the most versatile natural fibres and are used in a wide range of products, including:
- Clothing: Cotton fibres are used to make a wide range of clothing, including t-shirts, jeans, dresses, and other types of apparel.
- Home textiles: Fabrics are made from cotton are used to make bed sheets, pillowcases, towels, and other household linens.
- Industrial products: Cotton fibres are used to make industrial products such as ropes, twine, and canvas.
- Personal care products: Cotton are used to make personal care products such as cotton swabs, cotton balls, and medical bandages.
- Paper: Cotton are used to make high-quality paper products such as banknotes, currency, and fine art paper.
- Automotive products: Cotton fibres are used to make automotive products such as seat covers and upholstery.
- Footwear: They are used to make the inner soles of footwear.
- Furniture: Cotton fibres are used to make furniture such as cushions and upholstery.
- Agriculture: These fibres are used to make agricultural products such as seed bags and animal feed bags.
- Packaging: Cotton fibres are used to make packaging products such as bags, sacks, and wrapping materials.
References:
- Principles of Spinning: Fibres and Blow Room Cotton Processing in Spinning by Ashok R. Khare
- Textile Raw Materials By Ajay Jindal and Rakesh Jindal
- Textile Engineering – An Introduction Edited by Yasir Nawab
- Fibres to Fabrics by Bev Ashford
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