Table of Contents
Physical Properties of Cotton Fiber:
- Length- 0.5 to 2.5 inch.
- Diameter- 16 to 20 microns.
- Cross-section – Kidney shape
- Colour – White, grey, Cream
- Elongation- 6.5 %
- Resiliency – Low
- Specific gravity – 1.54
- Moisture regain – 8.5 %
a. Length and Fineness
Cotton fibers vary in length, typically ranging from 10 to 50 millimeters. Longer fibers are known as staple fibers. Staple fiber is preferred in textile manufacturing due to its strength and durability. Fineness, measured in micrometers, affects the fabric’s texture and feel.
b. Strength and Elasticity
Cotton fibers possess impressive tensile strength. It enables them to withstand stretching and pulling without breaking. However, cotton lacks elasticity compared to synthetic fibers, making it prone to wrinkling and shrinking.
c. Color and Luster
Natural cotton fibers exhibit a creamy white color. But they can also be dyed to achieve a wide spectrum of hues. The fiber’s luster, or sheen, varies depending on factors such as fiber length and processing techniques.
Chemical Properties of Cotton Fiber:
- Effect of bleaches – Cotton has resistance to bleach. H2O2, NaOcl, etc used as bleaching agents.
- Effect of Acids & Alkalis- cotton is dissolved in highly concentrated mineral acids but highly resistant to alkalis.
- Effect of organic solvents- Cotton has high resistance to most organic solvents such as dry cleaning agents.
- Effect of sunlight- When cotton is exposed to sunlight, its strength is gradually lost and the fiber turns yellow.
- Effect of insects – Cotton is not attacked by beetles.
- Effect of micro-organisms- Cotton is attacked by fungi and bacteria.
a. Composition of Cotton Fiber
Cotton fiber comprises approximately 90% cellulose, along with trace amounts of waxes, proteins, and other organic compounds. This composition contributes to its strength and absorbency.
b. Reaction with Acids and Bases
Cotton fibers are relatively inert and exhibit minimal reactivity with acids and bases. However, prolonged exposure to acidic or alkaline environments can degrade the fiber’s structure over time.
c. Resistance to Chemicals
Cotton is generally resistant to most chemicals, making it suitable for applications where exposure to solvents or cleaning agents is common. However, certain harsh chemicals can cause deterioration or discoloration.
Chemical Composition of Cotton Fiber:
- Cellulose – 80 – 90%
- Water – 6 -8 %
- Oil and Wax – 0.5 – 1 %
- Pectin and coloring mats – 0- 1.5%
- Mineral Materials – 1 – 1.8 %
- Ash – 0 – 1%
Absorbency and Moisture Content
a. Ability to Absorb Moisture
One of cotton’s most remarkable properties is its ability to absorb moisture. It is ideal for clothing and textiles. Cotton fibers can absorb up to 27 times their weight in water, providing comfort and breathability.
b. Impact of Moisture on Properties
Excessive dampness can lead to shrinkage and mildew growth. Proper care and storage are essential to maintain cotton fabric’s integrity.
Thermal Properties
a. Heat Resistance
Cotton fibers exhibit excellent heat resistance. It makes them suitable for high-temperature applications such as ironing and sterilization. However, prolonged exposure to heat can cause yellowing or degradation.
b. Flammability
Although cotton is not inherently flame-retardant, it is less prone to ignition compared to synthetic fibers. Cotton fabrics tend to char rather than melt, reducing the risk of severe burns.
Electrical Properties
a. Conductivity
Cotton fibers are poor conductors of electricity due to their organic composition and insulating properties. This makes cotton fabrics safe for use in environments where static electricity poses a risk.
b. Insulation
The natural insulation provided by cotton fibers makes them ideal for thermal and sound insulation applications. Cotton-based materials help regulate temperature and reduce energy consumption.
Biological Properties
a. Resistance to Pests and Microorganisms
Cotton fibers possess inherent resistance to pests such as moths and beetles, reducing the need for chemical treatments in storage and processing. Additionally, cotton’s antimicrobial properties inhibit microbial growth, enhancing hygiene.
b. Biodegradability
Unlike synthetic fibers obtained from petroleum-based sources, cotton is biodegradable and environmentally friendly. Cotton products decompose naturally, minimizing their impact on landfills and ecosystems.
Conclusion
Cotton fiber’s physical and chemical properties make it a versatile and valuable material in numerous applications. From its softness and absorbency to its strength and biodegradability, cotton continues to play a vital role in diverse textile industries while evolving to meet changing consumer demands.
Mahedi Hasan is a Textile Engineer, as well as a Top Rated content writer at Upwork, a Level 02 Seller at Fiverr, Level 02 Publisher at Ezoic. A passionate textile and fashion content writer, fashion SEO expert, and fashion web designer. Having a B.Sc. in Textile Engineering Degree from Textile Engineering College, Noakhali (TECN). The department is Apparel Engineering. Highly Experienced fashion writer for the last 3+ years. Have extensive 7 years of experience in the wholesale clothing business.