Importance and Classification of Textile Fibers

Fibers are incredibly important in textile production. Not all fibers are suitable for creating textiles; textile fibers have specific properties that enable them to be spun into yarn or directly made into fabric. They need to be strong, flexible, elastic, and durable. Textile fibers must be at least five millimeters in length; shorter fibers cannot be spun together. For instance, cotton fibers are strong and pliant enough to be spun into yarn, making them ideal for textiles. Conversely, fibers like those in corn cobs are too weak to be used in textile production.

A fiber is a linear strand characterized by its flexibility and length, which is significantly greater than its width. This property distinguishes fibers from other forms such as tapes, films, and rods. For designers, fibers and filaments represent the fundamental building blocks of textile construction. In this article, I will delve into the various types of textile fibers and their classification.

The Evolution and Application of Textile Fibers

The application of fibers in textiles and clothing dates back to the early stages of human evolution. Initially, clothing was not for aesthetic purposes but for protection against elements like cold, heat, rain, and dust. The use of fibers in clothing can be traced back to 5000–4500 BC with the utilization of hemp, flax, cotton, and silk, along with the advent of sericulture. Before the Industrial Revolution, all fiber sources were natural.

During the 18th and 19th centuries, the Industrial Revolution brought significant advancements, including machinery for fiber processing and applications. This period also saw the introduction of regenerated fibers like rayon and later synthetic fibers like nylon and polyester, which reduced the dominance of natural fibers and spurred competition for developing new and unique fibers.

The emergence of regenerated and synthetic fibers added a new dimension to research and development in the field of textiles. This led to the strong belief that fibers can be developed, manufactured, or regenerated from any material, provided the chemical behavior, structural alignment, molecular properties, and processing conditions are analyzed and controlled. Consequently, a wide range of fibers and materials can be developed.

Textile fiber is the fundamental raw material used to produce various types of finished textile products. A fiber that can be spun into yarn or processed into textiles, such as woven fabric, knit fabric, lace, felt, or non-woven fabric, through appropriate interlacing methods is known as a textile fiber.

Classification of Textile Fibers

Textile fibers are classified into the following main categories:

1. Natural Fibers
2. Man-Made Fibers
3. Regenerated Fibers

Textile fibers can be broadly classified into two main types: Natural fibers and Synthetic fibers (also known as man-made or artificial fibers). However, textile fibers can also be categorized in several other ways:

1. Classification Based on Sources
2. Classification Based on Polymer Type
3. Classification by Botanical, Zoological, or Chemical Name
4. Classification by Utility
5. Classification by Thermoplasticity
6. Classification by Ability to Absorb Moisture

Each classification method provides a different perspective on the properties and applications of textile fibers.

Natural Fibers

Natural fibers occur in nature and are traditionally categorized as:

• Vegetable Fibers: Found on seeds (e.g., cotton), in the phloem (e.g., flax, hemp, jute), or from stems/leaves (e.g., manila hemp, sisal).
• Animal Fibers: Protein-based fibers harvested from animals (e.g., wool, rabbit hair, camel hair, goat hair, yak hair) or from cocoons (e.g., silk, spider silk).
• Mineral Fibers: The only natural mineral fiber is asbestos, obtained from certain rocks.

Man-Made Fibers

Synthetic fibers are produced through chemical processes and include:

• Polyester
• Nylon
• Acrylic
• Polypropylene
• Elastin
• Polyvinyl Chloride
• Polyurethane

Regenerated Fibers

These fibers are regenerated from natural materials using chemical processes. Examples include:

• Rayon
• Bamboo Fibers
• Modal
• Lyocell

Classification of Textile Fibers Based on Sources

Classification of textile fibers based on sources categorizes fibers according to their origins. This approach distinguishes fibers derived from natural sources from those that are man-made. Figure 2 illustrates this classification concept.

Natural fibers are derived from vegetable and animal sources, and there are approximately 15 significant natural fibers used in processing and converting into fabrics. Here are some of the major natural fibers:

• Cotton
• Flax
• Hemp
• Jute
• Ramie
• Silk
• Wool
• Cashmere
• Mohair
• Alpaca
• Angora
• Camel Hair
• Yak Hair
• Coir
• Sisal

Each of these fibers has unique properties that make them suitable for various textile applications.

Major Vegetable-Based Textile Fibers

Vegetable sources contribute significantly to the production of natural fibers used in textiles. Here are the key fibers derived from vegetable sources:

1. Cotton
   • Cotton, consisting of pure cellulose, is the most widely utilized natural fiber.
   • It is produced primarily in China, Brazil, India, Pakistan, the USA, and Uzbekistan.
2. Flax
   • Flax, a lignocellulosic bast fiber, is predominantly found in the European Union.
   • This fiber is mainly used to produce linen.
3. Hemp
   • Hemp is a bast fiber with low lignin content.
   • China is the leading producer of hemp fiber.
4. Jute
   • Jute, known for its strength, is a lignocellulosic fiber mainly grown in India and Bangladesh.
5. Ramie
   • Ramie, also known as China grass, is a bast fiber with a silky luster and good elasticity.
   • It is primarily found in China and Brazil.
6. Sisal
   • Sisal is a coarse, hard leaf fiber commonly grown in Brazil, Tanzania, and Kenya.
7. Abaca
   • Abaca, or Manila hemp, is a leaf fiber obtained from the leaf sheath of Musa textiles.
   • The Philippines is the major producer, and the fiber contains about 15% lignin.
8. Coir
   • Coir is a short, coarse fiber extracted from coconut shells.
   • Predominantly found in India, Sri Lanka, the Philippines, Vietnam, Indonesia, and Brazil.
   • Coir has a high lignin content, making it strong but less flexible.

Major Animal-Based Textile Fibers

Animal sources provide several significant natural fibers used in textile production. Here are the key fibers derived from animal sources:

1. Alpaca
   • Alpaca fiber, similar to wool, comes from the Lama Pocos.
   • It is available in approximately 22 natural colors.
   • Major producers include Peru, North America, Australia, and New Zealand.
   • Alpaca fiber is stronger than wool.
2. Angora
   • Angora fiber is obtained from rabbits and is known for being very soft, fine, and silky.
   • China produces 90% of the world’s Angora fiber.
   • Angora fabric is ideal for thermal clothing.
3. Camel Hair
   • Camel hair is sourced from the two-humped Bactrian camel, primarily found among nomadic households in Mongolia and Inner Mongolia, China.
   • It is the softest and most premium hair fiber.
4. Cashmere
   • Cashmere fiber comes from Kashmir goats.
   • It is produced in China, Australia, India, Pakistan, New Zealand, Turkey, and the USA.
   • This fiber is known for being luxurious and expensive.
5. Mohair
   • Mohair fiber is derived from Angora goats and is primarily produced in South Africa.
   • It is characterized by its smooth and lustrous quality.
6. Silk
   • Silk is a natural filament fiber with high luster.
   • It is mainly produced in China, Brazil, India, Thailand, and Vietnam.
7. Wool
   • Wool is the most important protein fiber and was the first domesticated fiber.
   • Major producers include Australia, New Zealand, China, Iran, Argentina, and the UK.

Ground and Petrochemical-Based Textile Fibers

In addition to fibers collected from sources above ground, there are also fibers sourced from below ground, such as metals. Since World War II, there has been a significant push to produce synthetic materials, primarily derived from petrochemicals. These manufactured fibers are termed synthetic fibers because their raw materials are synthesized, followed by polymerization and fiber formation.

The development and utilization of petrochemicals have led to the significant growth of synthetic fibers. This remarkable progress in the petrochemical industry has driven the expansion of both the synthetic fiber industry and the polymer industry. Synthetic fibers have become a major component of modern textiles due to this industrial advancement.

Understanding Polymer-Based Classification of Textile Fibers

Polymer-based classification categorizes textile fibers by their construction from smaller molecules forming larger ones. Polymers, deriving from Greek roots meaning “many parts,” distinguish themselves by their repetitive molecular subunits. These materials, known interchangeably as macromolecules, high polymers, or giant molecules, feature high molecular weights and span organic, inorganic, or organometallic origins. They serve crucial roles across industries like adhesives, building materials, paper, clothing, fibers, coatings, plastics, ceramics, concrete, liquid crystals, photoresists, and coatings due to their versatility and widespread applicability.

Understanding Polymeric Materials in Fibers

Polymeric materials in fibers can be categorized into natural or synthetic, and organic or inorganic compositions. Organic polymers contain carbon atoms in their main chain, distinguishing them from inorganic polymers. Carbochain polymers consist entirely of carbon atoms, while heterochain polymers incorporate other atoms alongside carbon.

Natural inorganic polymers include substances like sand, asbestos, agates, feldspars, mica, quartz, and talc. Natural organic polymers encompass polysaccharides (e.g., starch, cellulose), nucleic acids, lignin, rubber, and proteins. Synthetic inorganic polymers include boron nitride, concrete, high-temperature superconductors, and various glasses. Synthetic organic polymers comprise fibers, plastics, and coatings such as polyethylene, polypropylene, polyamides, polyesters, vinyl polymers, polyurethanes, and synthetic rubbers.

Fibers are polymeric materials known for their strength in one direction, typically having a length (l) significantly greater than their diameter (d) (l/d ratio > 100). Elastomers or rubbers are polymeric materials that can deform under force and return to their original shape when the force is removed. Plastics exhibit properties between fibers and elastomers, being both hard and flexible.

Both natural and synthetic fibers derive from natural high molecular weight polymeric substances, highlighting their polymeric nature.

Classification of Textile Fibers by Botanical, Zoological, or Chemical Name

Textile fibers can be classified according to their botanical, zoological, or chemical origins:

1. Botanical Classification (Vegetable Fibers):
   • Cotton, jute, flax, and others fall under this category.
   • These fibers are derived from plants and are classified based on their botanical sources.
2. Zoological Classification (Animal Fibers):
   • Wool, silk, and other hair fibers are categorized under zoological classification.
   • These fibers are sourced from animals and categorized based on their zoological origins.
3. Chemical Classification (Man-made Fibers):
   • Fibers under this category are classified by their chemical composition and manufacturing process.
   • Examples include regenerated cellulose and polyamide linear macromolecules, characterized by their recurring functional groups and chemical structures.

Each classification provides insights into the origins and properties of textile fibers, highlighting their diverse applications in various industries.

Classification of Textile Fibers by Utility

Textile fibers are classified based on their utility, categorized into two main types:

1. Major Textile Fibers:
   • Cotton, wool, silk, jute, rayon, viscose rayon, acetate rayon, nylon, polyester, and others fall under this category.
   • These fibers are extensively used by the textile industry for various textile applications.
2. Minor Textile Fibers:
   • Banana fiber, abaca fibers, asbestos fibers, bamboo fiber, soybean fibers, pineapple leaf fiber, metallic fiber, milk for casein fiber, alginate fibers, rubber, and others are categorized as minor textile fibers.
   • These fibers are used to a much lesser extent in textile applications compared to major fibers.

Classification of Textile Fibers by Thermoplasticity

Textile fibers can be classified based on their thermoplastic properties into two main types:

1. Thermoplastic Type:
   • These fibers can be deformed by heat and pressure without undergoing chemical changes.
   • Thermoplastic fibers soften when exposed to heat, allowing them to be molded and heat-set.
   • Examples include most synthetic fibers like polyamide, polyester, regenerated acetate rayon, and polyvinyl chloride (PVC) fibers, which exhibit varying degrees of thermoplasticity.
2. Non-thermoplastic Type:
   • Fibers in this category do not soften or deform under heat and pressure without undergoing chemical changes.
   • They lack the ability to be molded or heat-set.
   • Examples of non-thermoplastic fibers include certain natural fibers and specialty fibers that retain their structure when exposed to heat.

Classification of Textile Fibers by Their Ability to Absorb Moisture

Textile fibers can be classified based on their ability to absorb moisture into two main categories:

1. Hygroscopic or Hydrophilic Fibers:
   • These fibers are characterized by their ability to absorb moisture.
   • They contain hydrophilic groups in their molecules that attract water.
   • Examples include all natural fibers such as cotton, wool, silk, and others.
   • Hydrophilic fibers have higher moisture absorption compared to hydrophobic fibers, which facilitates processes like bleaching, mercerization, dyeing, and applying different finishes using chemicals.
2. Hydrophobic Fibers:
   • These fibers do not readily absorb moisture.
   • They contain very few water-attracting groups, typical of synthetic fibers.
   • Examples include polyester, nylon, polypropylene, and other synthetic fibers.
   • Low moisture absorption in hydrophobic fibers makes them challenging to dye and bleach.
   • They are also prone to developing static electricity charges more quickly than hydrophilic fibers, which can complicate mechanical processing.

Essential Properties of Textile Fibers

Textile fibers must possess certain properties:

• Length and Breadth Variation: The length-to-breadth ratio of fibers should be more than 1000:1.
• Strength: This includes tensile, bending, and bursting strength. Stronger fibers result in stronger yarns and fabrics.
• Uniformity: Uniform fibers produce even yarns, contributing to the strength of the resulting fabric.
• Spinability: This property allows fibers to be twisted into yarn.
• Fineness: Finer fibers result in stronger yarns due to increased surface area and inter-fiber friction.
• Luster: Natural luster enhances the value of fibers, especially in natural fibers like silk.
• Durability: Textile fibers should withstand processing treatments and resist physical, chemical, and bacteriological attacks.

Summary of Textile Fibers and Their Classification

Definition and Importance:

• A fiber is a flexible, linear strand much longer than its width, unlike tapes, films, and rods.
• Fibers and filaments are fundamental elements in textile construction.

Historical Context:

• Use of fibers in textiles dates back to 5000–4500 BC with natural fibers like hemp, flax, cotton, and silk.
• The Industrial Revolution introduced machinery for fiber processing and synthetic fibers like nylon and polyester, reducing reliance on natural fibers and spurring innovation.

Textile Fiber Definition:

• A textile fiber can be spun into yarn or processed into fabrics using interlacing methods.

Classification of Textile Fibers:

1. Based on Sources:
   • Natural Fibers:
     • Vegetable Sources: Cotton, flax, hemp, jute, ramie, sisal, abaca, and coir.
     • Animal Sources: Alpaca, angora, camel hair, cashmere, mohair, silk, and wool.
   • Synthetic Fibers: Derived from petrochemicals, developed post-World War II, including materials like nylon and polyester.
2. Based on Polymer:
   • Polymers, whether natural or synthetic, are made of repeating molecular subunits.
   • Natural polymers include cellulose, proteins, and rubber.
   • Synthetic polymers include materials like polyethylene, polypropylene, and polyamides.
3. Botanical, Zoological, or Chemical Name:
   • Botanical: Vegetable fibers like cotton and flax.
   • Zoological: Animal fibers like wool and silk.
   • Chemical: Synthetic fibers based on chemical composition, e.g., polyamide.
4. Utility:
   • Major Textile Fibers: Widely used, e.g., cotton, wool, silk, nylon.
   • Minor Textile Fibers: Less commonly used, e.g., banana fiber, asbestos fibers.
5. Thermoplasticity:
   • Thermoplastic Fibers: Can be softened and molded by heat, e.g., polyester.
   • Non-Thermoplastic Fibers: Cannot be deformed by heat without chemical changes.
6. Moisture Absorption:
   • Hydrophilic Fibers: Absorb moisture, e.g., natural fibers.
   • Hydrophobic Fibers: Do not absorb moisture easily, e.g., synthetic fibers.

This classification system helps in understanding the diverse properties and applications of different textile fibers.

Frequently Asked Questions (FAQs) about Textile Fibers

1. What is a textile fiber?
   • A textile fiber is a flexible, linear strand much longer than its width, used as the basic raw material for producing various types of textile products like woven fabrics, knit fabrics, lace, felt, and non-wovens.
2. How are textile fibers classified?
   • Textile fibers can be classified based on their sources (natural or synthetic), polymer composition, botanical/zoological/chemical names, utility, thermoplasticity, and moisture absorption properties.
3. What are natural fibers, and where do they come from?
   • Natural fibers are obtained from plant, animal, or mineral sources. Examples include cotton and flax (plant-based), wool and silk (animal-based), and asbestos (mineral-based).
4. What are synthetic fibers, and how are they produced?
   • Synthetic fibers are man-made fibers produced from petrochemicals through processes like polymerization. Examples include nylon, polyester, and acrylic.
5. What are the key differences between hydrophilic and hydrophobic fibers?
   • Hydrophilic fibers absorb moisture readily, making them suitable for processes like dyeing and finishing (e.g., cotton and wool). Hydrophobic fibers resist moisture absorption, making them less prone to staining but harder to dye (e.g., polyester and nylon).
6. What is thermoplasticity in textile fibers?
   • Thermoplasticity refers to the ability of a fiber to be deformed and set into new shapes with the application of heat. Thermoplastic fibers can be molded and heat-set, unlike non-thermoplastic fibers.
7. Why are synthetic fibers significant in the textile industry?
   • Synthetic fibers offer unique properties such as high strength, elasticity, resistance to shrinking, and quick drying, making them valuable for various applications and reducing the reliance on natural fibers.
8. How did the Industrial Revolution impact the textile fiber industry?
   • The Industrial Revolution introduced machinery for fiber processing and led to the development of synthetic fibers, which diversified the types of available fibers and enhanced textile production efficiency.
9. What are some examples of fibers from vegetable sources?
   • Examples include cotton, flax, hemp, jute, ramie, sisal, and abaca. These fibers are primarily composed of cellulose and are used in various textile applications.
10. What are the primary applications of textile fibers?
    • Textile fibers are used to produce a wide range of products, including clothing, home textiles, industrial fabrics, and technical textiles. They provide essential properties like durability, comfort, aesthetics, and functionality.