Classification of Textile Fibres: Natural, Regenerated, Synthetic, and Inorganic Types Explained with Examples

Introduction: Why Understanding Fibre Classification Is Essential

Have you ever asked yourself why does cotton feel soft, nylon tough and silk have a shiny finish on them? The secret is in where the fibres have come (originated) and how they are structured as regards to their molecular aspects.

It is not merely hypothetical, but technically essential in the case of every person, who takes a career or educational option in the area of textiles; in whether you are a student, a researcher, a mill technician, or a candidate taking an exam at the end of the day, may be a very good option to know.

Generally, the textile fibres could be categorized into manufactured and natural fibres. These are categorized by way of origin, composition and mode of production. All different fibres possess existent characteristics, applications, and processing needs of the same fibre-on the other hand affecting yarn quality, dyeability, comfort, performance, and end use-worthiness.

So, we will take a systematized, but approachable look at this fibre world: natural fibres, regenerated fibres, synthetic fibres, inorganic fibres, and, finally, some less-common ones, and some real-life examples about the fibre world and what they mean to the industries.

Natural Fibres

Natural fibres are the ones derived in a direct way of the nature, that is, whether of a plant, animal or mineral. These fibres are renewable and biodegradable and have existed being used as textile products throughout the centuries.

A. Plant-Based Natural Fibres (Cellulose Fibres)

The plant fibres mainly used are composed of cellulose that is a carbohydrate polymer and is held in the walls of the plant cells. These fibres are subdivided according to the part of a plant where they are obtained.

1. Seed Fibres

The fibres are grown out of plant seeds. Cotton is the most common seed fibre spun into yarn to make anything including T shirts and bedsheets.

• Cotton: Cotton is the strongest fibre and can be spun forcefully, it is breathable and can have colour easily added to it, this is why cotton is the mainstay of worldwide textile industry. (source)
• Kapok: Kapok is too hollow and does not have a binding force needed to spin. It is mostly applied in the stuffing of life vests, pillows and mattresses.

2. Bast or Stem Fibres

These are taken out of the inner bark or phloem of stems of plants.

• Flax: Flax fibres which are strong, lustrous and absorbent in nature and turned into linen.
• Jute: Jute is normally used in packaging, carpets and upholstery because it has a coarse texture.
• Hemp and Ramie: It is said to be strong and durable. Hemp is being noticed in terms of sustainable textile and ramie is applied in home furnishings and mixed clothing.

3. Leaf Fibres

Technical and household products These fibres are coarse and stiff compared to the seed or bast fibres and thus they are used in technical and household products.

• Sisal: Sisal is used to make ropes, mats and agro-textiles.
• Abaca: Abaca is generally paper and marine cordage.
• Pineapple fibre - PinA: This is what has been traditionally used in the Philippines in fine dressy clothes but it is niche and still made by hand.

4. Fruit Fibres

These are derived out of outer covers of fruits.

• Coir: This fibre is also called coir and is made out of coconut husk; it is thick, coarse and salt water resistant. They suit well as door mats, brushes and floor coverings.

B. Natural Fibres Animals (Protein Fibers)

Protein polymers found in animal fibres are mainly keratin (wool and hair) and fibroin (silk). These are traditions that are appreciated due to their springiness, warmness, durability, and heat insulation.

1. Hair Fibres

Such fibres are derived out of the hair or fleece on mammals.

• Wool (sheep): Wool Curls and is great insulation and stretchy. It is able to keep warm even in the wetness.
• Alpaca, Camel, Cashmere: These are extravagant fibres and are tender and delicate compared to wool of sheep and are manufactured in top winter clothing. They are different in thermal, tactile, aesthetic characteristics of each type.

2. Secretion Fibres

These are obtained from the secretions of insects.

• Silk: The only natural filament fibre, silk is secreted by silkworms during cocoon formation. It is soft, strong, lustrous, and biodegradable. Despite its delicate appearance, silk’s tensile strength is comparable to that of steel (gram for gram).

C. Mineral-Based Natural Fibres

Though less common, mineral-based fibres were historically used in textiles.

• Asbestos: A natural mineral fibre that was valued for its heat resistance. However, it is no longer used in textiles due to its proven carcinogenic effects when inhaled.

Summary of Natural Fibres:

Natural fibres are environmental friendly, have good ventilation and are comfortable. They can also decay biologically, take up moisture readily and are usually well dyeable. Nevertheless, they might not have dimensional stability, chemical resistance and durability which is found in modern synthetic fibres.

Manufactured Fibres

Man made fibres are not extracted by the effortless means and are not as such obtained in useable state. They are in fact made through industrial means where they process raw materials either natural polymers or synthetic chemicals and modify them into fibres. The fibres are adjustable to a performance requirement, e.g., elastic, wrinkle-free, flame resistant, or moisture-wicking.

The fibres manufactured in the most general divisions include:

• Regenerated fibres - obtained as a result of natural raw materials yet chemically treated
• Man made fibres- these are completely synthetic polymers
• Inorganic fibres - non-organic fibres intended to be used industrially and technically

A. Chemically Processed Natural Polymer Regenerated Fibres

These fibres are produced by degrading natural products, be it cellulose or proteins, and by reorganizing them into filaments by the means of spinning. They are unnatural but still have some features of natural source.

1. Regenerated Fibres and Cellulosic Regenerated Fibres

• Viscose Rayon: Viscose is absorbent, breathable and soft and is made out of wood pulp or cotton linters. It is just like imitating the texture of cotton or silk and it is greatly used when it comes to ladies attire, lining and furnishing.
• Modal and Lyocell: These are newer, improved forms of regenerated cellulose which have superior dimensional stability, more environmental-friendly manufacturing (especially Lyocell, the use of solvents is closed-looped). Unlike the conventional viscose, Lyocell is also more long-lasting and a resistant to wrinkles. (source)

2. Modified Cellulosic Fibres

• Acetate and Triacetate: These are also produced through chemically altering cellulose with acetic acid derivatives. Such fibres are smooth, shiny and have a good drape. Acetate is frequently applied in formal clothes, liners and high end materials that need sheen and form.

Regenerated fibres are biodegradable yet they are vulnerable to extreme heat and would shrink unless they are subjected to chemicals.

B. Synthetic fibres (Man-Made entirely of petrochemicals)

Such fibres are produced by the polymerisation of chemicals (usually petroleum based chemicals). They have greater mechanical strength, durability and they are less likely to absorb moisture rendering them suitable in technical, industrial and high performance situations.

Let’s look at the main synthetic fibre groups.

1. Polyamides

• Nylon 6 and Nylon 66: One of the early synthetic fibres to be commercialised, nylons are elastic, abrasion resistant and strong. They are widely used in hosiery, seat belts, parachutes, engineered composites and ropes.
• Kevlar (TM): It has the extreme tensile strength and excellent thermo stabilization that is a high performance polyamide. It is applied to bulletproof vest, aerospace parts and protective equipment.

2. Polyesters

• Polyethylene Terephthalate (PET): It is the most popular synthetic fibre in the globe. PET fibres are highly multipurpose, long lasting, dries fast and do not shrink and wrinkle. They are applied in clothing and home furnishing, nonwoven, and industrial products.
• Polybutylene Terephthalate (PBT): Has enhanced stretch recovery in comparison with PET and utilised in swimwear, sportswear and automotive textile industry.

3. Polyacrylonitrile (Acrylic)

• Acrylic fibres: Highly light, warm and by softer than wool, acrylics have become a common replacement of wool in places where it is used on sweaters, blankets, and knits. They are moth, chemical and sun-proof, but they can pill with time.

4. Polyolefins

• Polypropylene (PP): These fibres are light weight, chemical resistant fibres and non-absorbent. Polypropylene is more commonly found in plain textile to be discarded (such as nonwoven medical fabric), geotextile, and performance garments.

5. Polyurethanes

• Spandex (Lycra or elastane): referred to its high/ extreme stretch, bounce back capability. It has always been utilized in mixtures to deliver relaxation stretch to sportswear, intimate apparel and performance clothing.

6. Vinyl-Based Fibres

• Polyvinyl Alcohol (PVA): This material is not in the mainstream use in textile but is utilized in high-technical textile, packaging film and even some eco-friendly usages, because of its property of being soluble in water.

Most synthetic fibres are generally not biodegradable, though they have a long life and easily resist wear, and thus are very usable in commercial as well as technical fabrics.

C. Inorganic Fibres (Non-Organic, High-Performance Materials)

Inorganic fibres are fibres that are made of the non-carbon based materials and they are mainly used in technical, industrial applications and functional applications which are in places of high temperatures. They are not worn as clothing but play an important role in such fields as filtration or reinforcement and insulation.

1. Glass Fibres

These fibres are extruded molten glass in spinnerets and are not combustible, stable and are ideal in thermal and electrical insulation. They find application in composites, electronics and filtration media.

2. Ceramic Fibres

The strength of these is good in terms of thermal stability and corrosion. The ceramic fibres serve as furnace lining, thermal defence product, and aerospace insulating materials.

3. Metallic Fibres

These are Lurex (metallic yarns) and stainless steel fibres. They find their application during decorative fabrics, electromagnetic shielding textiles as well as heat resistant textiles (scale back industrial gloves or protective clothing).

Summary of Manufactured Fibres

In contrast to natural fibres, manufactured fibres can now be formulated on a very specific performance basis e.g. high moisture control, UV-resistance, high strength, elastic and fire-retardant. Most synthetics are however hydrophobic and not breathable unless modified specially.

Knowing their polymer type, how they are made and their usage can be useful in choosing the appropriate fiber to the appropriate product: fashion, function or future-tech.

Related post:

• Essential Properties of Textile Fibres
• Polymerisation in Nylon 6 and Nylon 66: Explained Simply
• Lyocell Fibre: The Future of Sustainable Textiles
• Cotton Fibre Structure and Processing Behaviour

FAQ Section

Q1: What is the difference between natural and synthetic textile fibres?

Natural fibres come from plants or animals and are biodegradable, while synthetic fibres are man-made from petrochemicals and offer high strength, durability, and resistance to environmental factors.

Q2: Why is silk considered a filament fibre?

Silk is the only natural fibre that occurs in filament form, meaning it is naturally long and continuous, unlike most other natural fibres which are short staple fibres.

Q3: Which fibres are best for high-temperature applications?

Inorganic fibres like glass, ceramic, and metallic fibres are preferred in high-temperature technical applications due to their thermal stability and non-flammable properties.

Q4: Are regenerated fibres natural or synthetic?

Regenerated fibres like viscose or lyocell are produced from natural raw materials like wood pulp but undergo chemical processing. So, they are classified as man-made but retain many natural fibre properties.