Types, Characteristics, Production and Application of Nylon Fibre

What is Nylon Fibre?
Nylon is a man-made synthetic polymer, polyamide filament or staple fibre. It is a long-chain synthetic polyamide in which less then 85% of amide linkages are attached to two aromatic rings. Nylon fibres are made up of linear macromolecules whose structural units are linked by the amide (–NH–CO–) group. Therefore, these fibres are termed as the polyamides. The nylon fibres are produced by the extrusion of molten polymer and no solvents are involved.

Nylon was developed by DuPont in the 1930s, and it came to market in 1938. Allegedly, the name is derived from the letters of the cities that the chemists responsible for its creation came from: New York and London. Nylon is now known by a more generic name, polyamide, because it is made out of amide chemicals. Polyamides are available in many forms, including compliant textiles and rigid, resistant materials. Nylon is one of the most common polymers used as a fibre. There are several forms of nylon depending upon chemical synthesis such as nylon 4, 6, 6.6, 6.10, 6.12, 8, 10, 11through to 88 etc; the number is determined by the number of carbon atoms per molecule. The most important types are- Nylon 6 and Nylon 6,6.

Nylon is produced in both regular and high tenacity strengths. Although it is one of the lightest textile fibres, it is also one of the strongest. The strength of nylon will not deteriorate with age. It has the highest resistance to abrasion of any fibre. It can take a tremendous amount of rubbing, scraping, bending, and twisting without breaking down.

Nylon is one of the elastic fibres, however, such stretch nylon yarns as Helanca and Agilon have exceptional elasticity. It has excellent resilience and draping qualities. Nylon does not absorb much moisture, therefore the nylon fabric feels clammy and uncomfortable in warm, humid weather.

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Nylon fibers are commonly used in the manufacture of clothing, upholstery, carpets, and industrial materials, as well as in the production of various types of plastic products. They are also used in the production of fishing line, ropes, and other types of cordage, due to their high strength and flexibility.

Types of Nylon Fibre:
There are several types of nylon fibres, each with different properties and characteristics. Here are some of the most common types of nylon fibre:

1. Nylon 6: This type of nylon is made from a single monomer, caprolactam. It has a high melting point and good abrasion resistance.
2. Nylon 6,6: Nylon 6,6 is made from two monomers, hexamethylenediamine and adipic acid. It has a higher melting point than Nylon 6 and is stronger and more rigid.
3. Nylon 4,6: This type of nylon is made from two different monomers, butadiene and adipic acid. It is known for its high heat resistance, as well as its strength and durability.
4. Nylon 11: It is made from a renewable resource, castor oil. It is known for its flexibility, chemical resistance, and low moisture absorption, and is often used in the production of tubing and other types of fluid transfer systems.
5. Nylon 12: Nylon 12 is made from laurolactam, and is known for its low moisture absorption and excellent chemical resistance. It is commonly used in the production of tubing, wire coatings, and other types of industrial components.
6. Bio-based Nylon: It’s a type of nylon fibre that is made from renewable resources such as castor oil, corn, or sugarcane. It is an eco-friendly alternative to traditional nylon fibres, and is commonly used in the production of clothing, automotive parts, and other industrial applications.

Properties / Characteristics of Nylon Fibre:
Nylon fibre has several common properties that make it a popular material for various applications. Some of the key properties of nylon fibre include:

a) High strength: Nylon fibres are known for their high strength and excellent resistance to wear and tear. This makes them ideal for use in heavy-duty applications such as automotive and industrial equipment.

b) Lightweight: This fibre is relatively lightweight, making them easy to handle and use in a variety of applications.

c) Durability: They are resistant to abrasion, chemicals, and UV radiation, making them a durable choice for applications that require long-term performance.

d) Flexibility: Nylon fibres have good flexibility and can be easily molded into various shapes and forms. This makes them suitable for use in a wide range of applications, including textiles, carpets, and composites.

e) Moisture resistance: Nylon fibre is hydrophobic and do not absorb moisture, making them an ideal choice for applications that require resistance to water and moisture.

f) High melting point: It has a high melting point, which makes them suitable for use in high-temperature applications.

g) Good dyeability: Nylon fibres can be easily dyed to achieve a wide range of colors, making them popular in the textile industry.

h) Versatility: Nylon can be produced in a range of different forms, including yarns, fabrics, films, and molded parts. This makes it a versatile material that can be used in a wide range of applications, from clothing and upholstery to industrial components and automotive parts.

Physical Properties of Nylon Fibre:

Chemical Properties of Nylon Fibre:

(i) Effect of acids: Less resistant to acids than to alkalies. Acid causes hydrolysis of amide groups, reducing or lose of affectiveness of inter-polymer Hbonding and thus weakening nylon.

(ii) Effect of alkalies: Prolonged exposure to alkalies will cause significant alkali hydrolysis of nylon polymer thereby resulting in weakening 1:he nylon. It has highly resistant to micro-organism and has high abrasion resistance.

Nylon Fibre Production Flow Chart:
Process flow chart of nylon fibre manufacturing is given below:

Raw Materials

↓

Polymerization

↓

Solidification

↓

Pelletization

↓

Melt Spinning

↓

Quenching

↓

Drawing

↓

Heat Setting

↓

Texturing

↓

Finishing

↓

Cutting

↓

Packing

↓

Shipping

Above steps are briefly described below:

1. Raw Materials: Adipic acid and hexamethylene diamine are the two main raw materials required for the production of nylon fibre.

2. Polymerization: Adipic acid and hexamethylene diamine are reacted together under heat and pressure to form nylon resin.

3. Solidification: The liquid nylon resin is cooled and solidified.

4. Pelletization: Solidified nylon resin is broken into small pellets.

5. Melt Spinning: The pellets are melted and extruded through spinnerets to form continuous filaments.

6. Quenching: Filaments are cooled rapidly in water to solidify them.

7. Drawing: The solidified filaments are stretched to orient the molecules and increase strength.

8. Heat Setting: Stretched filaments are heated to set the orientation and prevent shrinkage.

9. Texturing: The heat-set fibres may undergo a texturing process to create a desired texture or appearance.

10. Finishing: Nylon fibres are finished with various treatments to improve their performance and appearance, such as lubrication, dyeing, or flame retardant coatings.

11. Cutting: The continuous fibres are cut into shorter lengths.

12. Packing: Nylon fibres are packed into bales or boxes.

13. Shipping: Packed nylon fibres are shipped to customers for use in a wide range of applications.

Uses / Application of Nylon Fibre:
Nylon fibre is a versatile material that can be used in many different textile and clothing applications due to its strength, durability, and moisture-wicking properties.

• Athletic wear, including leggings, shorts, sports bras, and workout tops
• Hosiery, including stockings, pantyhose, and socks
• Swimwear, including swimsuits and swim trunks
• Jackets and outerwear, including raincoats and windbreakers
• Lingerie, including bras, panties, and shapewear
• Undergarments, including men’s underwear and undershirts
• Blouses, shirts, and tops, including dress shirts and casual shirts
• Dresses and skirts, including formal gowns and casual dresses
• Pants and trousers, including dress pants and casual pants
• Upholstery fabrics for furniture and other household items, including couches and chairs
• Accessories such as hats, scarves, gloves, and belts
• Sleeping bags and outdoor gear, including tents and backpacks
• Automotive textiles, including car seats and headliners
• Military uniforms and gear, including uniforms and backpacks
• Medical textiles, including bandages and surgical gowns

Nylon fibre not only uses in clothing but also uses in different sectors. Here are some examples:

• Carpeting and rugs.
• Industrial applications, including automotive parts, conveyor belts, ropes, and hoses.
• Packaging materials, such as film and bags.
• Fishing nets.
• Toothbrush bristles.
• Musical instrument strings.
• Electrical insulation materials.
• 3D printing.

References:

1. Fibres to Fabrics by Bev Ashford
2. Textile Raw Materials By Ajay Jindal and Rakesh Jindal
3. Textile Engineering – An Introduction Edited by Yasir Nawab
4. Fibres: History, Production, Properties, Market by Dieter Veit
5. Textile handbook by Hong Kong Cotton Spinners Association

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