Nylon and Polyester

Nylon and Polyester – The Fabrics Dominating Our Daily Life

The origin of nylon fabric and polyester fibres dates back to the 1930s and 1940s. Both nylon and polyester are durable and light-weight synthetic fibres with properties like stretch resistance, wrinkle resistance, easy-care, and shrink resistance. Since both replaced natural fibres as more sustainable alternatives with unique characteristics, it may be tough to decide which one is better - nylon or polyester.


So who discovered nylon? Wallace Carothers is credited with the discovery of nylon fabric in 1935. Even though it was not available for public use until after the Second World War, nylon was in extensive use among the military for tents and parachutes. Polyester, however, came into existence in the early 1940s and gained popularity in the 1950s.


As important synthetic fibres, nylon and polyester find a wide range of applications in today's life. So let's get our hands on some nylon and polyester fabric information – structures of nylon and polyester, nylon and polyester examples, and their uses. 


Nylon

Let us first talk about nylon fabric in detail. Nylon belongs to a group of synthetic polymers termed as aliphatic polyamides or thermoplastics that are petroleum derivatives. The discovery of nylon was driven by the necessity to replace weak natural fibres with something strong and durable like silk. Initially used for military purposes, the uses of nylon have diversified. Now it is the second most commonly used fabric after cotton.


Preparation of Nylon

 Nylons are condensation copolymers and are prepared by reacting equal parts of a dicarboxylic acid and a diamine. Nylon 6, 6, made up of monomer units hexamethylenediamine and adipic acid is the most common variant of this synthetic fibre. Each monomer is present alternately in the copolymer forming the repeating unit and each contributing six carbon atoms to the polymer chain. The final nylon structure is the result of the following reaction: 


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Properties of Nylon

Some of the significant features of nylon include:

  • Dense molecular structure

  • Extremely elastic

  • Resilient and durable

  • Abrasion-resistant

  • Water-resistant

  • Resistant to stains, UV rays, heat, and chemicals

  • Resistant to mould and mildew

  • Dries quickly


Uses of Nylon

Nylon has many applications. Some of them are:

  • Car components close to the engine

  • For making toys and plastic utilities

  • For making swimwears (due to its waterproof nature)

  • Nylon resins are used in food packaging

  • Ropes, tents, tires and other military supplies


Polyester

Now let's define polyester, discuss the source of polyester, and the polyester fabric uses. Like nylon, polyesters are a group of synthetic compounds that can be knitted or woven into a fabric. Polyester became a popular textile fabric in the 1950s and is now widely used for industrial and decorative purposes as well. Polyethylene Terephthalate (PET) and PCDT are the two most commonly used polyesters today.


Preparation of Polyester

So how is polyester made? The formation of polyester involves a chemical chain reaction. In the first step, purified terephthalic acid (PTA), monoethylene glycol, and dimethyl terephthalate react to form bis terephthalate. Finally, PET is formed on heating the bis terephthalate. Being exceptionally malleable, PET can be combined into thin, long, and unbroken fibres. There are two types of manufactured polyester – the filament yarn and the staple fibre. The following polymerization reaction obtains the final polyester structure:

 

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Properties of Polyester Fibre

Now let's talk about some characteristics of polyester fibres:

  • Strong, resilient, and durable

  • Resistant to shrinking and stretching

  • Resistant to several chemicals

  • Dries quickly

  • Wrinkle-resistant

  • Resistant to abrasions, moulds, and mildew

  • Can retain heat-set pleats

  • Can be recycled 


Uses of Polyester Fibre

Some applications of polyester include:

  • Polyesters are a popular choice to make several types of apparel. Examples of polyester clothing include shirts, pants, jackets, hats, and more.

  • Home furnishings such as bedsheets, bedspreads, curtains, pillows, carpets, and upholstered furniture are mostly made from polyester fibres.

  • Industrial uses include polyester films for food packaging, video and audiotapes, electrical insulators, liquid crystal displays, capacitors, conveyor belts, etc.

  • Polyester also comes in handy for making products like PET bottles, pianos, guitars, threads, hoses, sails, and high-strength ropes.

FAQ (Frequently Asked Questions)

1. How do Natural Fibres Differ from Synthetic Fibres?

The differences between natural and synthetic fibres are:

  1. Source: All types of natural fibres are procured from natural sources, but synthetic fibres are entirely human-made.

  2. Form: The length of natural fibres cannot be manipulated, and they come in filament or staple form. Synthetic fibres are found in filament form, can be converted to staple, and spun into the desired length.

  3. Spinning: Natural fibres do not require spinning for filament production. But spinning is needed for filament production in synthetic fibres.

  4. Yarn production: While yarn production of natural fibres does not require chemical solutions, synthetic yarns are produced by using solutions of chemicals.

  5. Purity: Natural fibres may harbour dust and impurities. Synthetic fibres are free from impurities.

  6. Durability: Natural fibres are not as durable as synthetic fibres.

  7. Dyeing: Natural fibres can be conveniently dyed, but synthetic ones do not take up colour easily.

2. What is the Difference Between Nylon and Polyester?

The following are the bases of differences between nylon and polyester:

  1. Chemical nature: While nylon is a polyamide, polyester is a polyethene naphthalate.

  2. Manufacture: Nylon is prepared as a liquid followed by mechanical spinning and drying into individual fibres. Polyester is made into threads from chemical solutions.

  3. Wearability: Nylon has low moisture absorbency, and polyesters are wrinkle-resistant.

  4. Durability: Nylon fabrics are unusually durable, abrasion-resistant, as well as resistant to many chemicals and oils.

  5. Flammability: While nylon first melts followed by rapid burning, polyesters melt and burn simultaneously.

  6. Environmental impact: Most nylons are made from the byproducts of oil refineries hence contributing to efficient waste management. While polyesters are non-biodegradable and recyclable but not really obtained out of commercial waste management programs.

  7. Appearance: Nylons have a lustrous appearance, and polyester fabric is slightly slick.

  8. Effect of sunlight: Nylon fades quickly on exposure to the sun. Polyesters bind dyes strongly and remain unaffected by the sun's radiations.