Building blocks of children's fabrics: Fibres, Yarn and Fabric

Introduction

To understand children's fabrics let's learn some basics. In this article, I will introduce you to the main raw material of all fabrics - fibres. We will cover various types of fibres, how they are combined to make yarn and how yarn is assembled by various techniques to create fabrics. We will also delve into the fascinating history of fibres. 

Textile fibres

Textile fibres

Fibre is defined as a small thread like structure. It's characterised by having a length at least 100 times greater than its diameter. 

Flexibility, fineness and high ratio of length to thickness enable fibres to function as the raw material of textiles/fabrics. 

Textile fibres can divided into fibres of indefinite length called filaments and shorter fibres known as staple fibres.

Filaments are generally combined and twisted to form yarn, whilst staple fibres are spun to create yarn. Yarn is then typically woven or knitted into fabrics.

A piece of fabric contains hundreds of millions of fibres.

Fibre Types

Textile fibres are classified into two types:

• natural fibres
• man-made fibres

Diagram 1: Types of fibres

Natural fibres

Natural fibres occur in nature i.e. vegetable (cellulosic) or animal material. There is also natural mineral fibre, i.e. asbestos, though this is no longer used due to it's carcinogenic properties. Some include natural rubber in this group.

Vegetable fibres are derived from seed, bast (bark or outer layers of plant stem) or leaf. 

• Seed: cotton
• Bast/bark: flax, hemp and jute
• Leaf: sisal

Animal fibres are usually protein based. They can be divided into the following categories:

• Wool: sheep
• Hair: goats (mohair and cashmere), rabbits (angora)
• Silk: silkworms

Man-made (manufactured) fibres

These are divided into 3 groups regenerated, synthetic polymers and inorganic fibres.

Regenerated fibres are derived from natural polymers. There substances are not useable in their original form but can be reformed or processed to create useful fibres. One of the first regenerative fibres regenerated from wood pulp was rayon, also referred to as artificial silk or viscose. Modal and acetate are other examples of regenerated fibres. 

Synthetic polymers are made by polymerising smaller molecules into larger ones using industrial processes. Synthetic polymer fibres can be classified in a number of ways; for simplicity we will use the following classification based on their chemical and physical properties:

• Polyesters: any long-chain synthetic polymer composed of at least 85% by weight of an ester of a substituted aromatic carboxylic acid forming high-modulus high-tenacity (HM-HT) fibres.
• Polyamides: polymers having in the chain recurring amide groups, at least 85% of which are attached to aliphatic or cyclo-aliphatic groups (e.g. nylon, PVA, PVC).
• Aramids: polyamides, where each amide group is formed by the reaction of an amino group of one molecule with a carboxyl group of another (e.g. Kevlar, Nomex).
• Olefins: long-chain synthetic polymer composed of at least 85% by weight of ethylene, propylene or other olefin units (e.g. polypropylene, polyethylene).
• Elastomers: materials that, at room temperature, can be stretched repeatedly to at least twice their original length, and upon immediate release will return to approximately the original length (e.g. polyurethane, Lycra, Spandex).
• Acrylics: long-chain synthetic polymer composed of at least 85% by weight of acrylonitrile units

Inorganic fibre examples are carbon, glass, ceramic and metallic fibres.

Filaments, staple fibres and tow

Fibres can also be classified by physical form

• Filaments
• Staple fibres
• Tow

As mentioned previously, a staple fibre is of relatively short length. Most natural fibres are staple fibres. Their length range from a few millimetres to around a metre; typically between 3 and 20 cm in length.

• Short staple: 2-3 cm (e.g. cotton fibres)
• Long staple: >5 cm (e.g. wool fibres)

Filaments are fibres of indefinite length. Silks are the only natural filament fibres. Most regenerated and synthetic fibres are produced as filaments, which can be used in single or multifilament form.

Some filaments are also assembled to produce a ‘tow’ which is then cut or broken into required short lengths to produce staple fibres suitable for blending with other fibres..

A tow can mean two different things:

• synthetic fibre industry: a tow is a large assembly of filaments that is destined to be cut into shorter (staple) fibres.
• natural fibre industry: tow is the shorter fibre produced when the stalks are processed to extract the fibres (flax)

 Blending fibres

Blending fibres

Individual types of fibres can be used on their own or combined with other types of fibres to change the quality and in some cases the price of the end-product according to our need - this process of combining fibres is called blending. Example poly-cotton is a blend of cotton and polyester which has different characteristics i.e. easier to iron and cheaper than 100% cotton. 

Reasons for blending fibres: 

• compensate for weaker attributes/properties of one type of fibre
• enhance the performance of the resulting yarn or fabric
• provide a different appearance
• facilitate efficiency of processing i.e. spinning, weaving and knitting
• reduce costs

History of fibres

Historically, textile production was a domestic industry predominantly carried out by women. The fibres used were agriculturally derived e.g. wool, cotton, silk, hemp and flax therefore natural fibres. 

After the industrial revolution in the 1700-1800's, processes became mechanised, this filtered down to the manufacturing process of textiles as well. This made textile manufacture much faster and more efficient.

Child labour: making textiles during the industrial revolution https://www.history.com/topics/industrial-revolution/child-labor

The first man-made fibres, namely cellulose fibres derived from wood pulp and cotton rags, were developed in 1891.

Artificial silk was first produced commercially in the United States in 1910. This new material was called rayon and only cost half as much as natural silk. Rayon was used for clothing, home furnishing and industrial material.  

The first synthetic fibre - nylon, was created in 1935, from petrochemicals by an American chemical company called DuPont. This was initially used for hosiery and during World War II it was used exclusively for parachutes and airplane tires

The first polyester fibre- Terylene was manufactured in 1941 by a group of British scientists. However the initial work was borrowed from DuPont who later purchased legal rights to this fibre and sold it under heir own brand name Dacron. DuPont also invented an acrylic fibre called Orlon around the same time. This is a versatile fibre that can mimic wool and cashmere

Another American company called Owens Corning produces fiberglass fibres in 1942.

Olefin a synthetic polypropylene fibre is developed by an Italian chemist Giulio Natta in 1949. This has wide spread applications especially in carpet making.

Commercial production of modacrylic fibre began in 1949 by American company - Union Carbide Corporation. Modacrylic fibre were of the same composition and had similar properties to acrylic fibre however they were flame retardant. They are used in manufacture of personal protective equipment, faux fur and wigs. 

The golden age of acrylic and modacrylic fibre began in 1950s. Variations of acrylic and modacrylic fibres flooded the market under the names of:

• acrylics:  Acrilan, Zefran, Creslan, and Courtelle
• modacrylics: Dynel, Teklan, and Verel.

In 1958 another polyester fibre named Kodel was developed by Eastman Chemical Products Inc. also known as Kodak.

DuPont kept creating textile fibre milestones; in 1959 by inventing spandex, which can stretch at least 500 percent without breaking; later in 1965 by producing Kelvar: strong, lightweight, and flame- and abrasion-resistant fibre material.

In 1968, consumption of man-made fibres surpassed natural fibres with polyester leading the field. 

In the 21st century, the current thrust in research is to create functional fibres that are more sustainable, reusable and recyclable.  

Yarn

Making yarn

There are two definitions of importance for yarn:

Most staple fibres are made into yarn through a process that allows assembly of fibres to hold together in a continuous strand by drawing, spinning and twisting.

Basic yarn types are:

• Monofilament: single filament
• Multifilament: twisting of many filaments
• Staple or spun: staple fibres combined by spinning into a long, continuous strand

Typical yarn formations include: 

• Single (fibres combined into a single yarn)
• Ply/plied (two or more yarns twisted together)
• Cabled/corded (several plied yarns twisted together)
• Blended/compound (different fibre types combined in a yarn)
• Core spun (a yarn with one type of fibre, usually a filament, in the centre (core) of the yarn, which is usually covered (wrapped) by staple fibres)
• Fancy or effect yarns (yarns with special effects or deliberate irregularities, e.g. slubs (thicker portions) or loops occurring regularly or randomly along the length of the yarn)

Combining different fibres and yarn structures can be used to engineer a particular set of properties e.g. sewing thread is an example of yarn that is specifically engineered for a specific purpose.

Fabric

Processed yarn can be assembled in many different ways to produce a fabric.

A fabric is defined as ‘a manufactured assembly of fibres and/or yarns that has substantial surface area in relation to its thickness, and sufficient cohesion to give the assembly useful mechanical strength’

There are many ways of combining yarn to create a fabric. Some of the most important are:

• Weaving
• Knitting
• Nonwoven fabric production

The different ways of constructing fabrics result in wide variations in texture, appearance, drape (the way a fabric hangs) and hand/handle (the feel of a fabric); as well as performance characteristics such as strength, durability , comfort and protection.

The use of finishing techniques for fabric allows further refinement of these properties

Both fashion and textile designers will exploit the inherent properties and performance characteristics of different types of fabrics when designing and making children's clothing and other textile accessories.

Summary

In conclusion, the basic building block of children's garment fabrics or any other fabric for that matter are textile fibres. There are variety of fibres initially derived from natural sources but now mainly man-made or manufactured. Improvement of research and technology has enabled man to create fibres with a variety of attributes and functions to suit their utility. 

Fibres are combined by various processes into yarn.

Yarn is assembled using a variety of techniques to generate fabrics which can be further refined by finishing techniques.

Therefore with all the above combinations and techniques we are able to make an infinite numbers of fabric for a variety of uses. 

I hope you enjoyed this article please get in touch if further information is required.       

References

1. Textiles and Fashion: Materials Design and Technology Woodhead Publishing Edited by Rose Sinclair 2015
2. http://www.sbcounty.gov/museum/media/press-kit/fabrics-of-our-past/Fabrics-textile-timeline.pdf
3. https://www.plasticsmakeitpossible.com/whats-new-cool/fashion/types-of-fabric/polyester
4. https://textilevaluechain.in