Textile fiber theory

Textile Fiber theory

Textile Fiber- Textile Fiber is a smallest part of the fabric. This single hair like strand of fabric is called a

fiber. They are the basic building block used in manufacturing fabric. It can be called a body that is very long in relation to the thickness.

Uses of Textile fibers & fabrics Apparels Home furnishings Household textiles Building Trades

CLASSIFICATION OF FIBERS

Classification based on Length of fibers:Fibers come as short fibers and long fibers and theirlength is an important property of fibers. Staple fiber- is a unit of matter which is usually at

least 100 times longer than it is thick. They are short length fibers. All natural fibers like cotton, flax, wool except silk are staple fibers.

Filament fiber- is a very long fiber. The length of filaments may range from a few 100mts e.g. Silk to several km, all Manmade fibers.

Classification based on source of fibers: Natural Fibers- are those which are obtained from

different sources of the nature. Three Sources:

Vegetable/ plant Animal

MineralPart of the Plant-

Seed- Cotton Bast / Stem- Jute, Linen Leaf- Sisal Fruit- Coir

Animal- Silk, Wool Mineral- Asbestos.II) Manufactured Fibers – Regenerated fibers- manufactured from any

of the natural source eg., cellulose, (waste cotton fibers or wood pulp) or protein treated with different types of chemicals.

E.g. - Rayon –regenerated cellulose fiber.

Synthetic fibers- are produced from chemicals by combining carbon, oxygen, hydrogen & other simple elements into larger complex molecular combinations called polymers. E.g. - Nylon, Polyester, acrylic

Metallic fibers- are produced by mining & refining metals such as aluminum, silver & gold.

IDENTIFICATION OF FIBERS- Visual Inspection- Can identify a fabric by its

appearance but accuracy in identifying comes through experience. The appearance properties of different fibers can help in identifying a fabric e.g., Silk is smooth, shiny and fine.

Cotton is also smooth but looks dull, wool is most definitely rough.

Burning Test- Burning test is a simple and reliable test. The burning test does not identify the fiber in particular but indicates its group. Cotton, flax and rayon will have similar results when burnt as they are all basically cellulosic in nature.

Cotton, Linen, Coir- Smell of burning paper

Silk, wool- smell of burning hair. 

Chemical Test- final verification of fibers is done by this test.

  Acetone 100% Hydrochloric acid 20% Sulfuric acid 60% Sulfuric acid 70% Chlorine bleach 5% Formic acid 90%

ACETATE Soluble Insoluble Soluble Soluble Insoluble Soluble

ACRYLIC Insoluble Insoluble InsolubleInsoluble

depending on typeInsoluble Insoluble

COTTON Insoluble Insoluble Slightly soluble Soluble Insoluble Insoluble

HAIR Insoluble Insoluble Insoluble Insoluble Soluble Insoluble

HEMP Insoluble Insoluble Slightly soluble Soluble Insoluble Insoluble

LINEN Insoluble Insoluble Slightly soluble Soluble Insoluble Insoluble

MODARYLICSoluble or Insolubledepending on type

Insoluble Insoluble Insoluble Insoluble Insoluble

NYLON Insoluble Soluble Soluble Soluble Insoluble Soluble

OLEFIN Insoluble Insoluble Insoluble Insoluble Insoluble Insoluble

POLYESTER Insoluble Insoluble Insoluble Insoluble Insoluble Insoluble

RAMIE Insoluble Insoluble Slightly soluble Soluble Insoluble Insoluble

RAYON Insoluble Insoluble Soluble Soluble Insoluble Insoluble

SILK Insoluble Partially Soluble Soluble Soluble Soluble Partially soluble

Wool Insoluble Insoluble Insoluble Insoluble Soluble Insoluble

PROPERTIES OF FIBERS-Primary PropertiesA fiber must possess these to qualify as a

suitablesubstance for use in forming textile fibers. Theseinclude:- Length to Width Ratio-

The fiber must be long enough to allow processing & slender enough to be flexible.

Strength (Tenacity)-Fiber must possess enough strength to withstand chemical or machine processing. It’s related to durability of fiber & final product.

Flexibility/Pliability-The ability of a fiber to resist repeated bending without rupture is flexibility or pliability.Important for end use :

Influence the hand/ feel. Draping/ falling quality of apparel & home

furnishing. Capacity to move with body& permit freedom

movement. Durability of end product. Cohesiveness or Spinning Quality- It is ability of fibers to adhere/ stick to each

other or cling together during yarn manufacturing process.

Uniformity-To convert fiber into yarn, a fiber must possess similar length & width, cohesiveness, strength & flexibility. It produces even yarns & fabrics of uniform appearance.

Secondary Properties- Physical Properties - Physical Shape-

This includes average length, surface contour, surface irregularities & cross section.

Fineness-Relative sizes, Diameter are measures of fineness of the fiber.

Luster-Luster is the gloss, sheen or shine that fiber possesses. Determined by the way light is reflected from the surface of the fiber.

Effect of Cross sectional shape- Smooth surface reflect light back to their sources &

appear shiny. Silk has more regular surface so gives distinct luster.

Colour-Fibers are available in wide range of colors. White or colourless fibers are preferred as they can be dyed or printed with different colours.E.g. Wool- off white, tan, brown, gray or black

Cotton- usually white or cream Manmade- exist in wide range .

Moisture Absorption-The amount of water a fiber can absorb from the atmosphere or water bath may affect apparel comfort, fabric care, and textile processing & fiber price.

Fibers are usually categorized: Hydrophilic- Those ‘like’ or absorb water. Hydrophobic- those that ‘dislike’ or do not absorb water.

Elongation & Recovery-Elongation- the amount of stretch or extension that a fiber will accept is referred as elongation. Elastic recovery- it is the ability of a fiber to recover its original length immediately after removal of the load. If fiber recovers completely from deformation, it exhibits 100% elastic recovery.

Resiliency-The ability of fiber to return to its original shape after compression, bending, creasing, twisting or similar deformation is resiliency.

Abrasion Resistance-The wearing away of a material by rubbing against another surface is known as Abrasion. Abrasion around collars, cuffs in apparels occurs as fabric move & rub against another surface, such as human body, arm of a chair.

Thermal Properties-The reaction of a fiber to heat & flame are considered its thermal properties. Most textile fibers burn when exposed to a flame.

Fiber with low incidence of burning will be safer than fibers that burn quickly.

Some fibers melt &drip- Nylon Self extinguisher – Wool, silk Glow afterwards- Cotton , Rayon

Biological Properties-

Its behavior of fibers towards insects, beetles, moths, microbes, bacteria, fungi, mildews etc.

Chemical Property- Reaction to Bleaches- Bleaches are chemical solutions designed to

remove discoloration. Hydrogen peroxide is used.

Reaction to Alkalies- Cellulosic- Not harm by alkalies. Protein- Harmful.

Reaction to Acids-Concentrated cold or dilute hot mineral acids such as sulphuric acid, will destroy it- Cellulosic Wool

Resistant to dilute acids. Although wool is damaged by hot sulphuric

acid, it is not affected by other acids, even when heated.

NATURAL CELLULOSIC FIBERS- The natural cellulosic fibers are those that occur in

fiber form as parts of plants. Sometimes these are also called Vegetable or Plant fiber.

They are obtained from 4 plant parts: -Seed hair, Fruit Husk, Plant stem & Plant leaf. Burn easily, give smell of burning paper.

Cotton- It is obtained from seed hair & most widely used.

Kind & Types: Variations occur because of growth condition such as: -

Soil, climate, fertilizers & pests. The quality depends on:-

colour ( degree of whiteness) length ( staple or filament) fineness strength

Manufacturing Process of Cotton- Cultivation of Cotton-Buds appear a few weeks after the plant

emerges. After 3

weeks Creamy white blossoms

Pink to reddish purple

3 days Petals fall off & get the ripened seed pod

Pod expand to form cotton ball

Pod expand to form cotton ball

50 -80 days

Ball opens

Fleecy cotton fibers appear

Harvesting-Harvesting is one of the final steps in the production of cotton crops, it is one of the most important. The crop must be harvested before weather can damage or completely ruin its quality and reduce yield.Types: Hand Mechanical

Ginning & Bailing-Raw cotton contains seeds, leaf fragments, dirt etc. Cotton seeds approx. weigh 2/3 of raw cotton. Seeds are removed by Cotton Gin.

Gin separates the fiber called cotton lint from its seeds. Cotton fiber is compressed into rectangular bales.

Properties of Cotton: Length to width ratio – 6000:1 (for longest &

best) to about 350 :1 for shortest & coarsest. Strength- Good  Colour- Vary from near white to light tan. Depends

on climatic condition, soil, and environment. Elasticity- It is relatively inelastic. Cotton fibers

exhibit 75% elastic recovery at 2% extension. Resiliency- Cotton textiles wrinkle & crease

readily. Drapability- It is ability of fiber to hang easily &

fall graceful shape& folds. Cotton drapes well. Absorbency- It is the ease with which moisture

can penetrate into fiber determines its absorbency. Cotton has Good Absorbency.

Thermal Property- It has relatively high degree of heat conductivity. It Burns readily & quickly with odour of burning paper. Long exposure above 150 C gradually decomposes fiber. Safe ironing temp.- 204 C for cotton.

Chemical Property- Reaction to Bleaches- Bleaches are chemical solutions

designed to remove discoloration. Hydrogen peroxide is used.

Reaction to Alkalies- Not harm by alkalies Reaction to Acids- Concentrated cold or dilute hot

mineral acids such as sulphuric acid will destroy it. Cleanliness & Wash ability- Cotton attracts dirt

particles as it is rough. Resistant to alkalies present in detergents so easy to wash.

Effect of Light- Cotton fibers oxidize, turning yellow & losing strength with prolonged exposure.

Biological Property- Not attacked by most insects. It is

susceptible to attack of fungi & mildew. Only heavily starched fabrics are likely to be attached by silverfish.

Characteristics of Cotton Fabric – It is soft and comfortable. It has good strength. It is easy to handle and sew. It drapes well. It is flame retardant. It is machine-washable and dry-cleanable. It is hydrophilic, which means that cotton have

excellent absorbing capabilities. Garments made of cotton absorb perspiration, thus keeping one more comfortable.

Cotton wrinkles easily. To resist this, cotton is being blended with many other natural or synthetic fibers.

Uses of Cotton Fabric- Cotton Apparel / Garments - Garments made of

cotton are very soft, comfortable and weather friendly. Normally all types of garments are made of cotton fabrics; formal, casual and even industrial clothing.

Cotton Home Furnishing – Cotton home furnishing is preferred because of the fabrics strength and durability characteristics. E.g. - rugs or durries, draperies and curtains, bedding products, etc.

Cotton Handbags and Luggage – Due to strength, cotton handbags and luggage are more widely preferred. The heavier cotton fabric is used in these kinds of products.

Cotton Canvas- Medium to heavyweight cotton fabric is used in range of canvas products like shoes, tents, etc. Apart from these, cotton fabrics are also used in medical and surgical products, bookbinding cloths.