Southeast University

Welcome to my

presentation on

‘TEXTILE FIBRE’

Md. Hadiul Islam

ContentsFundamentals of Textile & Classification of

Textile FiberFlow chart of synthetic process of MMF & Classification of MMFFiber FormsDenier, Filament denier, Cotton count , Tex & ConversionMan made fiber technology & Regenerated & Synthetic fiberBasic characteristics of MMFInfluence of chemical structure on propertiesFundamental of MMF ProductionGeneral principle of Spinning process & Spinning of polymerComparative Feature of Melt, Dry, Wet SpinningManufacture of Viscose Rayon & Factors affecting the quality of Viscose & Manufacturing process flow chart Flow chart of lyocell process & Schematic diagram of Lyocell & Cuprammonium Rayon

Fundamentals of Textile

Introduction A textile is flexible material consisting of network of natural or artificial fiber often referred to as thread or yarn.

fibers is defined as unit of matter characterized by flexibility, fineness, and a high ratio of length to thickness.

Fabric refers to any material made through weaving, knitting, crocheting, or bonding .

Apparel is anything that one puts on ones body. Clothing, shoes, hats, globes, & scarves are example of apparel items

1. Naturally occurring fibers of vegetable

origin.

2. Naturally occurring fibers of animal

origin.

3. Regenerated man-made fibers which

use some naturally occurring substance

as the raw material.

4. Synthetic man-made fibers which use

synthetic organic compounds as raw

material.

5. Mineral fibers which are entirely

inorganic.

Classification of Textile fibers

Synthetic fiber has beginning with chemistry;

A media is developed and filtered under pressure;

It is then extruded into continuous filaments;

The filaments are allowed to solidify ;

They are then stretched;

A finishing solution is then applied;

The bundle of filament is then crimped;

The final step before packaging and shipping is:

Cutting the fiber bundle into staple length

Flow chart of synthetic process of MMF

 

Man made fiber can be classified

into three classes:

1). Those made from natural polymers

2). Those made from synthetic polymers

3).Those made from inorganic materials

Classification of man-made fiber

Man made fiber

Organic

Inorganic

By transformation

natural polymer

From synthetic polymer

ViscoseCuproLyocellAcetate

TriacetateModal

AlginateElastodiene

PolyesterPolyamide

PolypropylenePolyvinyl

PolyethyleneElastane

ModacrylicAramidAcrylic

Carbon Ceramic

GlassMetal

Man-made fibers are produced in the forms of

Continuous Filament yarn Spun or staple yarn Tow

Mono filament

Fiber forms

The coarseness of yarn or filament is usually gauged as denier. Denier is a unit of measure for the linear mass density of fibers.

The denier of a yarn is the weight in grams of length of 9000 meters of that yarn.

i.e- If 9000 meters of yarn weigh 100 grams-the yarn is said to be 100 denier.The term micro denier is used to describe filaments that weigh less than one gram per 9000 meter length

Denie

r

Filament denier only relates to a single filament (D.P.F is commonly known as denier per filament) Total denier relates to a yarn, an agglomeration of filaments. D.P.F= Total denier/Quantity of uniform filaments

If a yarn of 100 denier is composed of either 20 or 60 filaments, then the filament denier will be: For 20 filaments yarn,D.P.F = 100/20 = 5 denier- coarse filament For 60 filaments yarn,D.P.F = 100/60 = 1.7denier-fine filament

Filament denier

Cotton countThe yarn numbering system based on length & weight originally used for the cotton yarns & now employed for most staple yarns spun on the cotton or short staple system.

The number of 840-yards in 1 lb is known as cotton count.Under this system, the higher the number, the finer is the yarn.

Tex is the unit measure for the linear mass density of fibers & is defined as the mass in grams per 1000 meters. Tex is more likely to be used in Canada & Europe. While denier remains more common in united states.The unit code is “tex”. The most commonly used unit is actually the decitex, abbreviated dtex, which is the mass in grams per 10,00 meters.

Tex

Conversions For 1s cotton count 840 yards of cotton weights = 1lb 840m weights = 453.6 × 1.093613298 gm˶ ˶

9000m weights = (453.6 × 1.093613298 × 9000)/840˶ ˶

= 5315 gm (equivalent denier or conversion factor)

50s cotton count = 106.3 denier

2/50s cotton count = 212.6 denier

106.3 denier = 50s cotton count

Again 9000 m of filament weigh 9 grams means, 9 denier

Then mathematically, 1000m filament will weight 1 gram, which is also 9 denierAgain we know, if 1000m filaments weight 1 gram, it is said to be 1 Tex So from the ‘linear mass density of fibers’ point of view 9 denier = 1.0000 tex 1 denier = 0.1111 texFrom above T= D × 0.1111

Or T = (5315/C) 0.1111 Or T = 590.5/C Or T× C = 590.5 C = 5315/D or D = 5315/C C× D = 5315

HOH

H

H

OH

OH

H

OH

CH2OH

H

B. Glucose

HO

H

H

OH

OH

H

CH2OH

H

Repeating unit B. Glucose

H

HH

OH

OH

H

OH

CH2OH

OH

H

CH2OH

H

H

O

O

OH

OH

HO

n

CELLULOSE

Molecular structures of some fiber forming polymer

WHAT ARE MAN MADE FIBER?A class name for various fibers (filaments) synthetically produced from fiber- forming substances.The first group, of which rayon and acetate are examples, are produced by regenerating and modifying natural fiber- forming material such as cellulose.The second group, frequently called synthetics and including such fibers as nylon and polyester, are produced from synthetic chemicals.The third group, produce from inorganic materials, is known as carbon, glass and ceramic fibers.

Man made Fiber Technology:

The man-made fibers, derived from naturally occurring polymers are known as regenerated fibers. For instance rayon and acetate are made of the same cellulose polymers that make up cotton. Example of regenerated fibers is Viscose, Cupro, Acetate, Lyocell, Alginate, Modal etc.

Synthetic FibersSynthetic fibers is the another group of man-made fibers. Synthetic fibers are made of polymers that do not occur naturally. They are produced entirely in the chemical plant or laboratory, almost always from by product of petroleum. Example of synthetic fibers is Polyester, Polyamide, Polyvinyl , Acrylic, Polyethylene etc.

A high softening point Solubility or melting ability for spinning Adequate tensile strength A high modulus or stiffness

Regenerated Fiber

Basic Characteristics of man-made Fiber

Figure: Cellulose based polymers

When X represent hydrogen, the polymer is Glucose.The rayon fiber can be formed by converting the –OH groups to xanthate groups(e.g.-OC(S) SNa .

Cell-Xanthate

H

H

n

CH2OX

H

H

OXOX

OX

H

S

SNaCell-O-C

Influence of chemical structure on properties

Substitution of –OH groups by acetyl groups (-OC(O)CH3), than the polymer is called acetate. Cell-OX + 2(Acetate groups) =Cell-AcetateCell-OX + 3(Acetate groups) = Cell-Tri-acetate

Olefins(alkenes), a family of hydrocarbon compounds which are produced from the refining of petroleum and natural gas contains one double bond between two carbon atoms. The chemical formula can be represented as CH2=CHR, with R representing any of several possible atoms or groups of atoms in the repeating unit of a polymer. The compound has the following chemical structure as shown in the figure.

CHCH2

R

n

Polyolefins

When R represented as –CH3 group, then the polymer is called Polypropylene. It has moderately high melting point (176°C) that can be melt spun into fiber useful for several types of clothing, upholstery, carpets and non woven fabrics.

When R is hydrogen the polymer is polyethylene. A relatively low melting material(137°C) that finds uses as a fiber in industrial application –e.g. non-woven fabrics- but not in most household application.

When R represents a cyano , or nitrite, group (-C= N), containing carbon and nitrogen linked by a triple bond. In this case the polymer obtained is polyacrylonitrial, an acrylic That does not melt without decomposition and therefore must be solution spun into fibers used in clothing, drapes, and carpets.

It is observed from the structure variation that the methyl and cyano groups in polypropylene and polyacrylonitrile raise melting points. 

Most synthetic and cellulosic manufactured fibers are created by “extrusion” forcing a thick, various liquid through the tiny holes of a device called a spinning to form continuous filaments of semi-solid polymer.In their initial state, the fiber-forming polymers are solids and therefore must be first converted into a fluid state for extrusion. This is usually achieved by melting, if the polymers are thermoplastic synthetics (i.e. ,they soften and melt when heated), or by dissolved them in a suitable solvent if they are non-thermoplastic cellulosic. If they cannot be dissolve or melted directly, they must be chemically treated to form soluble or thermoplastic derivatives.

Polymer processing of MMFFundamentals of Man- made Fiber Production

The manufacturing of fibers from natural or synthetic polymer involves the following technical operations:

Preparation of spinning fluid from solid polymer or directly from monomers.

Spinning:• Extrusion of spinning fluid through spinnerets,• Emerging fluid jets into filaments of required thickness,• Solidification of polymer material, •And collection the obtained filaments on a suitable mechanical device ( rotating bobbin, centrifuge, wind up package etc.)

Mechanical, thermal and chemical treatment of the fibers to improve their properties.

General Principles of Spinning Process:

There are typically three types of spinning for polymers- Melt, Dry and Wet.Melt Spinning:In melt spinning the fiber forming material is melted and extruded through spinneret, and the jets harden into solid filaments as they cool on emerging from the spinneret, Nylon is a melt-spun fiber.

Spinning of Polymers

Dry Spinning:In dry spinning the fiber forming is dissolve in a solvent before the solution is extruded. As the jets of the solution emerge from the spinneret, a stream of hot air causes the solvent to evaporate from the spinning solution, leaving the solid filament. Acetate is a dry spun by extruding acetone solution of cellulose acetate into hot ho air.Wet spinning:

In wet spinning them solution of fiber forming material is extruded into coagulating bath that causes the jets to harden as a result of physical or chemical changes.V iscose, for example of wet spun.

Fig: Diagram of Melt, Dry, Wet Spinning

Features melt dry WetInvestment cost low High Low

Hazard Non-toxic Toxic(risk of expolsion)

Toxic

Heat of spinning High High Low

Spinneret hole 2 to many thousand

300-900 20,000-75,000

Spinning speed 2500-3000 ft/min

2500-3000 ft/min

150-300 ft/min

Comparative features of melt, dry and wet spinning

Wood contains other substance like lignin, beside cellulose. So it is purified, treated with caustic soda, which converts it into alkali cellulose, then treated with carbon disulphide, which converts it into sodium cellulose xanthate & then dissolved in dilute solution of caustic soda. The solution is then ripened & then spun into an acid coagulating bath, which precipitate the cellulose in the form of a viscose filament.

Manufacture of Viscose RayonChemistry of viscose rayon

Cell-OH + NaOH Cell-O

- Na+

Cell-O- Na+ + CS2 Cell-O-C

S

S- Na+

Cell-O-C H2SO4

S- Na+

S + Cell-OH

Cellulose, Soda cellulose, Sodium cellulose Xanthate, Regenerated Cellulose.

Manufacture process flow chart of viscose Preparation of the wood pulp Conditioning of wood pulp Steeping (Formation of soda cellulose) Shredding (Cutting) Ageing Churning (Xanthation or sulphidising) Mixing (Dissolving) Ripening Spinning Wind up/Cutting 

Schematic Diagram of lyocel process

Like Viscose, Cuprammonium Rayon is also a regenerated cellulose fiber. Cotton Linters are used as the source of cellulose for this rayon. Cuprammonium solution

Ammoniacal Copper Oxide solution, known as Cuprammonium Hydroxide solution[Cu(NH3)4(OH)2] is obtained by pouring a solution of Ammonia in water over Copper turnings, at 5 C. ͦA solution of Copper Sulphate (CuSO4.5H2O) is mixed with caustic soda to form Copper Hydroxide. CuSO4 + NaOH Cu(OH)2

Purified and bleached cotton linters are added and stirred.The copper cellulose thus formed may be stored for a long time. The liquor is filtered off. The deaearated cellulose solution is ready for spinning. Cuprammonium cellulose solution is discharged from the spinneret into a solution of sulfuric acid in the form of relatively thick threads which are subsequently stretched to very fine filaments by a rapid pull.

 

Cuprammonium Rayon

Viscose

Acetate

Cupro

PropertiesFiber

Tensile strength (GPD) Moisture

absorptionDensity

(1.5-2.4) at dry(0.2-1.2) at wet

Absorb moisture at 70°F & 65% Rh 13%

1.5 gm/cc.

(1.1-1.3) at dry(0.65-0.75) at wet

Moisture absorb 6.5% at 65% Rh

(1.7-2.3) at dry( 1.1-1.35) at wet

12.5% under standard condition

The filament are available in 1.3 denier

Continuous filament 1.5-5.5 denier

Properties Of Cellulosic Fibers

PropertiesFiber

Tensile strength (GPD) Moisture

absorptionDensity

Nylon 6

Nylon 6/6

Polyester

4.2-5.8 4% 1.14 gm/cc

4.3-8.8 (4-4.5)% 1.14 gm/cc

Properties of Synthetic polymer fiber