FABRIC MAKING USING A SYNTHETIC FIBRE (PET FIBER)

A PRESENTATION ON TEXTILE INDUSTRY

BY

GROUP 7 MEMBERS

DEPARTMENT OF CHEMICAL ENGINEERING

FACULTY OF ENGINEERING
UNIVERSITY OF BENIN
BENIN CITY.

CHE 581
COURSE LECTURER: DR (MRS) E.T. AKHIHIERO

DECEMBER 1, 2016
 GROUP MEMBERS
S/ NAME MATRICULATION NUMBER
N
1. OCHUI PAUL ENG1202732
2. OGUNTIMEHIN DAMILOLA ENG1202734
3. OJAGUN NEDIN ENG1202735
4. OKOBI ESTHER DUMEBI ENG1202739
5. OKONOBOH SEAMUS ENG1202740
8. OKPIGHE WISDOM ENG1202742
6. OLADIP0 BOLAJI ENG1202743
7. OLONADE YUSUF ENG1202744
ABSTRACT
TABLE OF CONTENT
LIST OF TABLES AND FIGURES
 CHAPTER ONE
1.0 INTRODUCTION
Textile manufacturing can be said to be basically all about fibers, fabric (or similar

product) and colour. The word textile originally applied only to woven fabrics and

originated from the Latin word ‘texere’ meaning ‘to weave’. In recent times however,

the Textile Institute’s Terms and Definition Glossary defines textile as “a general term

applied to any manufacture from fibers, filaments, or yarns characterized by

flexibility, fineness and very high ratio of length to thickness”. The manufacture of

textile is and has always been a major industry in the world which is based on the

conversion of fiber into yarn/thread and the yarn into fabric. These are then dyed or

printed on depending on their purpose. The term fabric and cloth are used in textile

assembly trades as synonymous with textile. However, there are subtle differences in

terms of specialized usage. Fabric refers to any material made by weaving, knitting,

crocheting, or bonding that may be used for the production of further goods. Cloth

may be synonymous with fabric but is often used to refer to a finished piece of fabric

used for a specific purpose (e.g. table cloth). Textile, on the other hand, refers to any

material made of interlacing fibers.

Textile fibers are fibers that can be spurn into a yarn or fabric by various methods

including weaving, knitting, and braiding, felting, and twisting. The essential

requirements for fibers to be spurn into yarns include a length of at least 5

millimeters, flexibility, cohesiveness, and sufficient strength. Other important

properties include elasticity, fineness, and uniformity, durability, luster, thermal and

flammability characteristics.

1.1 CLASSIFICATION OF TEXTILE FIBERS

Textile fibers are classified according to figure 1.0 below;

Figure 1.0: Classification of textile fibers

1.2 NATURAL FIBERS

Natural fibers are made from animal, plant, and geological processes and are

biodegradable over time. They are classified according to their origin into the

following;

1.2.1 ANIMAL FIBERS

 The fibers which are obtained from animals are called animal fibers. Wool and silk

are common examples of animal fibers. It is important to note that animal fibers are

also called protein fibers because they are made up of protein molecules. Animal

fibers have high resiliency but weak when wet because they are bad conductors of

heat. Examples of some animal fiber, source and their attributes are shown in table

1.0 below;

Table 1.0: Animal fibers, source and attributes

Fiber Source Attributes

Byssus Pinna nobilis  Warmth

 Lightweight
Chiengora Dog  Fluffy

 Lightweight
Qivuit Muskoxen  Softness

 Warmth
Yak Yak  Heavy

 Warmth
Rabbit Rabbits  Softness
Wool Sheep  Warmth
Lambs wool Lamb  Softness

 Elasticity

 Warmth
Cashmere wool Indian cashmere goat  Softness
Mohair wool North African angora goat  Dyes well

lightweight
Angora wool Angora Rabbit  Softness

 Blends well with

 other fibers
Silk Silkworm  Smooth fabric finish

with high luster

Aralac Milk  Soft

 Silky

 Hygroscopic

1.2.2 PLANT FIBERS (CELLULOSIC FIBERS)

The fibers that are derived from plants are called vegetable fibers. The basic

material of all plant life is cellulose. Cellulose is made up of elements like carbon,

hydrogen and oxygen. These cellulose fibers have certain common properties like

low resilience, high density, and good conductor of heat. They are highly absorbent

and are resistant to high temperature Examples of some plant fibers, source and

attributes are shown in table 1.1 below;

Table 1.1: Plant (cellulosic) Fibers

Fiber Source Attributes

Abaca Abaca plant  Thin

 Lightweight
Coir Coconut  Strength

 Durability
Cotton Shrub  Lightweight

 Absorbent
Flax Herbaceous plant  Lightweight

 Absorbent
  Used to make linen
Jute Vegetable plant in the  Strength

linden family  Durability

Kapok Pentandra tree  Fluffy
Kenaf Hibiscus cannabis  Rough
Raffia Raffia palm  Carpet/rough
Bamboo Grass pulp  Lightweight

 Pliable fiber

 Absorbent
Hemp Cannabis  Strength

 Durability
Pina Pineapple leaf  Soft

 Lightweight
1.2.3 MINERAL FIBERS

They are the inorganic materials shaped in to fibers and are mainly used in the fire

proof fabrics. Asbestos is the example of mineral fiber. Mineral fibers are fire proof,

resistant to acids and are used for industrial purposes. Examples are given below

Table 1.2: Mineral Fiber

Fiber Source Attributes

Asbestos cloth Asbestos  Fire-resistance
 Lightweight
 Carcinogenic

1.3 MAN-MADE FIBERS

Also known as manufactured fiber, synthetic fibers generally come from synthetic

materials such as petrochemical products. Some synthetic fibers, however, are

manufactured from natural cellulose and are often referred to as modified or

transformed natural fibers. The third class of man-made fibers are the inorganics

such as fiberglass.

1.3.1 POLYMER SYNTHESIZED FIBERS

This class of fiber are illustrated in table 1.3 below;

Table 1.3: Polymer synthesized fibers

Fiber Structure Source Attribute

Nylon Petroleum  Durable

(Nylon 6-6) products  Strong

 Lightweight

 Dries

quickly
Polyester Petroleum  Durable

(Polyethylene products  Strong

Terephthalate)  Lightweight

 Dries

quickly
Polyolefin Petroleum  Elastic

product  Strong

 Lightweight

Spandex Petroleum  Elastic

products  Strong

 Lightweight
Acrylic Petroleum  Lightweight

products  Warm

 Dries

quickly
Modacrylic Petroleum  Lightweight

products  Warm

 Dries

quickly
Kevlar Aramids  Very strong

Nomex Aramids  Chemical

resistant

 Electrical

resistant

 Flame

resistant

1.3.2 REGENERATED/MODIFIED/TRANSFORMED NATURAL FIBERS

This class of fibers are illustrated in table 1.4 below;

 Table 1.4: Modified or transformed natural (cellulosic) fibers

Fiber Structure Source Attributes

Acetate Wood pulp  Lustrous

 thermoplastic

Rayon Wood pulp  Soft

 Lightweight

 Absorbent

1.3.3 INORGANIC FIBERS

This class of fiber is illustrated in table 1.5 below;

Table 1.5: Inorganic Fibers

Fiber Source Attributes

Glass, Fiberglass Mixed silicates  fire resistance

For the purpose of this report, we will focus on the properties and production

processes of one natural fiber (cotton) and one man-made fiber (polyester) into

fabrics.

CHAPTER TWO
2.0 COTTON AS A NATURAL FIBER

Cotton is the most important of the natural cellulosic fibers. It still accounts for about

50% of the total fiber production of the world, although man-made fibers have made

significant inroads into cotton's share during the last three decades. The structure of

cotton is shown in figure 2.0 below;

Figure 2: Structure

of Cellulose

Cotton is very nearly pure cellulose. Modern fiber theory suggests that each cellulose

molecule present within two or more crystalline regions of cellulose will be held

together. Between the crystalline regions in cotton, amorphous unordered regions

are found. Voids, spaces, and irregularities in structure will occur in these amorphous

areas, whereas the cellulose chains in crystalline regions will be tightly packed.

Penetration of dyestuffs and chemicals occurs more readily in these amorphous

regions. Cotton is a relatively stiff fiber and it is hydrophilic (water-attracting) in

nature.

Cotton is not soluble in common organic solvents but is soluble only in solvents

capable of breaking down the associative forces within the crystalline areas of
cotton. Most insects do not attack cotton; however, a major problem with cotton

results from fungi and bacteria being able to grow on cotton. Mildews feed on hot

moist cotton fibers, causing rotting and weakening of the fibers. Characteristic odor

and pigment staining of the cotton occurs when mildews attack. Cotton is only slowly

attacked by sunlight but over long periods sunlight degrades cotton, causing it to lose

strength and to turn yellow.

2.1 YARN PRODUCTION FROM COTTON

The step by step processing of cotton into yarn is shown in figure 2.0 below;

Figure 2.0: Step by step processing of cotton into yarn

2.1.1 CULTIVATING AND HARVESTING:

Cotton fibers grow in the seed hair pod (boll) of cotton plants grown and cultivated in

warm climates. The cotton bolls are harvested by stripper harvesters and spindle

pickers that remove the entire boll from the plant. The cotton boll is the seed pod of
the cotton plant, attached to each of the thousands of seeds are fibers about 2.5 cm

long. Figure 2.1 and 2.2 below shows a cotton plant and a stripper harvester
Figure 2.1: Cotton fibre Figure 2.2: Stripper harvester.

2.1.2 GINNING AND BALE-MAKING

The seed cotton goes in to a cotton gin. The cotton gin separates seeds and removes

the "trash" (dirt, stems and leaves) from the fiber. In a saw gin, circular saws grab the

fiber and pull it through a grating that is too narrow for the seeds to pass. A roller gin

is used with longer staple cotton. Here a leather roller captures the cotton. A knife

blade, set close to the roller, detaches the seeds by drawing them through teeth in

circular saws and revolving brushes which clean them away. The ginned cotton fiber,

known as lint, is then compressed into bales which are about 1.5 m tall and weigh

almost 220 kg. Only 33% of the crop is usable lint. Commercial cotton is priced by

quality, and that broadly relates to the average length of the staple, and the variety

of the plant. A roller gin and bales are shown in figure 2.3 and 2.4 below;

Figure 2.3: Roller gin Figure 2.4: Bales of clean cotton

2.1.3 BY-PRODUCTS:
The cotton seed can be pressed into a cooking oil or used for renewable energy

generation. The husks and meal are processed into animal feed, and the stems into

paper.

2.1.4 OPENING AND CLEANING:

Cotton mills get the cotton shipped to them in large quantities of about 500 pound

bales. When the cotton comes out of a bale, it is all packed together and still contains

vegetable matter. The bale is broken open using a machine with large spikes. It is

called an Opener. In order to fluff up the cotton and remove the vegetable matter,

the cotton is sent through a picker, or similar machines. The cotton is fed into a

machine known as a picker, and gets beaten with a beater bar in order to loosen it

up. It is fed through various rollers, which serve to remove the vegetable matter. The

cotton, aided by fans, then collects on a screen and gets fed through more rollers till

it emerges as a continuous soft fleecy sheet, known as a lap.

2.1.5 CARDING:

The cotton comes off of the picking machine in laps, and is then taken to carding

machines. The carders line up the fibers nicely to make them easier to spin. The

carding machine consists mainly of one big roller with smaller ones surrounding it. All

of the rollers are covered in small teeth, and as the cotton progresses further on the

teeth get finer (i.e. closer together). The

cotton leaves the carding machine in the

form of a sliver; a large rope of fibers. These slivers are coiled out of the coiling

machine. A carding machine is shown in figure 2.5 below;

Figure 2.5: Carding machine

2.1.6 COMBING AND DRAWING

Combing is optional, but is used to remove the shorter fibers, creating a stronger

yarn and drawing straightens the fibers. Several slivers are combined. Each sliver will

have thin and thick spots, and by combining several slivers together a more

consistent size can be reached. Since combining several slivers produces a very thick

rope of cotton fibers, directly after being combined the slivers are separated into

roving. Roving frames reduces the sliver to a finer thread, gives more twist, makes

more regular and even in thickness, and winds onto a smaller tube.

2.1.7 SPINNING

Most spinning today is done using Break or Open-end spinning, this is a technique

where the staples are blown by air into a rotating drum, where they attach

themselves to the tail of formed yarn that is continually being drawn out of the

chamber. The end product of this process is the yarn which is then transported for

fabric making.
 CHAPTER THREE

3.1 POLYESTERS

Polyester is a synthetic fiber which derived its name from two key words poly,

meaning many, and ester, a basic organic chemical compound. It is a long chain

polymers that links several esters within the fibers. The fiber content of polyester is
composed of at least 85% by weight of polymeric ester. The major polyester in

commercial use is polyethylene terephthalate (PET), others are Poly-4-

cyclohexylenedimethylene terephthalate and polyester ether. The polyester fibers all

have similar properties to include;

 Polyester fibers are extremely strong.

 Polyester is very durable: resistant to most chemicals, stretching and

shrinking, wrinkle resistant, mildew and abrasion resistant.

 Polyester is hydrophobic in nature and quick drying. It can be used for

insulation by manufacturing hollow fibers.

 Polyester retains its shape and hence is good for making outdoor clothing for

harsh climates.

 It is easily washed and dried. C6H4(CO2CH3)2

These desirable characteristics of Polyesters makes them very suitable in fabric

production. This study will focus on the use of (PET) polyester to produce yarn

2.4 PRODUCTION PROCESS

2.5 STEP 1: PRODUCTION OF PET POLYESTER

The production process begins with the production of PET Polyester .There are

two (2) ways to achieve this viz;

  Producing virgin polyester

 Producing polyester from recycled PET containers

2.6 PRODUCING VIRGIN POLYESTER

Virgin Polyester simply means a fiber that is made from reacting chemicals and not

from re-used PET containers. It is produced by heating Terephthalic acid with

Ethylene glycol. The chemicals are measured into a vat (or in a continuous process,

the chemicals may be automatically pumped in). A heating element under the vat

raises the temperature of the solution between 302-410" F (150-210° C). This first

reaction creates dihydroxydiethyl terephthalate.

This is then pumped into an autoclave, which is a sealed vat much like a pressure

cooker. The chemical in the autoclave is heated under pressure to about 536° F (280°

C). At this temperature the chemical transforms into PET. As it cools, it forms a

viscous liquid. This liquid is then extruded through a showerhead-like nozzle, dried,

and broken into chips.

2.6.1 MELT SPINNING

The chips of PET are next heated in another vat to 500-518° F (260-270° C). The hot

liquid is extruded through very fine holes in a metal disk called a spinneret. As the

liquid sprays out of the spinneret, it hardens into fiber form. The fibers are wound

onto a heated spool. At this point, the fibers form something like a thick rope, which

is called tow.
2.7 PRODUCING POLYESTER FROM RECYCLED PET CONTAINERS
When polyester is made from recycled PET, the first step is collecting used PET

containers. Yarn makers buy bales of recycled bottles from vendors or from

municipal recycling projects.

The bales of bottles are emptied onto a moving belt. Workers first sort the bottles by

color, separating green ones from clear ones. Then workers visually inspect each

piece, and remove anything, such as non-PET caps or bases, or any foreign objects,

so that the final result is strictly PET bottles. The sorted plastic then moves into a

sterilizing bath. The clean containers are dried and crushed into tiny chips. The chips

are washed again, and the light-colored batch is bleached. Chips from green bottles

stay green, and become yarn that will be dyed a dark color.

When the chips are thoroughly dry, they are emptied into a vat and heated, then

forced through spinnerets as in the melt spinning process of virgin PET polyester

same as for virgin polyester.

The finishing steps-drawing, crimping, cutting, baling-are the same as in the process

for virgin polyester.

2.8 STEP 2: DRAWING AND CRIMPING

The tow from the spool is next pulled through the heated rollers of a drawing

machine to three or four times its original length. Drawing increases the strength of

the fiber, and helps set the crystalline structure of the PET molecules into smooth
strings. The tow then passes through a crimping machine, which compresses the tow

and gives it a crinkled, accordion-like texture. This also adds strength. The crimped

tow passes to a dryer, and then is cut into lengths of a few inches and baled. At this

point, the short, fluffy, hairy fiber looks very much like wool.

Spinning into yarn

After the polyester is baled, a sample from each bale is inspected. Fibers are

tested for uniformity of strength and thickness. If the bale passes inspection, then

the cut tow is sent to a carding machine, which aligns the fiber into thick, rope-like

strands. The strands flow out of the machine and are coiled into barrels or open

containers. The thick ropes are then fed into a spinning machine. The spinning

machine twists the

The chips are emptied into a vat and heated, then forced through spinnerets. The

strands flow out of the machine and are coiled into barrels or open containers. The

spinning machine twists the strand into a much finer diameter, and collects the

finished yarn onto huge spools.

The chips are emptied into a vat and heated, then forced through spinnerets. The

strands flow out of the machine and are coiled into barrels or open containers. The

spinning machine twists the strand into a much finer diameter, and collects the

finished yarn onto huge spools.

strand into a much finer diameter, and collects the finished yarn onto huge spools.
Dyeing

The textile manufacturer buys polyester from the yarn manufacturer on

these spools. The yarn is next immersed in heated dye vats in the part of the

factory called the dye house. In case of yarn made from green recycled PET

bottles, the dye must be a dark hue. Other yarns arrive bleached white, and

these can be dyed any color desired. After dyeing, workers feed the yarn

through a drying machine .

Dyes are chemical substances which are used to change the color of a

textile material permanently. Dyes are defined as reactive pigments which are

used in the dyeing process for color transformation of textile materials.

They are two types of dyes:

 disperse dye

 reactive dyes.

Reactive dyes : are solely used to dye cotton

Disperse dyes : are used to dye polyester materials. It is a physical process,

which yields a chemical change. It is also defined a colored organic compound

that absorbs light strongly in the Visible region and can firmly attach to the fibre

by virtue of physical bonding between the group of the dye and the group on

the fibre.

CHARACTERISTICS OF REACTIVE DYES.

 Fixation occurs in alkaline conditions

 Are cheap comparatively

 Are soluble in water.

REACTIVE DYES ASSISTANTS

Salt:

 Used to increase the affinity of dye to fibre.

 Used to decrease the hydrolysis rate of dyes

 Increases absorption

 Amount of salt used depends on the shade to be produced. (i.e the more the

salt, the more the shade and vice versa.)

Alkali:

 Are used as a dye fixing agent.

 Are used to maintain proper PH in dye baths and thus to create alkaline

condition.

 The type and strength of alkali used depends on the reactivity of dye.

 Strong alkali [i.e. Caustic soda (NaOH)] →for weaker reactivity.

 Medium alkali [i.e. Soda ash (Na2CO3)]→ for medium reactivity

 Weak alkali i.e. [i.e. Sodium hydrogen trioxocarbonate ( NaHCO3)]→ for high

reactivity.

Urea : Helps to get required shade of dye. For dark shade, more quantity of urea

is required, for lighter shades, less urea is used.

 Soaping : Extra color is removed from fibre surface, thus wash fastness is

improved. Soaping increase the brightness and stability of dye.

REACTIVITY OF DYES.

Based on the reactivity of dyes, they are classified into two main classes. These

are:

 M dyes (also called di-chlorotriazinyle derivatives)

 H dyes(also called mono-chlorotriazinyle derivatives)

M dyes are more reactive (with cellulose) than H dyes at room temperature in

the presence of mild alkalis.

DYEING PROCEDURE(S)

The processes involved in the manufacturing of any fibre are basically grouped

into three stages .They are the:

 The Pre-dyeing process.

 The Dyeing process.

 The Post- dyeing process.

The Pre-dyeing process : simply connotes all the process involved in the

preparation of the fibre itself for dyeing. It is broadly classified into five stages:

 The Half bleaching stage

 The Direct filling

  Hot wash and Hot drain

 Overflow

 Cold drain.

The Dyeing Process : As the name implies, it simply involves the processes

that describe the chemical processes that take place when the color of the

fibre is transformed organically. Physically, we:

 Add dye stuff to the fibre

 A bag of Salt

The Post- Dyeing Procedure : this is the final stage of fabric preparation in

the dye-house. Here, the fabric is already dyed and as such, is made to under-

go certain processes for the sake of its quality and consumer-feel satisfaction.

The processes involved are:

 Soaping

 Reduction

 Softening.

THE DYEING PRINCIPLE

The dyeing principle is based on fibre reactivity. It involves the reaction of a

functional group of a dye stuff with a site on fibre to form a covalent link between

dye molecules and fibre polymer.

It occurs in two stages; or phases :

  The Exhaustion phase.

 The Fixation phase.

In the Exhaustion phase, the dye is absorbed by the material in the neutral medium.

In the Fixation phase, the reaction between dye and fibre takes place.

Cellulose is regarded as alcohol in its reaction with reactive dyes.

Knitting

The dried yarn is next fed into a particular kind of mechanical knitter called a

circular knitting machine. The knitting machine binds the yarn into a continuous tube

of cloth. The tube may be approximately 58 in (1.47 m) wide and several hundred

yards long.

Napping and shearing

To achieve the particular fuzzy texture of fleece, the knitted material is next fed

through a napper. The napper runs mechanical bristles along the cloth, raising the

surface of the textile. Next, the cloth is sent to a shearing machine, which uses a

precision blade to cut the fibers raised by the action of the napper. This same

process is used to make velvet, corduroy, and other textured pile fabrics.

Finishing

The fabric may next be sprayed with a waterproof material, or with some other

chemical finisher that sets the texture of the material. The material is next cut into

lengths, according to the customer's needs. The lengths of cloth are wrapped around
boards or cardboard planks. These wound lengths are called bolts. At this point, the

bolts are ready to be sent to the garment manufacturer. The manufacturer will cut

the fabric according to a pattern, and sew the cloth into a garment.
TURAL OR WOVEN/KNIT GARMENT OR
SYNTHETIC FIBER YARN FABRIC CLOTHING