ASSIGNMENT On

Polyester Fiber Production Process

Course Title: Textile Raw Material-II

Course code: TE-226

Submitted to Submitted by

Dr Engr Md Saifur Rahman Md. Rakibul Islam Professor Student ID: 141-23-3783

Department of TE Section:A

Daffodil International University Department of TE

Daffodil International University

Date of Submission:

18-08-2015

Polyester Fiber Production Process

Introduction:

Polyester (aka Terylene) is a category of polymers which contain the ester functional group in

their main chain. Long chain polymers chemically composed of at least 85% by weight of an

ester and a dihydric alcohol and terephthalic acid”. The name “polyester” refers to the linkage of

several monomers (esters) within the fiber

Polyester

Raw material of polyester fiber:

Types of polyester:

1. PET Polyester:

2. PCDT polyester:

Production process of polyester:

There are two process used to polyester fiber production:

These are traditional method and latest modern method.

Traditional process:

Latest modern process:

Type of polyester fiber blending

Polyester and Cotton

1. Resist wrinkles

2. Resist stains

3. Retain shape

Polyester and Wool

1. Wrinkle resistance

2. Shape retention

3. Increase durability

Polyester and Rayon

1. More durable

2. Shape retention

3. More resilience

Manufacturing process of polyester

Polymerization

To form polyester, dimethyl terephthalate is first reacted with ethylene

glycol in the presence of a catalyst at a temperature of 302-410°F (150-

210°C).

The resulting chemical, a monomer (single, non-repeating molecule)

alcohol, is combined with terephthalic acid and raised to a temperature of

472°F (280°C). Newly-formed polyester, which is clear and molten, is

extruded through a slot to form long ribbons.

Drying

PET polyester fabrics are readily dried at 120˚C and are normally handled

on pin or clip sentres. Care must be taken to ensure that the fabric is not

stentered under heavy tension. If it is necessary to remove scouring creases,

the damp fabric should be stentered out, without overfeed, to a width which

exceeds the scoured width by 7-14 mm per m (¼-½ in. per yd.), and then

drier at 140-150˚C. Relaxed drying methods are preferred for caustic soda

softened fabrics and some yarn dyed fabrics.

Melt spinning:

Polymer chips are melted at 500-518°F (260-270°C) to form a syrup-like

solution. The solution is put in a metal container called a spinneret and

forced through its tiny holes, which are usually round, but may be

pentagonal or any other shape to produce special fibers. The number of holes

in the spinneret determines the size of the yarn, as the emerging fibers are

brought together to form a single strand.

At the spinning stage, other chemicals may be added to the solution to make

the resulting material flame retardant, antistatic, or easier to dye.

Drawing the fiber

When polyester emerges from the spinneret, it is soft and easily elongated up

to five times its original length. This increases the strength, tenacity, and

resilience of the fiber. This time, when the filaments dry, the fibers become

solid and strong instead of brittle.

Drawn fibers may vary greatly in diameter and length, Also, as the fibers are

drawn, they may be textured or twisted to create softer or duller fabrics.

Winding

After the polyester yarn is drawn, it is wound on large bobbins or flat-wound

packages, ready to be woven into material.

Physical properties of polyester:

Chemical properties of polyester:

Effect of acids:

These polymers are resistant to acids.

Effect of alkalis:

Alkaline conditions as seen in laundering hydrolyze the ester groups in polyester polymers. The

crystalline nature prohibits hydrolysis to a greater extent and it is the surface of filament which

gets hydrolyzed. Continued laundering results in hydrolysis and materials get fewer as the

surface film of the fiber gets lost.

Effect of bleaches:

It does not require bleaching. It retains its whiteness and requires only chlorine bleaches to be

used when essential.

Sunlight: It withstands the sun’s ultra-violate radiations and is resistant to acidic pollutants in

atmosphere.

Color Fastness: It is not easy for dye molecule to penetrate the fiber when dyed, it retains its

color after regular wash.

Micro-Organisms: It is resistant to bacteria and other micro-organisms.

Uses of polyester fiber:

Apparel: Every form of clothing

Home Furnishings: Carpets, curtains, draperies, sheets and pillow cases, wall coverings,

and upholstery

Other Uses: hoses, power belting, ropes and nets, thread, tire cord, auto upholstery, sails,

floppy disk liners, and fiberfill

Polyester was one of the enormous man-made fiber which was discovered around the period of 40’s and it

has been manufactured on an industrialized level since 1947. Polyester fibers are the first choice for

apparel.

Reference:

1. Online textile blog.

2. Wikipedia

3. "Sir Joseph Wilson Swan". Encylopaedia Britannica. Retrieved 27 April 2015.

4. Jump up^ How It Works: Science and Technology. Marshall Cavendish Corporation. 2003.

p. 851. ISBN 9780761473145.

5. Jump up^ Garrett, Alfred (1963). The Flash of Genius. Princeton, New Jersey: D. Van Nostrand

Company, Inc. pp. 48–49.

6. Jump up^ Editors, Time-Life (1991). Inventive Genius. New York: Time-Life Books. p. 52. ISBN 0-

8094-7699-1.

7. Jump up^ Day, Lance; Ian McNeil (1998). Biographical Dictionary of the History of Technology. Taylor

& Francis. p. 113. ISBN 0415193990.

8. Jump up^ Woodings, Calvin R. "A Brief History of Regenerated Cellulosic Fibres". WOODINGS