Polyester is the most commonly used synthetic fiber. It is manufactured through a condensation reaction between an organic alcohol and a carboxylic acid, forming an ester linkage. Polyester fibers have properties like resilience, wrinkle resistance, shape retention, durability and washability. However, they also have disadvantages like poor moisture absorption and generating static electricity. Polyester is dyed using disperse dyes at high temperatures via HTHP or carrier methods. It has many uses including in clothing fabrics due to its desirable qualities.

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Textile Fiber II (Tex-229)
7. Polyester fiber
Dept. of Textile Engineering
Southeast University

2. Introduction
● Polyester is the most used synthetic fiber.
● can be manufactured in different shapes and sizes
for specific purposes.
● most commonly are prepared from a condensation
reaction
● between an organic alcohol (containing hydroxyl
[OH] groups) and a carboxylic acid (containing
carboxyl [COOH] groups).
● These two functional groups react to form the
characteristic ester linkage, a chemical group with
the structure.
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6. Reaction mechanism
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7. Reaction involved
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9. Reaction involved
●
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12. Polyester Dyeing with Disperse Dyes
Polyester is undyeable below 70-80°C and the rate of diffusion of
disperse dyes into polyester below 100°C is so low.
● HTHP Method: 130°C temperature is required for its dyeing. For
dyeing using the HTHP method, special equipment is needed,
which can withstand such conditions.
● Carrier Method: The fiber can be dyed in a boiling dyebath at
atmospheric pressure in the presence of the carrier. The main
function of the carrier is to reduce the Tg of the fiber.
• As these dyes are insoluble or only slightly soluble in water,
they are applied from an aqueous dispersion in the presence of
a dispersing agent.
• They require slight acidity for their exhaustion into the fiber.
The acidity is achieved by adding acetic acid (pH of 4.0–4.5).
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13. Characteristics
● Resists abrasion.
● Very resilient (springs back into shape)
● Resist wrinkling
● Very high heat can “melt” the fabric
● The right amount of heat can be used to permanently
“heat set” a crease.
● Easy to wash and wear.
● Does not absorb water. (can be uncomfortable when
worn next to the skin in warm weather unless loosely
woven)
● Dries quickly.
● Attracts static electricity which also attracts dirt and lint.
● Although they do not absorb water, they do absorb oil
and grease.
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14. Advantages and Disadvantages
● The fabrics made from polyester fiber have
● good elasticity,
● wrinkle resistance,
● shape retention,
● excellent wash-and-wear performance
● durability, and so on
● so that it is widely used in all kinds of apparel
fabrics.
● However, because polyester fibre is poor in
moisture absorption, its clothing makes the wearer
feel hot and sticky, produces static electricity easily
which results in clothing absorbing dust and
clinging to the body, and has poor comfort.
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16. Uses of Polyester
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18. Thanks to all
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