the fiber manufacturing processmanufactured fiber—any fiber derived by a process of manufacture from a substance that at any point in the process is not a fiber•generic names—refers to family of manufactured or synthetic fibers with similar chemical composition•trade names—companies’ names for fibers used for promotion & marketing

two types of manufactured fibers—•regenerated•synthetic

impact has far exceeded original predictions—caused tremendous changes in the way people live

the fiber manufacturing process

fiber spinning

raw material is:•natural product—cellulose or protein•synthetic polymer dissolved in liquid chemicals and made into a spinning solution (dope)

all manufactured-fiber spinning processes are based on these 3 steps:1.preparing a viscous dope or melt2.forcing or extruding dope or melt through opening in spinneret to form a fiber3.solidifying the fiber by coagulation, evaporation or cooling

fiber spinning

fiber spinning

fiber spinning

Definition

• Polyester (aka Terylene) is a category of polymers which contain the ester functional group in their main chain.

Polyester is currently defined as:

“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.

Forms Of Polyester

1. Filament

2. Staple

3. Tow

4. Fiberfill

Definition

• Polyester (aka Terylene) is a category of polymers which contain the ester functional group in their main chain.

Polyester is currently defined as:

“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.

Uses Of Different Form In Different Places

1. In the filament form, each individual strand of polyester fiber is continuous in length, producing smooth-surfaced fabrics

2. In staple form, filaments are cut to short, predetermined lengths. In this form polyester is easier to blend with other fibers

3. Tow is a form in which continuous filaments are drawn loosely together

4. Fiberfill is the voluminous form used in the manufacture

of quilts, pillows, and outerwear

Microscopic View

Different Structures Of Polyester

synthetic fibers—properties of polyester

aesthetics—blend well, maintaining natural fiber look & texture; microfibers particularly suited to high-fashion because of versatility & durability

durability—excellent abrasion resistance & strength; better sunlight resistance

comfort—poor absorbency lowers comfort factor; finishes & fiber modifications increase comfort

appearance retention—generally wrinkle resistant except when set by body heat and moisture

care—wash warm, machine dry medium heat, remove promptly, hang, touch up with steam

synthetic fibers—polyester uses

most widely used MF in US

•woven fabrics in apparel & interiors•knitted fabrics •fiberfill•nonwoven or fiberweb fabrics•tirecord•carpets•technical hoses, belts, •artificial arteries, veins & hearts

Polyester Blends

• Polyester and Cotton1. Resist wrinkles2. Resist stains3. Retain shape

Polyester Blends

• Polyester and Wool1. Wrinkle resistance2. Shape retention3. Increase durability

Polyester Blends

• Polyester and Wool1. Wrinkle resistance2. Shape retention3. Increase durability

Manufacturing Filament Yarn

• Polymerization• Drying• Melt spinning• Drawing the fiber• Winding

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• After the polyester emerges from polymerization, the long

molten ribbons are allowed to cool until they become brittle..

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.

• 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.

Chemical properties

• Acids: At room temperature, PET is resistant to organic and• moderate strength mineral acids. At high temperatures, PET • strength loss in moderate strength acids can be appreciable. • Strong acids such as concentrated sulfuric acid dissolve and • depolymerize PET.• Alkalies: Polyester fibers have good resistance to weakly alkaline• chemicals and moderate resistance to strongly alkaline chemicals• at room temperature. PET fibers are attacked by strongly alkaline• substances.• Organic Solvents: PET fibers are generally insoluble in organic • solvents, including cleaning fluids.