The document discusses the fiber manufacturing process. There are two types of manufactured fibers: regenerated and synthetic. The fiber spinning process involves three main steps: 1) preparing a viscous dope or melt, 2) forcing the dope or melt through a spinneret to form fibers, and 3) solidifying the fibers through coagulation, evaporation or cooling. Polyester is one of the most widely used synthetic fibers and is made from polymers containing ester functional groups. It is strong, durable, wrinkle resistant and can be blended with other fibers like cotton and wool.
2. the fiber manufacturing process
manufactured 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
4. 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 melt
2.forcing or extruding dope or melt through opening in
spinneret to form a fiber
3.solidifying the fiber by coagulation, evaporation or
cooling
9. 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 fibe
12. 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 fibe
13. 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
22. 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..
23. 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.
24.
25. 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 fibe
This time, when the filaments dry, the fibers become soli
and strong instead of brittle.
• Drawn fibers may vary greatly in diameter and length, Als
as the fibers are drawn, they may be textured or twisted t
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.
26.
27. 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.