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Man-made or Synthetic fiber production technology. I am trying to give a primary knowledge on the production technology of man-made fibers.
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Presentation
ON
The Production Technology Of
Man-Made Fibers
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Md. Yousuf Hossain.
ID No. : 120103063
Department Of Textile Engineering
Green University Of Bangladesh
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
e.g. : 1. Rayon (Wood/ Bamboo)
2. Polyester (Petrochemicals)
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Classification flowchart of man-made fibers
Man-Made Fibres
Inorganic
By transformation of natural polymer
From synthetic polymer
Acrylic = PAN
Aramid = AR
Chlorofiber =CLF
Elastane = EL
Elastolefin = EOL
Elastodiene = ED
Elastomultiester =
EME
Polyamide = PA
Polyester = PES
Polyethylene =PE
Polyimide = PI
Polylactide = PLA
Polypropylene = PP
Vinylal = PVAL
Fluorofiber = PTFE
Modacrylic = MAC
Carbon = CF
Ceramic = CEF
Glass = GF
Metal = MTF
Aliginate =ALG
Acetate = CA
Cupro = CUP
Lyocell = CLY
Modal = CMD
Viscose = CV
Triacetate =CTA
Elastodiene =ED
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
How can we get man-made fibers?
Man-made fibers are produced from polymers.
These substances are solids at normal temperatures in the form
of chips or small particles.
The polymers in solid form must be converted to fluid form as
the polymer needs to be forced through the spinneret holes to
form filaments.
Solidify fibers by cooling or evaporation or coagulation.
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
The polymer processing from the solid to the fluid state can
take place with two methods-
I. By Melting. (This method is used for 70% of the fibers)
II. By Solution. (This method is used for 30% of the fibers)
i. Dry Spinning
ii. Wet Spinning
iii. Gel Spinning
The method is used for each fiber depends upon the easy
conversion process of the polymer from solid to fluid state.
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Melt Spinning:
The polymer is melted and pumped through a spinneret with
numerous holes (one to thousands). The molten fibers are cooled,
solidified, and collected on a take-up wheel.
Polymer converted to fluid just by heating.
Simplest process used for Polyester, Polyamide, Polyethylene,
Polypropylene and Glass fibers.
High Speed ( up to 10000 m/min)
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Required characteristics of fiber for Melt Spinning:
Fibers must melt without decomposition and be stable to at
least 30 degree higher than its melting temperature.
Mobility in the molten polymer is necessary to be
extruded.
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Stages in Melt Spinning Process
At first, Heat the polymer.
Then, Extrusion through the spinneret (50mm in diameter) having fine holes of 0.5mm diameter.
Cool and solidify the filament.
Then, the solidified filaments are passed around a rotating roller and forwarded to a collecting roller.
Features Of Melt Spinning:
Melt-spun fibers can be forced through the spinneret in different
cross-sectional shapes such as round, tribal etc. Which give
different qualities to the fabric.
Do not have toxic hazard.
No solvent and purification problem.
The Production Technology Of Man-Made Fibers
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Figure 1 : Melt Spinning
Dry Spinning
If Polymer is getting chemically damaged by heating but it
can be dissolved in a suitable volatile solvent which later
on evaporates.
The Production Technology Of Man-Made Fibers
Speed = 1000 m/min.
Used for production of Acrylic, Modacrylic, Acetate, Triacetate,
Spandex/Elastane.
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Merits Of Dry Spinning:
Yarn does not required purification.
Demerits Of Dry Spinning:
The obvious limitation for this method is that it depends on the
existence of volatile solvent for the polymer.
Solvents are expensive, flammable and explosive in reaction
with air.
3-6 kg solvent is needed for 1kg filament.
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Wet Spinning
If the polymers cannot be melted by heating or dissolved in
volatile solvent then wet spinning is used.
The spinneret is submerged in a chemical bath that leads the
fiber to precipitate and solidify as it comes out of the spinneret
hole.
Polymer is dissolved in a non-volatile solvent.
This is a slow process (speed=200 m/min)
Used for production of Viscose, Modal, Lyocell, Aramid fibers. Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Figure 3 : Wet Spinning Process
Merits Of Wet Spinning:
Suitable for tow production.
Demerits Of Wet Spinning:
Cumbersome technology.
Purification of the filaments is needed.
Environment pollution hazards.
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Gel Spinning:
In gel spinning the filaments first pass through air and then are
cooled further in a liquid bath. Here polymer is partially liquid or
in a gel state, which keeps the polymer chains somewhat bound
together leading to greater tensile strength.
Used for production of high strength PE and aramid fibers.
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Figure 4 : Gel spinning process.
Advantages of Gel spinning:
Medium speed (up to 1500 m/min).
Suitable for liquid crystalline polymers.
Disadvantages of Gel Spinning:
Environmental pollution hazards.
Purification of the filament is needed.
Cumbersome technology.
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Comparative features of Melt, Dry and Wet Spinning
Features Melt Dry Wet
Investment Cost Low High Low
Toxic Hazard Non-toxic Toxic &
Risk of explosion
Toxic
Heat of Spinning High High Low
Spinneret Hole Two to thousand 300 - 900 20,000 - 75,000
Spinning Speed 1500 - 6000 m/min 1000 - 1500 m/min 200 - 300 m/min
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Manmade fibers can be modified at any stage-
During production- e.g. Additives (Delustrant, heat &
light stabilizers)
Immediately after production. e.g. Spin Finish
(Lubricants, plasticizers)
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]
Any Question?
1………………………………………………………..?
2………………………………………………………..?
3………………………………………………………..?
Md. Yousuf Hossain, Green University Of Bangladesh, [email protected]