Manmade filaments & textured yarn_Dr.Ash

Presentation by
Dr. S. Aishwariya
INSPIRE Fellow (DST) and Assistant Professor,
Department of Textiles and Clothing
Avinashilingam Institute for Home Science and Higher Education for Women,
Coimbatore, TN, India.

Man-made filament yarn processing –
Dry, Wet and Melt
Textured yarns
Stretch – false twist
Modified stretch – knit-deknit
Bulk – gear, stuffer, air jet

Each hole in the spinneret will create one filament that
will not touch another filament
Chips like medium is used in making the filament - polymers

 Polymers are the basic raw materials in making man made filaments.
 Polymers are fiber forming substance that gets melted in dope (vessel)
 Just like fibre science and yarn science, polymer science is a subject
that deals exclusively with man made filament MANUFACTURING
The man made filaments are made by three techniques
1. Dry spinning – dry air is used to solidify the solvent
2. Wet spinning – dissolved and extruded in chemical bath (wet)
3. Melt spinning – polymer melted – cooled - solidified

Instead of precipitation of
polymer, solidification is
achieved by evaporating the
solvent in dry air/ gas
Eg: Acetate, triacetate,
acrylic, modacrylic,
spandex and Vinyon

Polymer is dissolved in chemical bath and extruded in another
chemical bath
Eg: Acrylic and Viscose rayon

Polymer is melted and
forced through cooling air
to solidify
Eg: Nylon, polyester,
saran, glass and olefin

Man made filaments are flat and boring.
MMF are mostly thermoplastic (heat-sensitive)
in nature
The heat sensitive inherent nature of the Man
made filaments are used to change the surface from
flat to textured (wavy, curved, crimped)
Texturizing is a process in which the surface of
the yarn is given crimp (curl/wavy)
Why do?
to change the surface of the filament yarns
to make yarn resemble natural fibers
increase absorbency and warmness property

MERITS AND DEMERITS OF TEXTURED YARNS
Advantages
•
Higher bulk (weight)
•
Greater water absorption (loop)
•
Increased warmth (heat retention)
•
Good draping capacity (structured)
•
Better air permeability (gaps)
•
Better dimensional stability (elasticity-like curly hair)
•
Higher covering power (recovering)
•
Higher hygienic characteristics (microorganisms wont have base to live)
•
Pleasing hand and appearance (texture)
Disadvantages
•
Increased hairiness
•
Reduced strength (processing)
and abrasion resistance

❶ False-twist coiling method
❷ Stuffer-box crimping method
❸ Air-jet texturing method
❹ Knit-de-knit crinkling method
❺ Gear crimping method
Methods for creating textured yarns
Stretch yarns
Bulk yarns (Bulk CF yarn)
Modified Stretch
CF – continuous filament yarn

Stretch yarns Bulk yarns
Modified
Stretch

❶ Stretch yarns:
•These are used in stretch to fit garment
•Swimsuits, lingerie, stockings, one-sized
garments where a form-fitting resilience
without pressure is required
•Elastic extensibility can be up to 400%
•Moderate bulk and helical crimpiness
•Method to create stretch yarn
1. False twist
2. Edge crimp

• The lap of fibre is passed through drafting rollers and twisted.
• An attachment seen next to it is used to untwist the twist.
• The resultant yarn looks with a crimp/waviness like that of a
natural fibre
False twist

Filament yarn is heated and
pulled across a knife at an
acute angle.
When the yarn is cooled and
released it retains a spring or
curled ribbon appearance, i.e.
the profile is heat-set

❷ Modified stretch yarns:
Yarns are used in shirting and suits
•Moderate level of stretch (10-15%)
•High bulk
•helical or planner crimpiness
In knit-de-knit (knit and remove knit) the yarn is knit into a
tube and heat set.
Yarn is then unravelled, in which it retains the looped structure
(like we do in a socks).
The resultant yarn will be in a loop like pattern – a curl
texture of a knitted yarn

❸ Bulk yarn:
Yarn in shirts and suits, carpet yarns, sweater
•Increased bulk
•Little or no stretch
•Loopy structure and common extensibility
•Method to make bulk yarn
1. Gear crimping
2. Stuffer box
3. Air jet method

• When yarn is sent at a rapid speed and
extruded at a lower speed, the yarn coils inside
the box, resulting in a coiled bulk yarn.
• When pressurised air is passed inside the
filaments entry, the messed up coiled texture
creates bulk
• After the above process, heat set is given to
retain the texture.

The heated filament when
passed between the gears,
the tooth design is transferred
onto the filament, resulting in
a bulk yarn (textured yarn)
Heat set is done later

Stuffer box Filaments pass through a
heated box, but are fed into
it faster than their removal
rate – i.e. an overfeed.
This forces them to adopt a
random wavy crimped
pattern while heated;
subsequent cooling sets
their textured form.

In Air jet texturizing –Overfeeding of filaments at high speed into a chamber
creates a bulk.
Instead of using heat to facilitate the texture profile, compressed air is blown into
the chamber and this causes the loose lengths of the filaments in the yarn to spread
apart and form entangled random loops. Later heat set

BICOMPONENT FIBERS
•It is composed of two different polymers joined
physically in a single filament.
•The components can be joined side by side or in a
sheath-core structure.
•Due to chemical differences of the components each
shrinks to a different degree when exposed to certain
conditions such as heat or moisture.
•The difference in shrinkage causes a pulling of the
yarn into a crimped conformation creating bulk and
texture.

Manmade filaments & textured yarn_Dr.Ash

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