Reader 2: Filament yarns and texturing
Background information
First man-made filament fiber = rayon (1890)
Other examples of filament yarns: nylon, polyester, polyacrilics, polyolefins, polyurethane.
Used as filaments in filament yarns. Exception: acrylic and modacrylic (used in staple form).
Filament yarns 1+ continuous filaments and assembled with or without twist.
Uses
Carpeting, industrial textile products, underwear, outerwear.
Filament:
1. Flat
2. Textured
a. False twist
b. Air jet
c. Bulk
d. Other (gear crimp, stuffer box)
Different types of yarns
Flat continuous filament yarns:
1. Monofilament: 1 continuous filament. Ex: fishing line.
2. Multifilament: yarn is composed of multiple filaments brought together.
Textured continuous filament yarns: formed using continuous filaments that have been
modified. To give bulk/ stretch properties.
Spun yarns: formed using short or non-continuous fibers.
1. Short staple spun yarns: using fibers less than 2.5 inches long
2. Long staple spun yarns: using fibers from 2.5 up to 18 inches long.
Flat multifilament yarns
- Smooth and compact fabric surface
- Typically round cross-sectional shaped fibers
,Cross-sections and effect on fabric
Shape Name Luster Flexibility Coverage
Round Reflects
+ +
Octobal Reflects a lot
+ _
Trilobal
- _
Cross section Function
Hollow Insulation and wicking
Clover Bulk
Octobal Glitter reduction
Multi-channel Bulky micro-denier yarns
Trilobal Luster
Modification ratio = aspect ratio = changing the inner and outer diameters of a trilobal
fiber.
Yarn luster
Bright, semi dull, dull (matte) or full dull.
Titanium dioxide creates a dull luster. Leads to high friction on surface of fabric.
Round cross section + low amount dulling agent = metallic yarn.
Trilobal cross section + low amount dulling agent = silk luster.
High and low luster filament yarns can be used in combination with each other.
, Filament yarn manufacturing steps
1. Filament is extruded (as mono- or multi-filament)
2. Filament is drawn (stretched)
3. Yarn is wound onto packages
4. Yarn is twisted, re-packaged or plied.
5. Yarn can be flat or textured.
(Filament yarns containing thermoplastic fibers can be heatset to different degrees to
produce yarns with high stretch and/or bulk)
Filament extrusion
Extrusion: a polymer solution is forced through the holes of a spinnerette.= Spinning
The spinnerrette hole size determines the filament denier or dPF.
Slit film yarn extrusion: polymer film (polyolefin) is extruded and then cut into narrow
strips.
1. Extruded film is drawn by draw rollers
2. Passes a slitter/embosser
3. Slit yarns are placed on a spool
4. Spools of yarn are woven
Spinning:
1. Melt spinning: melting polymer chips before extrusion. (Nylon, polyester, olefin).
2. Dry spinning: using a solvent to dissolve the solid polymer material and then re-
solidifying the polymer. (some rayon fibers)
3. Wet spinning: solidifying the extruded polymer in a wet bath. (some rayon
fibers)
Man-made staple fibers originally were in the form of continuous filaments before going
through a cutting process. Tow: a lot of extruded filaments that form a bundle of fibers.
- Tow is cut into staple fibers
- Staple fiber is formed into a spun yarn that is a 100% yarn
- Or blended with other staple man-made fibers
Drawing
1. Molecular structure long polymer chains are randomly arranged.
2. Drawing
3. Yarn size/thickness decreases.
4. Yarn becomes more stable.
5. At a certain point the polymer chains are crystalline.
Yarn orientation for texturing
Yarn orientation: arranging the polymer chains in filament yarns to a more organized and
parallel arrangement. Draw ratio can be calculated from the velocity ratio of the 2 rollers.
FOY = fully orientated yarn FDY = fully drawn yarn
POY = partially orientated yarn cheaper than FOY
UOY = un-oriented yarn LOY = low orientated yarn
Background information
First man-made filament fiber = rayon (1890)
Other examples of filament yarns: nylon, polyester, polyacrilics, polyolefins, polyurethane.
Used as filaments in filament yarns. Exception: acrylic and modacrylic (used in staple form).
Filament yarns 1+ continuous filaments and assembled with or without twist.
Uses
Carpeting, industrial textile products, underwear, outerwear.
Filament:
1. Flat
2. Textured
a. False twist
b. Air jet
c. Bulk
d. Other (gear crimp, stuffer box)
Different types of yarns
Flat continuous filament yarns:
1. Monofilament: 1 continuous filament. Ex: fishing line.
2. Multifilament: yarn is composed of multiple filaments brought together.
Textured continuous filament yarns: formed using continuous filaments that have been
modified. To give bulk/ stretch properties.
Spun yarns: formed using short or non-continuous fibers.
1. Short staple spun yarns: using fibers less than 2.5 inches long
2. Long staple spun yarns: using fibers from 2.5 up to 18 inches long.
Flat multifilament yarns
- Smooth and compact fabric surface
- Typically round cross-sectional shaped fibers
,Cross-sections and effect on fabric
Shape Name Luster Flexibility Coverage
Round Reflects
+ +
Octobal Reflects a lot
+ _
Trilobal
- _
Cross section Function
Hollow Insulation and wicking
Clover Bulk
Octobal Glitter reduction
Multi-channel Bulky micro-denier yarns
Trilobal Luster
Modification ratio = aspect ratio = changing the inner and outer diameters of a trilobal
fiber.
Yarn luster
Bright, semi dull, dull (matte) or full dull.
Titanium dioxide creates a dull luster. Leads to high friction on surface of fabric.
Round cross section + low amount dulling agent = metallic yarn.
Trilobal cross section + low amount dulling agent = silk luster.
High and low luster filament yarns can be used in combination with each other.
, Filament yarn manufacturing steps
1. Filament is extruded (as mono- or multi-filament)
2. Filament is drawn (stretched)
3. Yarn is wound onto packages
4. Yarn is twisted, re-packaged or plied.
5. Yarn can be flat or textured.
(Filament yarns containing thermoplastic fibers can be heatset to different degrees to
produce yarns with high stretch and/or bulk)
Filament extrusion
Extrusion: a polymer solution is forced through the holes of a spinnerette.= Spinning
The spinnerrette hole size determines the filament denier or dPF.
Slit film yarn extrusion: polymer film (polyolefin) is extruded and then cut into narrow
strips.
1. Extruded film is drawn by draw rollers
2. Passes a slitter/embosser
3. Slit yarns are placed on a spool
4. Spools of yarn are woven
Spinning:
1. Melt spinning: melting polymer chips before extrusion. (Nylon, polyester, olefin).
2. Dry spinning: using a solvent to dissolve the solid polymer material and then re-
solidifying the polymer. (some rayon fibers)
3. Wet spinning: solidifying the extruded polymer in a wet bath. (some rayon
fibers)
Man-made staple fibers originally were in the form of continuous filaments before going
through a cutting process. Tow: a lot of extruded filaments that form a bundle of fibers.
- Tow is cut into staple fibers
- Staple fiber is formed into a spun yarn that is a 100% yarn
- Or blended with other staple man-made fibers
Drawing
1. Molecular structure long polymer chains are randomly arranged.
2. Drawing
3. Yarn size/thickness decreases.
4. Yarn becomes more stable.
5. At a certain point the polymer chains are crystalline.
Yarn orientation for texturing
Yarn orientation: arranging the polymer chains in filament yarns to a more organized and
parallel arrangement. Draw ratio can be calculated from the velocity ratio of the 2 rollers.
FOY = fully orientated yarn FDY = fully drawn yarn
POY = partially orientated yarn cheaper than FOY
UOY = un-oriented yarn LOY = low orientated yarn
