Elastomeric Fiber

1. Elastomeric Fiber

2. Elastomer :
 An Elastomer is a polymer with the physical property
of elasticity. Elastomer is a term derived from elastic
polymer, which is often used interchangeably with the
term rubber. Each of the monomers which link to from
the polymer is usually made of carbon, hydrogen,
oxygen and/or silicon. Elastomers are usually
thermosets requiring a curing process of rubber
involving heat and the addition of sulfur or other
equivalent curatives. In addition elastomers might also
be thermoplastic.

3. Elastomeric Fibers
Elastomeric fibers are those fibers that possess
extremely high elongations (400%-8001) at break and
that recover fully and rapidly from high elongations up
to their breaking point. Elastomeric fibers include the
crosslinked natural and synthetic rubbers, spandex
fibers (segmented polyurethanes), anidex fibers
(crosslinked polyacrylates) and the side-by-side
biconstituent fiber of nylon and spandex (Monvelle).

4. 
Fig-1:Elastomeric Fibers

5. The spinning Process
 When the two types of pre-polymers are mixed
together, they interact to form the spandex fibers. In
this reaction, the hydroxyl groups (-OH) on the macro
glycols react with the isocyanides. Each molecule gets
added on to the end of another molecule, and a long
chain polymer is formed. This is known as a step-
growth or addition polymerization. To initiate this
reaction, a catalyst such as diazobicyclo octane must
be used. Other low molecular weight amines are added
to control the molecular weight of the fibers.

6. Fig-2: Spinning process of elastomeric fiber

7. Physical properties of elastomeric
fiber (spandex)
 Tenacity : 037gm/den
 Density : 1.21-1.35
 Elongation at break : 400-700%
 Elasticity : Excellent
 Moisture regain : 0.6%
 Resiliency : Very good
 Ability to protest friction : Excellent
 Color : White or near white
 Luster : Less bright

8. Chemical properties of
elastomeric fiber
 Acids : It has preventive power against all of the acidic
action.
 Basic : Hot alkali damages the spandex filament.
 Effect of bleaching : Bleaching agent damages the fibre and
it becomes weak.
 Protection ability organic solvent : Good.
 Protection ability light : Very good
 Protection ability against mildew : Good
 Protection ability against insects : It doesn’t affected by
insect.
 Dyes : Disperse dyes , acid dye is suitable to dye spandex
filament,

9. Preparation of the elastomeric fibers
 The preparation process of the elastomeric fibers is
illustrated in Fig.3. Firstly, the prepared spinning
dopes were stored in a container with piston and
pressed very slowly into a artificial duct (about
500 μm in inner diameter, and about 12 cm in
length). Secondly, the spinning dopes went
through the duct and flowed into the pure tap-
water in a glass water tank, immediately
solidifying and spontaneously rising to form the
initial fibers.

10. Fig-3: preparation of elastomeric fiber
o

11.  Thirdly, after the initial fibers freely rose from
underwater to water surface and stayed for about 3 min
in the tap-water, they were taken out of the water tank
and received vertical stretching up to 5–6 times of the
initial length in another water tank full of tap-water or
air, and after the vertical stretching was kept for about
40 min, the stretched fibers were prepared. Fourthly,
the stretched fibers were placed in a vacuum oven to
be dried for about 12 h at 45 °C under vacuum, and the
final fibers were produced. After the initial helical
fibers were taken out of the tap-water, they were
directly dried in the same conditions without vertical
stretching, and the final helical fibers were also made.

12. Various other types of elastomers:
 Thermoplastic elastomers (TPE)
 The proteins resilin and elastin
 Polysulfide rubber
 Elastolefin, elastic fiber used in fabric productio

13. Application of elastomeric fiber
 1.Apparel
 Athletic apparel , swimwear, underwear ,lingerie, foundation
garment, hosiery ,normal
clothing,belts,skipanty,slacks,socks,tubular knit fabrics for
ladies, and, warp knit fabrics for ladies, warp knit fabrics for
corsetry and sundry applications
 2.Automotive
 Body fasteners, electrical boots, suspension system parts, seals
and gaskets, belts, taillight assemblies, battery covers, hoses,
covers for electronics, adhesives, bushings, bump stops,
interlayer for laminates, air bag covers,transmission boots.
 3.Adhesives and Sealants
 Shoes, laminated security glazing, aerospace, marine, magnetic
media binders, construction.

14.  4.Coatings
 Floor, roof, wire and cable, fiber optics, waterborne,
radiation curable, fabric, aircraft, pipe, concrete, vinyl.
 5.Engineered Components
 Gears, sprockets, printer rolls, belts, wheels, fork lift tires,
escalator wheels, heavy-duty casters.
 6.Industrial
 Lined pipe, water valves, pump impellers, hopper car liners,
conveyor belts, grain buckets, grain chute liners,marine
bumpers, buoys, marine hoses, mining screens, cyclone
liners, cattle tags.
 7.Sports
 Roller wheels, ski boots, bicycle tires, horseshoes, athletic
shoes.
 8.Home furnishing
 Micro-bend pillows

15. Polyethylene Fiber
A manufactured fiber made of polymerized
polyethylene units. It is often a monofilament, but
is also available as continuous filament yarns and
as staple fiber. Polyethylene is a polymer. Many no.
of ethylene monomers join with each in the
synthesis of polyethylene polymer. Polyethylene
yarn cannot be dyed. It is colored by the addition
of pigments and dyes to the melt at extrusion.
Polyethylene can be created in several different
forms.

16. Polyethylene

17. Chemical composition and molecular structure:
 Ethylene (C2H4) is a gaseous hydrocarbon commonly
produced by the cracking of ethane, which in turn is a
major constituent of natural gas or can be distilled
from petroleum. Ethylene molecules are essentially
composed of two methylene units (CH2) linked together by
a double bond between the carbon atoms—a structure
represented by the formula CH2=CH2. Under the influence
of polymerization catalysts, the double bond can be broken
and the resultant extra single bond used to link to a carbon
atom in another ethylene molecule. Thus, made into the
repeating unit of a large, polymeric (multiple-unit)
molecule, ethylene has the following chemical structure: .

18. Ethylene Polyethelyn polymer
Molecular structure of polyethelyne fibre

19. Spinning process of polyethylene fiber
 Spinning of polyethylene is carried out by
melt spinning. The polymer with a
molecular weight of about 15,000 is spun
from the melt at about 205 deg C and
extended through a spinnerets of 0.1 mm
diameter into a current of cooling gas. The
filaments are cooled to 15 -60 deg C and
stretched 4 to 10 times their original length.
The drawn monofilaments are wound on
spools

20. Fig-2: Spinning process of polyethylene fiber

21. Properties of Polyethylene Fiber
 1. Polyethylene fibre has a round cross section and has a smooth
surface. Fibres made from low molecular weight polyethylene
have a grease like handle.
2. The moisture regain of polyethylene is practically nil and
hence moisture does not affect the mechanical properties of the
fibres.
3. Higher energy is needed to break because of specific modulus
and high specific strength
4. Polyethylene is insoluble in most of the common organic
solvents at room temperature.
5. Polyethylene fibres have a high degree of resistance to acids
and alkalies at all concentrations even at high temperature.

22. 6. Very good ultra violet resistance
7. The fibre is generally inert and is resistant to wide range of
chemicals at ordinary temperatures. They are attacked by
oxidising agents.
8. Excellent electrical and chemical resistance
9. Very good abrasion resistance
10. Other Properties
•Specific Gravity- 0.92
•Tenacity - 1.0-1.5 gpd
•Elongation at Break %- 45-50
•Tensile Strength psi - 15000
•Softening Range: deg C- 85-90

23. Application of Polyethylene
 Medical implants
 Cable and marine ropes
 Sail cloth
 Composites like Pressure vessel boat hulls, sports equipment,
impact shields
 Fish netting
 Concrete reinforcement
 Protective clothing
 Can be used in radar protective cover because of its low dielectric
constant
 Can be used as a lining material of a pond which collects
evaporation of water and containment from industrial plants
 Useful in geotextile applications

24. Conclusion
The preparation of a nanofiber membrane of an elastomer was
successful using the electrospinning process. The diameter of the
fiber is dependent significantly on solution concentration, voltage,
distance and the viscosity of the polymer. Beadless nanofiber
membrane that consisted of polybutadiene was obtained under the
condition of 5.25wt%, 25KV, and 5cm. The mean diameter of the
fiber was 0.46 µm. In addition, it was found that fibers without
beads were obtained by growing the multi-cone in the needle tip. It
was possible to co-electrospin VGCF or VGNF with the elasotomer.
The viscosity and electrical conductivity of the polymer increased
with the addition of VGCF/VGNF. The tensile strength of the
elastomeric nanofiber membrane was similar to that of the film.
However, the initial elastic modulus was very low. A soft feeling
elastomer nonwoven membrane was obtained

25. The End

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