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REPORT
POLYPROPYLENE FIBRE

TABLE OF CONTENTS
TITLE PAGE Page
TABLE OF CONTENTS
ABSTRACT
CHAPTER 1: INTRODUCTION
1.1 BACKGROUND 1
1.2 HISTORY 1
1.3. ORIGINS OF CRYSTALLINE POLYPROPYLENE 2
1.4. BASIC DESCRIPTION OF POLYPROPYLENE 2
CHAPTER 2: STRUCTURE
2.1. STRUCTURE OF POLYPROPYLENE FIBER 3
CHAPTER 3: MANUFACTURING OF POLYPROPYLENE FIBRE
3.1 INTRODUCTION 5
3.2 i-Gas-Phase Technology (Fluidized-Bed Reactor): 5
3.3. ii- Bulk-Phase Technology 6
3.4. MANUFACTURING OF THE FIBRE: 7
- Short Air-Quench Melt-Spinning 7
- Long Air-Quench Melt-Spinning 8
- Spin-Draw Process 8
- Spin-draw texturing process 9
- Water-quench melt-spinning process 9
- Tape-Yarns from Slit Film 10

CHAPTER 4: PROPERTIES OF POLYPROPYLENE FIBER
4.1. DYEING: 10
4.2 PHYSICAL PROPERTIES 11
4.3 CHEMICAL PROPERTIES 12
CHAPTER 5: ADVANTAGES AND DISADVANTAGES
5.1. ADVANTAGES 14
5.2. DISADVANTAGES 15
CHAPTER 6: APPLICATIONS
6.1. APPLICATIONS 16
CHAPTER 7: CONCLUSIONS AND RECOMMENDATIONS
7.1 CONCLUSIONS 17
7.2 RECOMMENDATIONS 17
REFERENCES 18

ABSTRACT
Belts made of various materials have been in use since ages. People are always
looking for strengthening and durable belts that really do last longer. But how can we
know that which fiber suits the best to make a belt which we can lift heavy loads without
the fear of breakage. For this purpose a synthetic fibre, polypropylene, is used.
The principal reason for using PP fibres into a belt is to reduce breaking in the elastic
range, increase the tensile strength and deformation capacity and decrease the
toughness of the resultant composite. These properties of Polypropylene fibres depend
upon length and volume of propylene fibres (PPF) used. This report takes into account,
the belt made from polypropylene fiber is best to make belts as its properties
complements our requirements. One of the major benefits of Polypropylene is that it can
be manufactured into a living hinge. Polypropylene is uniquely adept for living hinges
because it does not break when repeatedly bent. Polypropylene is normally tough and
flexible.
Polypropylene is reasonably economical that is also why polypropylene belt is given
preference when in need than a belt made of any other fiber. It can be made translucent
when uncolored, but is not as readily made transparent as polystyrene, acrylic, or
certain other plastics. It is often opaque or colored using pigments. The belt can also be
majorly used as conveyer belts as polypropylene has good resistance to fatigue. Our
article is a belt made of high tenacity polypropylene and it can be white or gray
personalized with white, gray, yellow, red, blue and green lines; this is the normal type
of the series, the first type of belt woven with synthetic fibers; a belt which has made
history.

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INTRODUCTION
1.1. BACKGROUND
Textile is a very vast field, we are surrounded by textile. From clothing to household,
textile is everywhere. While textile helps us in clothing it also plays a vital role in other
fields like medical, automobiles and much more.
Textile also has its value in making small important articles which we use almost on
daily basis. These small articles include Bags, apparel, mats, belts, coverings etc. Belts
are very useful which are used to carry heavy loads of boxes easily. Historically, most
designs have been made of leather or other natural materials. Current technologies
allow synthetic polymers such as polypropylene to replace natural materials - these can
easily be molded or woven, and made in exotic colors or even translucent.
Polypropylene is manufactured in various forms on 6 continents and its applications are
ubiquitous in daily life, from the fiber in your carpets and the upholstery in your living
room furniture to the casings for the power tools in your garage.
1.2. HISTORY
Crystalline polypropylene was discovered in the early 1950s and commercial production
began in 1957 in Italy, Germany and the USA. Since that modest beginning,
polypropylene has become among the most important synthetic polymers produced by
human kind, ranking second only to polyethylene.

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The history of crystalline polypropylene (PP) is nevertheless unique from several
standpoints:
i) Polypropylene was the first high melting crystalline aliphatic hydrocarbon.
ii) PP has been the subject of perhaps the most scientific research and printed
matter of any crystalline polymer.
iii) Crystalline polypropylene is the only hydrocarbon polymer impacting on a noble
prize.
Polypropylene is classified as the youngest of the largest and fastest-growing
thermoplastics in the market place today. The rapid growth of polypropylene is due to its
versatility, wide applicability, and low cost.
1.3. ORIGINS OF CRYSTALLINE POLYPROPYLENE
Crystalline polypropylene (PP-) was unknown to the world before the 1950s.
Thougholigomeric and polymeric forms of propylene had been made before that time,
they were typically amorphous, low molecule weight oils.
These liquid/oily polymers were produced by polymerization or oligomerization of
propylene using free radical initiators or acidic/cationic catalysts at high temperature
and pressure and were of marginal commercial value.
1.4. BASIC DESCRIPTION OF POLYPROPYLENE
Propylene (aka propene) has molecular formula C3H6. Other than ethylene, it is the
simplest alkene. Propylene may be polymerized through the action of catalyst. A recent

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analysis suggests that polypropylene is the single largest volume plastic produced
globally.
STRUCTURE
2.1. STRUCTURE OF POLYPROPYLENE FIBRE
In PP fibers, by contrast, the polymer chains can adopt three different configurations,
also shown schematically in fully extended planar projections.

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In planar projections of isotactic PP chains, all the methyl side-groups are situated
uniformly on the same side of each chain, although in practice the chains adopt a three-
dimensional helical configuration.
In syndiotactic PP chains, the methyl groups regularly alternate between the two sides
of each chain. Syndiotactic PP chains may also adopt a helical configuration.
In the case of atactic PP chains, the methyl groups are arranged randomly on both
sides of each chain.

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MANUFACTURING OF POLYPROPYLENE FIBRE
3.1 INTRODUCTION
The starting material for polypropylene is propylene, which is being produced during the
refining of petroleum or gasoline.
There are two different kinds polymerization process to convert propylene into
polypropylene.
3.2 i- Gas-Phase Technology (Fluidized-Bed Reactor):
In this process, gaseous propylene contacts a solid catalyst in a fluidized-bed reactor.

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Macromolecule that contains from 10,000 to 20,000 monomer units of propylene are
joined together to form homopolymer and random copolymer Polypropylene.
3.3. ii- Bulk-Phase Technology: In this process, liquid propylene contacts a solid
catalyst inside a loop reactor.
In the polymerization step, specialized catalyst is used to produce polymer molecules
that are capable of crystallizing when formed into fibers. The metallocene system is a
newer catalyst introduced by two chemists, Karl Ziegler and Giulio Natta, which is now
also used by several producers. The metallocene system produces purer polymers that
are more uniform in size.
After polymerization the polymer is extruded and cut into pellets, which are shipped as
resin to fiber or film producers. And then it is being carried for the next process that is
the manufacturing of polypropylene fiber.

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3.4. MANUFACTURING OF THE FIBRE:
Polypropylene may be melt spun into fiber filaments for subsequent conversion to
yarns, or laid down in a fiber web to form a nonwoven fabric. Another form, fibrillated
fibers, can be created by first extruding a film of polypropylene. The film is then either
stretched and split or slit and drawn into a network of fibers. But before this all the
polypropylene which is in raw form undergoes different process of melt-spinning that are
discussed below:
a) Short Air-Quench Melt-Spinning
The whole process of spinning is held in small scale, we can say quench zone which is
in general 1m long. The spinning speed in this process is quite low. To increase
productivity of fiber large number of orifices (hole) is made in spinneret that is around
55000.
This method is used for production of high tenacity polypropylene

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b) Long Air-Quench Melt-Spinning
In this method high linear speed technique and a long length of the cooling duct is used
and the rest of the process is same as other melt spinning process.
c) Spin-Draw Process
This method has integrated process of couple spinning and drawing into one continuous
operation. This process is used to produce high tenacity coarser industrial yarn.

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d) Spin-draw texturing process
This is a unique process as it combines spinning, drawing and texturing in one process.
This method is useful for producing bulked continuous filament. The filament is
subjected to a bulking operation by overfeeding the yarn into a hot fluid, they are then
thrown onto cooling drum.
e) Water-quench melt-spinning process
This method is used for the manufacture of heavy denier monofilaments because
cooling is more efficient and after passing though spinneret it enters a water-quench
tank.

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f) Tape-Yarns from Slit Film
Using this method the polypropylene is extruded as film, this film is then drawn
uniaxially and as it fibrillates it is cut into yarns with knives. The yarns produced from
film have higher tenacity levels.
Polypropylene fibers are difficult to dye, it is easier to add pigment colors during
spinning.
PROPERTIES OF POLYPROPYLENE FIBER
4.1. DYEING:
Polypropylene filaments have no polar destinations, as they are to a great degree
hydrophobic and are very crystalline strands in this manner have no affinity for any
class of colors aside from that pale shades can be gotten with a predetermined number
of scatter colors. Numerous systems were attempted to present color substantivity like
utilization of swelling specialists, color solvents and coloring helps however no attractive
outcomes were acquired. Some dyeability is accomplished without much bringing down
of quality of the strands by blending a monomer with the dissolve, instead of the
expansion of a monomer before polymerization. Expansion of a metal complex
compound in the soften grants substantivity in the current colors. The commercial

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applications of polypropylene filaments incorporate floor coverings, car, knitwear and
bundling applications.
4.2. PHYSICAL PROPERTIES:
Moisture regain <0.1%
Refractive index 1.49
Thermal conductivity 0.95 Btu-in/ft2
.hr.F
Heat of fusion 21 cal/g
Coefficient of linear thermal expansion 4.0x10-5
/F
Specific heat 0.46 cal/Gc
Density of melt at 180C 0.769 g/cc
Heat of combustion 19.400 Btu/lb
Oxygen index 17.4
Decomposition temperature range 328-410C
Dielectric constant 0.25
Dissipation factor <0.0002
Specific volume retentivity >1016
ohm.cm
Melting point 165C
Softening point 140C
Elastic recovery (after 30sec at 2% elongation)
Immediate
Delayed
91%
9%
Relative density 0.91 gm/cc
Elongation at break 10-45%
Tenacity 3.5-8.0 gm/den

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4.3. CHEMICAL PROPERTIES:
CREEP:
Polypropylene yarns show more crawl than polyester and nylon yarns, however the sum
is small to the point that it is once in a while of pragmatic hugeness. It is typically
apparently not as much as the ordinary expansion of the yarn under the heap.
DIMENSIONAL STABILITY: FELTING BEHAVIOR:
Polypropylene filaments, as most other engineered strands, don't felt. In mixes with
fleece, Polypropylene decreases the inclination to felt in extent to the measure of
Polypropylene fiber in the mix.
ABRASION RESISTANCE:
Polypropylene filaments have a high scraped spot resistance when dry, and
considerably more prominent resistance when wet. The scraped spot resistance of a
mix containing Polypropylene fiber increments in extent to the measure of
Polypropylene fiber in the mix. Abrasion resistance is of specific significance in
applications, for example, floor coverings, where the capacity to withstand wear is
fundamental.
WASH AND WEAR CHARACTERSTICS: Polypropylene is unusually resistant to
soiling. This is influenced in the main by two factors:
(a) ELECTROSTATIC ATTRACTION: Polypropylene filaments indicate minimal
inclination to amass charges of electricity produced via friction through grinding

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amid utilize. They don't pull in tidy and earth to degree that most other
manufactured filaments do.
(b) CHEMCIAL INERTNESS: Polypropylene is not assaulted by basic solvents, oils,
oils and so forth. It is not promptly recolored and such recoloring as takes put is
ordinarily shallow. The stain is held in the interstices of the texture by fine
fascination and is promptly evacuated by washing and cleaning.
(c) HAND AND DRAPING CHARACTERISTICS: Hand and hanging qualities
depend significantly on weaving and completing of textures.
FLEX RESISTANCE: Recoups well from bowing. Superb low temperature adaptability.
These properties work well for them in rugs and floor covers.
THERMAL CONDUCTIVITY: Polypropylene has the most minimal warm conductivity of
every single business fiber, and in this regard, is the hottest fiber of all.
ELECTRICAL PROPERTIES: Polypropylene is a superb protecting material.
IMPACT OF SUNLIGHT: Like polyethylene, Polypropylene is assaulted by climatic
oxygen and the response is animated by daylight. Polypropylene fiber will disintegrate
on presentation to light, yet it might be secured successfully by methods for stabilizers.
IMPACT OF ACIDS: Excellent imperviousness to most acids with the exception of
chlorosulphonic and concentrated sulfuric corrosive.
IMPACT OF ALKALI: Excellent resistance except for, some oxidizing specialists.
IMPACT OF ORGANIC SOLVENTS: Excellent resistance, for the most part like
Polypropylene. There is no known dissolvable for Polypropylene at room temperature..

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IMPACT OF INSECTS: Polypropylene can't be processed by bugs and related vermin,
for example, white ants, demisted creepy crawlies, silver fish and moth hatchlings.
Polypropylene fiber is not subject to assault unless it turns into an obstruction to past
which the creepy crawly must go to reach and goal. In this cast, the bug must slice
through the fiber without processing.
IMPACT OF MICRO ORGANISMS: Polypropylene won't bolster the development of
mold or growths. Some miniaturized scale living beings however may become even on
the little measures of contaminants which might be available on the surfaces of strands
or yarns being used. Such development has no impact on the quality of any materials
produced using polypropylene.
ADVANTAGES AND DISADVANTAGES
5.1. ADVANTAGES
1. Polypropylene is a light fibre; its density (0.91 g cm
³) is the lowest of all synthetic
fibres.
2. It does not absorb moisture. This means the wet and dry properties of the fibre
are identical. Low moisture regain is not considered a disadvantage because it
helps in quick transport of moisture as is required in special applications like
babies’ ever-dry nappies.
3. Its colors do not fade/or bleed because the dyeing is done by blending color
pigments/master batch with the resin itself prior to fibre extrusion.

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4. It has excellent chemical resistance. Polypropylene fibres are very resistant to
most acids and alkalis.
5. Polypropylene fibres neither support the growth of mildew/fungi nor are attacked
by insects and pests.
6. It is easy to process and ensures high processing yields and profitability. Its cost
is lower than that of polyester and nylon fibres.
7. The thermal conductivity of Polypropylene fibre is lower than that of other fibres
and may be used in applications as thermal wear.
5.2. DISADVANTAGES
1. Polypropylene fibre has low melting temperature, and so requires extra care
during ironing.
2. It cannot be dyed after manufacture. Polypropylene is normally mass colored
before fibre extrusion; a major limitation is the lack of a wide range of shades.
3. Polypropylene has low UV and thermal stability; it requires the addition of
expensive UV stabilizer and antioxidants to overcome the problem.
4. Polypropylene has poor resilience compared with polyester or nylon; higher
denier fibre is, therefore, desirable to overcome this problem.
5. Polypropylene undergoes creep due to its lower Tg(15 to 20C)
6. It melts and burns like wax and is flammable; flame retardants may be added
together with stabilizers.

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APPLICATIONS
Polypropylene has established itself as a very useful industries and household fibre.
However, it has not made a very significant impact in the apparel sector mainly due to
its hydrophobicity, lack of dyeability and a slightly waxy handle. Of late, however, due to
the production of fine denier filaments and textured yarns, it is making in-roads into this
sector as well.
Carpets remain one of the major application areas where PP is used as both backing
and pile component. However, consumption as backing material is higher. Industrial
application include ropes, woven sacks, geotextiles, polygrass, medical and surgical
disposables, tarpaulins etc. it is increasingly being used in woven sacks and soft
luggage. Air-jet textured blended and fancy yarns are used to produce attractive but
cheap and durable upholstery fabrics. Polypropylene non-wovens are increasing being
used as filter fabric for wet filtration in the chemical and pharmaceutical industries.
Polypropylene blankets are also in use along with acrylic ones.
As for the apparel sector, textured polypropylene is finding its way into the hosiery
industry, e.g. in undergarments, swim suits, sportswear, socks, etc. fashioned outwear
is still not its forte, it enjoys a good proportion of the market for activewear products
because of its excellent wicking qualities, transmitting moisture to the outer surface and
reducing the cold, clammy feeling next to the skin. However, blended yarns with acrylic
are now being used to produce hand/machine knitting yarns to give ‘melange’ effects.

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CONCLUSIONS AND RECOMMENDATIONS
7.1. CONCLUSIONS
Work conducted in this study, following conclusions can be made.
 The polypropylene fibres (PPF) reduce early age shrinkage and moisture loss.
 The polypropylene fibres (PPF) has little or insignificant effect on the
compressive strength.
 The polypropylene fibres (PPF) increases the deformation capacity of material
and thus improves the material ductility.
 The polypropylene fibers are relatively care free, stains can easily be wiped off
with damp cloth.
 The fibre is heat sensitive at 250o
F, so it can be laundered at moderate
temperature.
7.2. RECOMMENDATIONS
 The use of Polypropylene fibres (PPF) should be encouraged in various
applications in textiles.
 The PPF should be used in textile to obtain low cost materials
 The effect of PPF on the long term shrinkage and time dependent mechanical
properties should also be studied.

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REFERENCES
History of polyolefins By F.B. Seymour, Tai Cheng
Introduction to polypropylene: Properties, Catalysts Processes By Dennis B. Malpass,
Elliot Band
The chemistry of Textile Fibers By Robert R Mather and Roger H Wardman
Handbook of Fiber Chemistry, Second Edition, Revised and Expanded edited by
Menachem Lewin ,Eli M. Pearce
Manufacture Fiber Technology by VB Gupta and VK Kothari
Handbook of Textile Fibers: Man-Made Fibers by J Gordon Cook