Assignment on Polyester

5/21/2018 Assignment on Polyester

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1.Polyester--------------------

2.DifferentTypes Of Polyester--------------------------------

3.History of Polyester--------------------

4.Chemical Structure-----------------------5.

Functional Group---------------------

6.

Fibre manufacturing process--------------

6.1.Crimp properties

6.2.Spin finish

6.3.Dry heat shrinkage

6.4.L and B colour

6.5.Dye take up

6.6.Fused fibres

6.7.Lustre

7.

The manufacture of polyester fibre consists of 4 stps7.1..Polymerisation

7.2.Melt spinning

7.3.Drawings

7.4.Cutting

8.

Problems which occur during manufacture of polyester staple fibre--------

9.

Problems faced in polymerisation-----------------------------------------

10.

Polyester fiber characteristics---------------------------

11.

Fibre specification-------------------------------------------

11.1.Denier

11.2.Cut length:12.

End Uses of Polyester----------------------------------------

13.

Use of polyester in garments--------------------------------------13.1.Hydrophobic nature

13.2.Creating insulation

13.3.Wrinkle resistant

14.Industrial uses of polyester------------------------------------

14.1.PET

14.2.Mylar

14.3.Miscellaneous

15.Properties Of Polyester------------------------------

15.1.Physical Properties

15.2.chemical Properties

15.3.Polyester Fiber Properties -Cut Length

15.4.Polyester Fiber Properties - Tensile Properties

15.5.Polyester Properties - Spin Finish


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16.Polyester care tips -------------------------------------------------

17.Care of polyester garment:--------------------------------------


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18. Polyester--------------------

19. DifferentTypes Of Polyester--------------------------------

20.

History of Polyester--------------------21. Chemical Structure-----------------------22.

Functional Group---------------------

23.Fibre manufacturing process--------------

6.1.Crimp properties

6.2.Spin finish

6.3.Dry heat shrinkage

6.4.L and B colour

6.5.Dye take up

6.6.Fused fibres

6.7.Lustre

24.

The manufacture of polyester fibre consists of 4 stps

7.1..Polymerisation

7.2.Melt spinning

7.3.Drawings

7.4.Cutting

25.

Problems which occur during manufacture of polyester staple fibre--------

26.

Problems faced in polymerisation-----------------------------------------

27.

Polyester fiber characteristics---------------------------

28.

Fibre specification-------------------------------------------

11.1.Denier

11.2.Cut length:

29.End Uses of Polyester----------------------------------------

30.

Use of polyester in garments--------------------------------------13.1.Hydrophobic nature

13.2.Creating insulation

13.3.Wrinkle resistant

31.Industrial uses of polyester------------------------------------

14.1.PET

14.2.Mylar14.3.Miscellaneous

32.Properties Of Polyester------------------------------

15.1.Physical Properties

15.2.chemical Properties

15.3.Polyester Fiber Properties -Cut Length


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15.4.Polyester Fiber Properties - Tensile Properties

15.5.Polyester Properties - Spin Finish

33.Polyester care tips -------------------------------------------------

34.Care of polyester garment:--------------------------------------

1.Polyesteris a term often defined as long-chain polymers chemically composed of at least85%by weight of an esterand a dihydric alcoholand aterephthalic acid. In other words, it

means the linking of several esters within the fibers. Reaction of alcohol with carboxylic acid

results in the formation of esters.

Polyester also refers to the various polymers in which the backbones are formed by the

esterificationcondensation of poly functional alcohols and acids.

2.Polyester can also be classified as saturated and unsaturated polyesters.

Saturated polyesters refer to that family of polyesters in which the polyester backbones are

saturated. They are thus not as reactive as unsaturated polyesters. They consist of low molecularweight liquids used asplasticizers and as reactants in forming urethane polymers, and linear,

high molecular weight thermoplasticssuch aspolyethylene terephthalate (Dacron and Mylar).

Usual reactants for the saturated polyesters are a glycol and an acid or anhydride.

Unsaturated polyesters refer to that family of polyesters in which the backbone consists of alkyl

thermosetting resins characterized by vinyl unsaturation. They are mostly used in reinforcedplastics. These are the most widely used and economical family of resins.

3.Characteristics of polyester

Polyester fabrics and fibers are extremely strong.

Polyester is very durable: resistant to most chemicals, stretching and shrinking, wrinkle

resistant, mildew and abrasion resistant.

Polyester is hydrophobic in nature and quick drying. It can be used for insulation bymanufacturing hollow fibers.

Polyester retains its shape and hence is good for making outdoor clothing for harshclimates.

It is easily washed and dried.

4.Uses of Polyester


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The most popular and one of the earliest uses of polyester was to make polyester suitsall the

rage in the 70s. Polyester clothes were very popular. Due to its strength and tenacity polyester

was also used to make ropes in industries. PET bottlesare today one of the most popular uses ofpolyester.

5.Polyester care tips

Taking care of polyester clothing is really easy and very time efficient.

Polyester clothing can be machine washed and dried.Adding a fabric softenergenerally

helps. Dry the fabric at low temperatures to get maximum usage from the clothing.

Though polyester does not require much ironing, if you must then iron warm.

Polyester can be dry-cleaned with no hassles.

Having learned a little something about polyester and how popular it has become, one could

never imagine the history of polyester to be quite so illustrious. The manufacturing process also

deserves a more detailed description. The revival and success of polyester is without doubtsomething that is here to stay.

6.History of Polyester

Scrunch it, pull it, wash itwithout any wear and wrinkles. Thats what polyester became

famous for. Polyester was the fabric of choice in a changing economy of speed, efficiency and

convenience. If thefood industry produced fries and coke, the textile industry supplemented itwith Polyesterquick, cheap and easy.

Carothers Work

It was W.H.Carothers who discovered that alcohols and carboxyl acids could be successfully

mixed to create fibers. Carothers was working for duPontat the time and unfortunately when hediscovered Nylon, polyester took a back seat.

PET & Terylene

Carothers incomplete research had not advanced to investigating the polyester formed from

mixing ethylene glycol and terephthalic acid. It was British scientistsWhinfield and Dickson

who patented PET or PETE in 1941. Polyethylene terephthalate forms the basis for syntheticfibers likeDacron, Terylene and polyester.

Later that year, the first polyester fiberTerylenewas created by Whinfield and Dicksonalong with Birtwhistle and Ritchiethey. Terylene was first manufactured by Imperial Chemical

Industries or ICI.


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DuPonts Role

It was in 1946 that duPont bought all legal rights from ICI. In 1950, the Dealware property of

duPont manufactured another polyester fiber, which they named Dacron. Mylar was introducedin 1952. Polyester was first introduced to the American public in 1951 as the magical fabric

that needed no ironing!PET and PEN are duPont trademarksthat have turned the use andconsumption of Polyester around.

7.Polyester Becomes Popular

Subsequent to the development of Terylene and Dacron, Kodel was developed by Eastman

Chemical Products, Inc in 1958.

The polyester market underwent rapid expansion and textile mills emerged everywhere. Many of

the mills were located at small gas stations and produced cheap polyester apparel. Theinexpensive and durable fiber became very popular and the industry expanded rapidly till the

1970s. Unfortunately, the infamous double-knit polyester image hit the industry and polyester

soon came to be known as the uncomfortable fabric.

The Phoenix Rises

Today, polyester is largely regarded as a cheap fabric that is rather uncomfortable for sensitive

human skin to wear.

However, the emergence of luxury fibers like polyester microfiber and various polyester blendsthe industry is experiencing resurgence. The Tennessee Eastman Company and the Man-MadeFiber Producers Associations (MMFPA)Polyester Fashion Council played a significant role

in the revival of polyester. The Tennessee Eastman Company started a YES campaign forpolYESter and popularized it via radio and television. The idea was to focus on the wash and go

properties of polyester rather than sell it as a cheap fabric.

Hoechst Fibers Industries also played a part. They conducted various studies from 1981 to 1983

and found that 89% of people could not distinguish between polyester and other natural fibers

like cotton, wool and silk. Also, it was found that people were more interested in the appearanceof the apparel than the fabric it was made of.

Today, the biggest contributor to the appeal of polyester is the discovery of microfibers.Microfibers give polyester the feel of silk and are rapidly becoming the choice of fabric. With an

expensive tag to match, the cheap image of polyester seems to be on its way out. Heres to

heralding a new era in the history of polyester!


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8.Manufacturing Polyester

The process of manufacturing polyester is fascinating. It is an artificial man-made fiber.Polyesters are generally manufactured from petroleum from which the constituent acids andalcohols are derived.

There are three steps in the synthesizing of polyester.

1.

Condensation Polymerization: When acid and alcohol are reacted in a vacuum at high

temperatures it results in condensation polymerization. Once the polymerization has occurred

the material is extruded onto a casting trough in the form of a ribbon. Once cool, the ribbon

hardens and is cut into chips.

2.

Melt-spun Fiber: The chips are dried completely. Hopper reservoirs are then used to melt thechips. A unique feature of polyester is that it is melt-spun fiber. The chips are heated, extruded

through spinnerets and cools upon hitting the air. It is then loosely wound around cylinders.

3.

Drawing: The fibers consequently formed are hot stretched to about five times their original

length. This helps to reduce the fiber width. This fiber is now ready and would into cones as

filaments. It can also be crimped and cut into staple lengths as per requirements.

9.Different Types Of Polyester

There are several processes that can be carried out on the base polyester fiber. These processesadd dimension to the polyester fiber as required for various end uses.

Polyester is a bright fiber by nature. However, it can be made dull or semi-dull by adding a

delusterant. By changing the shape of the spinneret also, the hand and the strength of the fiber

can be changed. Most spinnerets are circular. However, square, oval and bean-shaped fibers are

also produced sometimes. Hollow fibers can also be created.

Polyester fiber is generally drawn to about five times its original length. However, drawing it outfurther makes it thinner. This is how the latest microfibers are being manufactured. Dyeing can

give desired colors of polyester fiber. Normal polyester fiber is long and smooth. Crimping it can

give the fiber more bulk and texture and increase its insulation capabilities.

10.Using Polyester

Once the polyester fiber is ready it is used to make filament and spun yarns. The yarns can be

blended with other fibers to make various blended fabrics.

Polyester and cotton are a popular combination. Wool and rayon are also blended with polyesterto make fabrics.


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11.Uses of Polyester

Polyester is the choice of fiber and fabric for many industries. It can be applied to a wide varietyof useful purposes.

12.Use of polyester in garments

Polyester is used in the manufacturing of all kinds of clothes and home furnishings like

bedspreads, sheets, pillows, furniture, carpets and even curtains. The disco clothing of the 70s

with all its jazz and flash was made of polyester.

12.1.Hydrophobic nature:High tenacity and good durability makes polyester the choice of

fabric for high stress outdoors use. Polyester is also a strong fiber that is hydrophobic in nature.It is thus ideal for clothing to be used in wet and damp environments. The fabric is also coated

with a water-resistant finish and further intensifies the hydrophobic nature.

Being the most heavily recycled polymer worldwide, it is also used by climbers. Climbing suits,

parkas, sleeping bags and other outdoor gear are using the new insulating polyester fiberfill

products. One can also do winter windsurfing wearing dry suits lined with polyester fleece.

12.2.Creating insulation: By creating hollow fibers it is also possible to build insulation into the

polyester fiber. Air is trapped inside the fiber, which is then warmed by the heat of the body.This keeps the body warm in cold weather. Another method to build insulation is to use crimped

polyester in a fiberfill. The crimp helps keep the warm air in. Polyester is an ideal fabric for this

kind of insulation because it retains its shape. Cotton and wool tend to flatten over a period of

time and loose the warming effect.

12.3.Wrinkle resistant: Polyester is also wrinkle resistant and is used very often in everydayclothing like pants, shirts, tops, skirts and suits. Used either by itself or as a blend, it is also stain

resistant and hence very popular.

13.Industrial uses of polyester

While clothing used to be the most popular use of polyester and which made it a household name

worldwide, there are many other uses polyester is put to.

13.1.PET: The most common use of polyester today is to make the plastic bottles that store ourmuch beloved beverages. Shatterproof and cheap these bottles are an absolute boon to thebeverages industry.

13.2.Mylar: An unusual and little known use of polyester is in the manufacturing of balloons.Not the rubber kind that you use for water balloons but the really pretty decorated ones that are

gifted on special occasions. These are made of Mylar a kind of polyester film manufactured by

DuPont. The balloons are made of a composite of Mylar and aluminum foil.


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13.4.Miscellaneous: Polyester is also used to manufacture high strength ropes, thread, hoses,

sails, floppy disk liners, power belting and much more in industries.

Thus, polyester has many uses for homes and industries as well.

Source:http://www.whatispolyester.com/

15.POLYESTER FIBRE:

16.Fibre manufacturing process:

Today over 70 to 75% of polyester is produced by CP( continuous polymerisation) process

using PTA(purified Terephthalic Acid) and MEG. The old process is called Batch processusing DMT( Dimethy Terephthalate) and MEG( Mono Ethylene Glycol).

Catalysts like 5b3O3 (ANTIMONY TRIOXIDE) are used to start and control the reaction.

TiO2 (Titanium di oxide) is added to make the polyester fibre / filament dull. Spin finishes areadded at melt spinning and draw machine to provide static protection and have cohesion and

certain frictional properties to enable fibre get processed through textile spinning machinerywithout any problem.

PTA which is a white powder is fed by a screw conveyor into hot MEG to dissolve it. Thencatalysts and TiO 2 are added. After that Esterification takes place at high temperature. Then

monomer is formed . Polymerisation is carried out at high temperature (290 to 300 degree
http://www.whatispolyester.com/http://www.whatispolyester.com/http://www.whatispolyester.com/http://www.whatispolyester.com/


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centigrade) and in almost total vacuum. Monomer gets polymerised into the final product, PET

(Poly ethylene Terephthalate).

This is in the form of thickviscous liquid. This liquid is them pumped to melt spinningmachines. These machines may be single sided or double sided and can have 36/48/64 spinning

positions. At each position , the polymer is pumped by a metering pump-which discharges anaccurate quantity of polymer per revolution ( to control the denier of the fibre) through a pack

which has sand or stainless steel particles as filter media and a spinnerette which could be

circular or rectangular and will have a specific number of holes depending on the technology

used and the final denier being produced. Polymer comes out of each hole of the spinnerette andis instantly solidified by the flow of cool dry air. This process is called quenching. The filaments

from each spinnerette are collected together to form a small ribbon, passed over a wheel which

rotates in a bath of spin finish: and this ribbon is then mixed with ribbon coming from otherspinning positions, this combined ribbon is a tow and is coiled in cans. The material is calledundrawn TOW and has no textile properties.

At the next machine ( the draw machine), undrawn tows from severl cans are collected in the

form of a sheet and passed through a trough of hot water to raise the temperature of polymer to

70 degrees C which is the glass transition temperature of this polymer so that the polymer can bedrawn. In the next two zones, the polymer is drawn approximately 4 times and the actual draw or

the pull takes place either in a steam chamber or in a hot water trough. After the drawing is

complete, each filament has the required denier, and has all its sub microscopic chains aligned

parallel to the fibre axis, thereby improving the crystallinity of the fibre structure and imparting

certain strength.

Next step is to set the strength by annealing the filaments by passing them under tension onseveral steam heated cylinders at temperatures 180 to 220 degrees C. Also the filaments may be

shrunk on the first zone of annealer by over feeding and imparting higher strength by stretching

2% or so on the final zone of the annealer. Next the fibre is quenched in a hot water bath, thenpassed through a steam chest to again heat up the tow to 100 degree C so that the crimping

process which takes place in the stuffer box proceeds smoothly and the crimps have a good

stability. Textile spin finish is applied either before crimping by kiss roll technique or after

crimping by a bank of hollow cone sprays mounted on both sides of the tow. The next step is toset the crimps and dry the tow fully which is carried out by laying the tow on a lattice which

passes through a hot air chamber at 85degree C or so.

The two is guided to a cutter and the cut fibres are baled for despatch. The cutter is a reel havingslots at intervals equal to the cut length desired 32 or 38 or 44 or 51mm. Each slot has a sharp

stainless steel or tungsten carbide blade placed in it. The tow is wound on a cutter reel, at one

side of the reel is a presser wheel which presses the tow on to the blades and the tow is cut. The


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cut fibre falls down by gravity and is usually partially opened by several air jets and finally the

fibre is baled. Some, balers have a preweighting arrangement which enables the baler to produce

all bales of a pre determined weight.

The bale is transported to a ware house where it is "matured" for a minimum of 8/10 days before

it is permitted to be despatched to the spinning mill.

17.FIBRE SPECIFICATION:

17.1.DENIER: Usually the actual denier is a little on the finer side i.e for 1.2 D, it will be 1.16

and for 1.4 , it could be 1.35. The tolerance normally is +- 0.05 and C.V% of denier should be 4to 5%. Denier specifies the fineness of fibre and in a way controls the spinning limit. Theory tells

us that in order to form yarn on ring spinning (and also in air jet) there must be minimum of 60

to 62 ifbres in the yarn cross section. Therefor the safe upper spinning limit with different denier

is

DENIER COUNT(Ne)1.0 90

1.2 80

1.4 62

2.0 40

3.0 32

The limit is for 38 mm fibre. The limit rises for a longer fibres.

When spinning on open end system, the minimum no of fibres in the yarn cross section is 110.So all the fibre producers recommend finer denier fibres for OE spining . Here the safe upperspinning limit is

DENIER COUNT(Ne)

1.0 50

1.2 40

1.4 30

2.0 24

3.0 16

However in actual practice , 30s is an upper limit with OE AND 1.2 Denier is being used,

in USA and other countries, even for 10s count in OE.


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Deniers finer than 1.0 are called micro-denier and commercially the finest polyester stple fibre

that can be worked in a mill is 0.7 D.

17.2.CUT LENGTH:Cut lengths available are 32, 38, 44, 51 and 64mm for cotton type

spinning and a blend of 76, 88 and 102 mm - average cut length of 88m for worsted spinning.

The most common cut length is 38 mm.

For blending with other manmade fibres, spinners preferred 51mm to get higher productivity,

because T.M. will be as low as 2.7 to 2.8 as against 3.4 to 3.5 for 38mm fibre. If the fibre legnthis more, the nepping tendency is also more , so a crompromise cutlength is 44 mm. With this cut

length the T.M. will be around 2.9 to 3.0 and yarns with 35 to 40% lower imprfections can be

achieved compared a to similar yarn with 51 mm fibre. In the future spinners will standardise for38 mm fibre when the ringspinning speed reaches 25000 rpm for synthetic yarns.

For OE spinning , 32 mm fibre is preferred as it enables smaller dia rotor(of 38mm) to be usedwhich can be run at 80000 to 100000 rpm.

Air jet system uses 38 mm fibre.

18.TENSILE PROPERTIES: Polyester fibres are available in 4 tenacity levels.

Low pill fibres- usuall in 2.0 / 3.0 D for suiting enduse with tenacities of 3.0 to 3.5

gpd(grams per denier). These fibres are generally used on worsted system and 1.4D forknitting

Medium Tenacity - 4.8 to 5.0 gpd

High tenacity 6.0 to 6.4 gpd range and

Super high tenacity 7.0 gpd and above

Both medium and high tenacity fibres are used for apparel enduse. Currently most fibre

producers offer only high tenacity fibres. Spinners prefer them since their use enables ringframes to run at high speeds, but then the dyeablity of these fibres is 20 to 25% poorer, also have

lower yield on wet processing, have tendency to form pills and generally give harsher feel.

The super high tenacity fibres are used essentially for spinning 100% polyester sewing threads

and other industrial yarns. The higher tenacities are obtained by using higher draw ratios and

higher annealer temperatures upto 225 to 230 degree C and a slight additional pull of 2% or so atthe last zone in annealing.

Elongation is inversely proportional to tenacity e.g

TENACITYELONGATION AT

BREAK

T10

VALUES

LOW PILL 3.0 - 3.5 45 - 55% 1.0 - 1.5

MEDIUM 4.8 - 5.0 25 - 30% 3.5 - 4.0

HIGH 6.0 - 6.4 16 - 20% 5.2 - 5.5


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SUPER

HIGH7.0 plus 12 - 14% 6.0 plus

All the above values of single fibre. Testing polyester fiber on Stelometer @ 3mm guage is notrecommended.

The T10 or tenacity @ 10% elongation is important in blend spinning and is directly related toblend yarn strength. While spinning 100% polyester yarns it has no significance. Tenacity at

break is the deciding factor.

19.Polyester Fibre manufacturing process - 2

19.1.CRIMP PROPERTIES: Crimps are introduced to give cohesion to the fibre assembly and apart from

crimps/cm. Crimp stability is more important criterion and this value should be above 80% to provide

trouble free working. A simple check of crimp stability is crimps/inch in finisher drawing sliver. This value

should be around 10 to 11, if lower, the fibre will give high fly leading to lappings and higher breaks at

winding. Spin finish also gives cohesion, but cohesion due to crimp is far superior to the one obtained by

finish. To give a concrete example, one fibre producer was having a serious problem of fly with mill dyed

trilobal fibre. Trilobal fibre is difficult to crimp as such, so it was with great difficulty that the plant couldput in crimps per inch of 10 to 11. Dyeing at 130 degrees C in HTHP dying machine reduced the cpi to 6

to 8. Mills oversprayed upto 0.8% did not help. Card loading took place yet fly was uncontrolled,

ultimately the fibre producer added a steam chest to take the two temperature to 100degrees plus

before crimping and then could put in normal cpcm and good crimp stability. Then the dyed fibre ran

well with normal 0.15 to 0.18 % added spin finish.

19.2.SPIN FINISH: Several types of spin finishes are available. There are only few spin finish

manufacturers - Takemoto, Matsumoto, Kao from Japan, Henkel, Schill &Scheilacher, Zimmer & Schwarz

and Hoechst from Germany and George A.Goulston from USA. It is only by a mill trial that the

effectiveness of a spin finish can be established.

A spin finish is supposed to give high fibre to fibre friction of 0.4 to 0.45, so as to control fibre movement

particularly at selvedges , low fibre-metal friction of 0.2 to 0.15 to enable lower tensions in ring spinning


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and provide adequate static protection at whatever speed the textile machine are running and provide

enough cohesion to control fly and lapping tendencies and lubrication to enable smoother drafting.

Spin finish as used normally consists of 2 components - one that gives lubrication / cohesion and other

that gives static protection. Each of these components have upto 18 different components to give

desired properties plus anti fungus, antibacterial anti foaming and stabilisers.

Most fibre producers offer 2 levels of spin finishes. Lower level finish for cotton blends and 100%

polyester processing and the higher level finish for viscose blend. The reason being that viscose has a

tendecy to rob polyester of its finish. However in most of the mills even lower spin finish works better

for low production levels and if the production level is high, high level spin finish is required if it is mixed

with viscose.

For OE spinning where rotor speeds are around 55000 to 60000 rpm standard spin finish is ok, but if a

mill has new OE spinning machines having rotors running @80000 rpm, then a totally different spin

finish which has a significantly lower fibre - fibre and fibre - metal friction gave very good results. The

need to clean rotors was extended from 8 hours to 24 hours and breaks dropped to 1/3rd.

In conclusion it must be stated that though the amount of spin finish on the fibre is only in the range

0.105 to 0.160, it decides the fate of the fibre as the runnability of the fibre is controlled by spin finish,so it is the most important component of the fibre.

Effectiveness of spin finish is not easy to measure in a fibre plant. Dupont uses an instrument to

measure static behaviour and measures Log R which gives a good idea of static cover. Also, there is s

Japanese instrument Honest Staticmeter, where a bundle of well conditioned fibre is rotated at high

speed in a static field of 10000 volts. The instrument measures the charge picked up by the fibre sample,

when the charge reaches its maximum value, same is recorded and machine switched off. Then the time

required for the charge to leak to half of its maximum value is noted. In general with this instrument ,

for fibre to work well, maximum charge should be around 2000 volts and half life decay time less than

40 sec. If the maximum charge of 5000 and half life decay time of 3 min is used , it would be difficult to

card the fibre , especially on a high production card.


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19.3.DRY HEAT SHRINKAGE: Normally measured at 180 degree C for 30 min. Values range from 5 to 8 %.

With DHS around 5%, finished fabric realisation will be around 97% of grey fabric fed and with DHS

around 8% this value goes down to 95%. Therefore it makes commercial sense to hold DHS around 5%.

19.4.L and B colour: L colour for most fibres record values between 88 to 92. "b" colour is a measure of

yellowness/blueness. b colour for semidull fibre fluctuates between 1 to 2.8 with different fibre

producers. Lower the value, less is the chemicals degradation of the polymer. Optically brightened fibres

give b colour values around 3 to 3.5. This with 180 ppm of optical brightner.

19.5.DYE TAKE UP: Each fibre producer has limits of 100 +- 3 to 100+-8. Even with 100+-3 dye limits

streaks do occur in knitted fabrics. The only remedy is to blend bales from different days in a despatch

and insist on spinning mills taking bales from more than one truck load.

19.6.FUSED FIBRES: The right way to measure is to card 10 kgs of fibre. Collect all the flat strips(95% of

fused fibres get collected in flat strips). Spread it out on a dark plush, pick up fused and undrawn fibres

and weigh them. The upper acceptable limit is 30mgm /10kgs. The ideal limit should be around

15mgm/10kgs. DUpont calls fused/undrawn fibres as DDD or Deep Dyeing Defect.

19.7.LUSTRE: Polyester fibres are available in

bright : 0.05 to 0.10 % TiO2

Semil dull : 0.2 to 0.3 % TiO2

dull : 0.5 % TiO2

extra dull : 0.7% TiO2 and

in optically brightened with normally 180 ppm of OB, OB is available in reddish , greenish and bluish

shades. Semi dull is the most popular lustre followed by OB (100 % in USA) and bright.


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20.PHYSICAL AND CHEMICAL PROPERTIES OF POLYESTER FIBRE:

DENIER: 0.5 - 15

TENACITY : dry 3.5 - 7.0 : wet 3.5 - 7.0

%ELONGATION at break : dry 15 - 45 : wet 15 45

%MOISTURE REGAIN: 0.4

SHRINKAGE IN BOILING WATER: 0 - 3

CRIMPS PER INCH: 12 -14

%DRY HEAT SHRINKAGE: 5 - 8 (at 180 C for 20 min)

SPECIFI GRAVITY: 1.36 - 1.41

% ELASTIC RECOVERY; @2% =98 : @5% = 65

GLASS TRANSITION TEMP: 80 degree C

Softening temp : 230 - 240 degree C

Melting point : 260 - 270 degree C

Effect of Sunlight : turns yellow, retains 70 - 80 % tenacity at long exposure

RESISTANCE TO WEATHERING: good

ROT RESISTENCE: high

ALKALI RESISTENCE: damaged by CON alkali

ACID RESISTENCE: excellent

ORGANIC CHEMICAL RESISTENCE: good

21.PROBLEMS WHICH OCCUR DURING MANUFACTURE OF POLYESTER STAPLE FIBRE:


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22.The manufacture of polyester fibre consists of 4 stps:

22.1.Polymerisation:Using PTA/DMT and MEG on either batch or continuous polymerisation (cp_ -

forming final polymer

22.2. Melt spinning :Here molten polymer is forced thorough spinnerette holes to form undrawn

filaments, to which spin finish is applied and coiled in can

22.3.Drawings: in which several million undrawn filaments are drawn or pulled approximately 4 times

in 2 steps, annealed, quenched, crimped and crimp set and final textile spin finish applied and

22.4.Cutting: in which the drawn crimped tow is cut to a desired 32/38/44/51 mm length and then

baled to be transported to a blend spinning mill.

23.PROBLEMS FACED IN POLYMERISATION:

properties of Polymer: The polymer formed is tested mainly for intrinsic viscosity (i.v), DEG content, %

oligeomers and L and b colours. Intrinsic viscosity is an indirect measure of degree of polymerisation and

this value is around 0.63 for polymer meant for apparel fibres. DEG or Di Ethylene Glycol gets formed

during polymerisation and varies from 1.2 to 1.8%. Oligomers are polymers of lower molecular weight

and vary in quantity from 1.2 to 1.8 %. L and b are measures of colour. L colour signifies whiteness as avalue of 100 for L is a perfect value. Most fibres have L colour values around 88 to 92. b colour denotes

yellowness/blueness of polymer. the positive sign for b colour indicates yellowness whilst negative sign

shows blueness, only polymer which contain optical brightener has b of 3 - 3.5 whilst all semil dull

polymers show b values of 1.0 to 2.4. Higher values indicate more yellowness, which indirectly shows

chemical degradation of the polymer.

Running a CP @ lower / higher throughput: Every CP is designed for a certain throughput per day. Like

say 180 tons/day or 240 tons/day. Sometimes due to commercial constraints like high buildup of fibre

stocks etc. , the CP may have to be operated at lower capacityies. In that case the polymer that is

produced has a higher "b" colour and a lower DEG content.


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Higher "b" colour of say 1.5 against normal value of 1.0 will show fibre to be yellowish and hasa little more chemical degradation; which gives higher fluorescence under UV light. Most

spinning mills have a practice of checking every cone wound under UV lamp to find outwhether there has been any mixup.

However if a mill is consistently receiving fibre with a "b"colour of say 1.0 and then if onedespatch comes of "b"colour of say 1.5 then in winding, ring bobbins of both "b" colours will be

received, and when cones are wound and checked under UV lamp, then higher "b" colour

material will give higher fluorescence compared to that of lower "b" colour materials, and willcause rings under UV lamp. Fortunately a minor difference in "b" colour of 0.4 to 0.5 does not

give variation in dyeability.

http://textiletechinfo.com/spinning/POLYESTERmanu.htm

24.Polyester

Polyesteris the general name for any group of widely used synthetic products. Polyestersare strong, tough materials that are manufactured in a variety of colours, shapes and sizes.

25.History of the use of polyester:

The first commercial production of polyester was by the du Pont de Nemours Company. It isthe most used fibre in the United States.

26.Production of polyester:

Polyesters are made from chemical substances foundmainly in petroluem. Polyesters are manufactured inthree basic forms - fibers, filmsand plastics.

Polyester fibers are used to make fabrics. Poly(ethylene terephthalate, or simply PET) is the most

common polyester used forfiber purposes. This is the

polymer used for making soft

drink bottles. Recycling PET byre-melting it and extruding itas fiber saves much raw materials as well as energy.
http://textiletechinfo.com/spinning/POLYESTERmanu.htmhttp://textiletechinfo.com/spinning/POLYESTERmanu.htmhttp://textiletechinfo.com/spinning/POLYESTERmanu.htm


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PET is made by ethylene glycol with either terephthalic acid or its methyl ester in the

presence of an antimony catalyst. In order to achieve high molecular weights needed toform useful fibers, the reaction has to be carried out at high temperature and in a vacuum.

27.Care of your polyester garment:

1) Machine-wash your fabric in cold water.2) Wash with light colours.

3) Use a gentle cycle while washing.

4) Tumble dry with the setting low.5) Do not bleach.6) If needed, iron with a cool iron.

28.Properties of the polyester:

1)It is resists wrinkling.2)It is easy to launder.3)It dries quickly.4)It is resistant to stretching and shrinking.

29.Uses:

Polyester is used to make most forms of clothing like shirts, running shorts, track pants,windbreakers, and lingerie. It can also be made into curtains and draperies.

http://library.thinkquest.org/C004179/polyester.htm


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30.Physical & Chemical Properties of Polyester

\polyester is a very important manmade fibre.Polyester is produced with a long chain synthetic polymerwith ester.Polyester is produced by melt spinning process.Here,I have given physical and chemical

properties of polyester fiber which is important to know.

31.Physical properties of Polyester:

Like cotton or other fiber,polyester fiber consists of some important physical properties.Important

physical properties of polyester are given below.

1.

Tenacity:5-7gm/den2.

Elongation at break:15-30%

3.

Elastic Modulus:90

4.

Elasticity:Good

5.

Moisture Reagain(MR%):0.40%

6.

Specific gravity:1.38

7. Melting Point:250c

8.

Volumetric swelling:None

9.

Ability to protest friction:Excellent

10.

Coor:White

11.

Light reflection ability:Good12.

Lusture:Bright

32.Chemical Properties of polyester:

Various types of chemical properties of polyester fiber are given below:

1.

Acids:Good resistance to acids in cold condition.But polyester degrades by H2SO4 at high

temperature.

2.

Basic:Good resistance to basic in cold condition but strong NaOH dissolves polyester in boiling.3.

Effect of Bleaching:Polyester does not affected by bleaching process.

4.

Protection ability against mildew:Good

5.

Protection ability against insects:Good

6.

Dyes:Polyester could be dye with disperse,azoic color and some pigments.

7.

Solvents of polyester:Following are solvents of polyester:

Chlorinated hydrocarbon


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F3COOH

Phenol (in hot condition)

So,during processing of polyester,we have to consider the physical and chemical properties of polyester.

http://textilefashionstudy.com/polyester-physical-and-chemical-properties-of-

polyester/

33.A manufactured fiber in which the fiber forming substance is any long-chain synthetic polymer

composed of at least 85% by weight of an ester of a substituted aromatic carboxylic acid, including but

not restricted to substituted terephthalic units, p(-R-O-CO- C6H4-CO-O-)x and parasubstituted hydroxy-benzoate units, p(-R-O-CO-C6H4-O-)x.

34.Polyester Fiber Characteristics

Strong

Resistant to stretching and shrinking

Resistant to most chemicals

Quick drying Crisp and resilient when wet or dry

Wrinkle resistant

Mildew resistant

Abrasion resistant

Retains heat-set pleats and crease

Easily washed

35.Polyester Fiber Properties - Cut Length

Cut lengths available are 32, 38, 44, 51 and 64mm for cotton type spinning and a blend of 76, 88 and 102

mm - average cut length of 88m for worsted spinning. The most common cut length is 38 mm.

For blending with other manmade fibres, spinners preferred 51mm to get higher productivity, because

T.M. will be as low as 2.7 to 2.8 as against 3.4 to 3.5 for 38mm fibre. If the fibre legnth is more, the

nepping tendency is also more , so a crompromise cutlength is 44 mm. With this cut length the T.M. will

be around 2.9 to 3.0 and yarns with 35 to 40% lower imprfections can be achieved compared a to similar

yarn with 51 mm fibre. In the future spinners will standardise for 38 mm fibre when the ringspinning

speed reaches 25000 rpm for synthetic yarns.


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For OE spinning , 32 mm fibre is preferred as it enables smaller dia rotor(of 38mm) to be used which can

be run at 80000 to 100000 rpm.

Air jet system uses 38 mm fibre.

36.Polyester Fiber Properties - Tensile Properties

Polyester fibers are available in 4 tenacity levels.

Low pill fibres- usuall in 2.0 / 3.0 D for suiting enduse with tenacities of 3.0 to 3.5 gpd(grams per denier).

These fibres are generally used on worsted system and 1.4D for knitting

Medium Tenacity - 4.8 to 5.0 gpd

High Tenacity - 6.0 to 6.4 gpd range andSuper high tenacity - 7.0 gpd and above

Both medium and high tenacity fibres are used for apparel enduse. Currently most fibre producers offer

only high tenacity fibres. Spinners prefer them since their use enables ring frames to run at high speeds,

but then the dyeablity of these fibres is 20 to 25% poorer, also have lower yield on wet processing, have

tendency to form pills and generally give harsher feel.

The super high tenacity fibres are used essentially for spinning 100% polyester sewing threads and other

industrial yarns. The higher tenacities are obtained by using higher draw ratios and higher annealer

temperatures upto 225 to 230 degree C and a slight additional pull of 2% or so at the last zone inannealing.

Elongation is inversely proportional to tenacity e.g

--------- Tenacity-----Elongation at Break------T10 Values

Low Pill----3.0-3.5--------45-55%--------------------1.0-1.5

Medium----4.8-5.0--------25-30%--------------------3.5-4.0

High--------6.0-6.4--------16-20%--------------------5.2-5.5

Super Hi----7.0 plus-------12-14%--------------------6.0 plus

The T10 or tenacity @ 10% elongation is important in blend spinning and is directly related to blend yarn

strength. While spinning 100% polyester yarns it has no significance. Tenacity at break is the deciding

factor.


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Polyester Fiber Properties - Crimp PropertiesCrimps are introducd to give cohesion to the fibre assembly

and apart from crimps/cm. Crimp stability is more important criterion and this value should be above

80% to provide trouble free working. A simple check of crimp stability is crimps/inch in finisher drawing

sliver. This value should be around 10 to 11, if lower, the fibre will give high fly leading to lappings and

higher breaks at winding. Spin finish also gives cohesion, but cohesion due to crimp is far superior to the

one obtained by finish.To give a concrete example, one fibre producer was having a serious problem of

fly with mill dyed trilobal fibre. Trilobal fibre is difficult to crimp as such, so it was with great difficulty

that the plant could put in crimps per inch of 10 to 11. Dyeing at 130 degrees C in HTHP dying machine

reduced the cpi to 6 to 8. Mills oversprayed upto 0.8% did not help. Card loading took place yet fly was

uncontrolled, ultimately the fibre producer added a steam chest to take the two temperature to

100degrees plus before crimping and then could put in normal cpcm and good crimp stability. Then the

dyed fibre ran well with normal 0.15 to 0.18 % added spin finish.

37.Polyester Properties - Spin Finish

Several types of spin finishes are available. There are only few spin finish manufacturers - Takemoto,

Matsumoto, Kao from Japan, Henkel, Schill &Scheilacher, Zimmer & Schwarz and Hoechst from Germany

and George A.Goulston from USA. It is only by a mill trial that the effectiveness of a spin finish can be

established.

A spin finish is supposed to give high fibre to fibre friction of 0.4 to 0.45, so as to control fibre movement

particularly at selvedges , low fibre-metal friction of 0.2 to 0.15 to enable lower tensions in ring spinning

and provide adequate static protection at whatever speed the textile machine are running and provide

enough cohesion to control fly and lapping tendencies and lubrication to enable smoother drafting.

Spin finish as used normally consists of 2 components - one that gives lubrication / cohesion and other

that gives static protection. Each of these components have upto 18 different components to give

desired properties plus anti fungus, antibacterial anti foaming and stabilisers.

Most fibre producers offer 2 levels of spin finishes. Lower level finish for cotton blends and 100%

polyester processing and the higher level finish for viscose blend. The reason being that viscose has a

tendecy to rob polyester of its finish. However in most of the mills even lower spin finish works better

for low production levels and if the production level is high, high level spin finish is required if it is mixed

with viscose.

For OE spinning where rotor speeds are around 55000 to 60000 rpm standard spin finish is ok, but if a

mill has new OE spinning machines having rotors running @80000 rpm, then a totally different spin

finish which has a significantly lower fibre - fibre and fibre - metal friction gave very good results. The

need to clean rotors was extended from 8 hours to 24 hours and breaks dropped to 1/3rd.

In conclusion it must be stated that though the amount of spin finish on the fibre is only in the range


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0.105 to 0.160, it decides the fate of the fibre as the runnability of the fibre is controlled by spin finish,

so it is the most important component of the fibre

Effectiveness of spin finish is not easy to measure in a fibre plant. Dupont uses an instrument to

measure static behaviour and measures Log R which gives a good idea of static cover. Also, there is s

Japanese instrument Honest Staticmeter, where a bundle of well conditioned fibre is rotated at high

speed in a static field of 10000 volts. The instrument measures the charge picked up by the fibre sample,

when the charge reaches its maximum value, same is recorded and machine switched off. Then the time

required for the charge to leak to half of its maximum value is noted. In general with this instrument ,

for fibre to work well, maximum charge should be around 2000 volts and half life decay time less than

40 sec. If the maximum charge of 5000 and half life decay time of 3 min is used , it would be difficult to

card the fibre , especially on a high production card.

Polyester Properties - Dry Heat ShrinkageNormally measured at 180 degree C for 30 min. Values range

from 5 to 8 %. With DHS around 5%, finished fabric realisation will be around 97% of grey fabric fed and

with DHS around 8% this value goes down to 95%. Therefore it makes commercial sense to hold DHS

around 5%.

L and B colourL colour for most fibres record values between 88 to 92. "b" colour is a measure of

yellowness/blueness. b colour for semidull fibre fluctuates between 1 to 2.8 with different fibre

producers. Lower the value, less is the chemicals degradation of the polymer. Optically brightened fibres

give b colour values around 3 to 3.5. This with 180 ppm of optical brightner.

Dye Take UpEach fibre producer has limits of 100 +- 3 to 100+-8. Even with 100+-3 dye limits streaks do

occur in knitted fabrics. The only remedy is to blend bales from different days in a despatch and insist on

spinning mills taking bales from more than one truck load.

Fused FibersThe right way to measure is to card 10 kgs of fibre. Collect all the flat strips(95% of fused

fibres get collected in flat strips). Spread it out on a dark plush, pick up fused and undrawn fibres and

weigh them. The upper acceptable limit is 30mgm /10kgs. The ideal limit should be around

15mgm/10kgs. DUpont calls fused/undrawn fibres as DDD or Deep Dyeing Defect.

Polyester LustrePolyester fibres are available in

Bright : 0.05 to 0.10 % TiO2

Semil dull : 0.2 to 0.3 % TiO2

Dull : 0.5 % TiO2

Extra dull : 0.7% TiO2 and in optically brightened with normally 180 ppm of OB, OB is available in reddish

, greenish and bluish shades. Semi dull is the most popular lustre followed by OB (100 % in USA) and

bright.

38.Polyester Fiber Uses

Apparel: Every form of clothing

Home Furnishings: Carpets, curtains, draperies, sheets and pillow cases, wall coverings, and

upholstery


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Other Uses: hoses, power belting, ropes and nets, thread, tire cord, auto upholstery, sails,

floppy disk liners, and fiberfill for various products including pillows and furniture

Read more:http://textilelearner.blogspot.com/2011/07/polyester-fiber-

characteristics-of_11.html#ixzz2XTptr911
http://textilelearner.blogspot.com/2011/07/polyester-fiber-characteristics-of_11.html#ixzz2XTptr911http://textilelearner.blogspot.com/2011/07/polyester-fiber-characteristics-of_11.html#ixzz2XTptr911http://textilelearner.blogspot.com/2011/07/polyester-fiber-characteristics-of_11.html#ixzz2XTptr911http://textilelearner.blogspot.com/2011/07/polyester-fiber-characteristics-of_11.html#ixzz2XTptr911http://textilelearner.blogspot.com/2011/07/polyester-fiber-characteristics-of_11.html#ixzz2XTptr911http://textilelearner.blogspot.com/2011/07/polyester-fiber-characteristics-of_11.html#ixzz2XTptr911

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