Textile fibres & Their Properties

Textile fibre
• Defenition
A Very fine hair portion of tissues of a plant
small in diameter in relation to their length.

Textile fibre is a hair like substance which can be

converted into yarn and made into fabric with
existing machines. Their length is several
hundred times longer than its diameter
 The requirements of textile fibre
• The minimum possible length should be least
5 mm
• Flexibility
• Cohesiveness
• Sufficient strength
 BROAD CLASSIFICATION OF
TEXTILE FIBRES
Textile Fibres

Natural Fibres Artificial Fibres

Or Manmade

Vegetable Animal Mineral

Origin Origin Origin

Organic Base Inorganic Base

Manmade Fibres Manmade Fibres

Natural Polymer-Base Synthetic Polymer-Base

Regenerated Fibres Manmade Fibres
 NATURAL FIBRES

Vegetable Origin Cellulosic-Base Fibres

Hair Fibre Bast Fibre Leaf Fibre Fruit Fibre

(Cotton) (Jute) (Sisal) (Coir)
(Kapok) (Flax) (Banana fibre-Abaca)
(Hemp) (Pine apple fibre)
(Sunn) (Cantala)
(Kenaf) (Latona)
(Urena) (Caroa)
(Nettle) etc. (Pitafloja)
(Palma) etc.
• This vegitable fibres are classified into two

1.Ligno cellulose fibre-Harsh and stiff

ex-coir,jute,linen,Leaf fibres

2.Non-ligno cellulose
Ex-Cotton, Kapok
 ANIMAL FIBRES

Animal Fibres

Keratin Type of Non-Keratin Type

Protein Staple Fibres Protein Filament Fibres
 MAN-MADE FIBRES
Regenerated Fibres
Natural Polymer Base Fibres

Cellulose Base Protein Base Miscellaneous

(Vicra-Zein of corn (Alginate,
Aedil-peanut Fibre Rubber etc.)
Casein-milk Fibre)

Regenerated Cellulose Cellulose Ester

(Viscose Rayon, (Acetate Rayon,
Cuprammonium Rayon, Triacetate Rayon)
Polynosic HWM Fibres)
 Syntheic Fibres

Condensation Addition Substituted

Polymer Polymer Polymer

Polyamide Polyester Polyolefins Polystyrene

(Terylene, (Polyethylene,
Terene, Polypropylene)
Dacron)

Aliphatic Aromatic
Nomex
Methods Of Spinning Manmade fibres

1. WET SPINNING
2. DRY SPINNING
3. MELT SPINNING
Forms Of fibres
1.Staple fibres
 Staple fibres
• Short fibres
Length ranges from 2 mm to 40mm &
upto 70 mm
Most of the natural fibres are staple fibres
except silk
Synthetic fibres are converted into staple
according to applications
Filament
 Filaments
• Filaments are contious lengths
silk is the natural filement
All synthetic fibres are filements
properties of filements
• More uniform
• High strength
• Easy to handle
• Simple manufacturing
• More lustures
 Raw Material

• Accounts for 80% to 90% of the yarn quality

• 50% to 70% of the yarn cost

• Evaluation of the raw material is therefore

important

• Major raw materials are cotton, polyester &

viscose
King of fibres: Cotton
Cotton
 Varieties of cotton

• Sea Island Cotton

• Egyptian Cotton
• Pima Cotton
• American Upland Long Staple
• American Upland Short Staple
• Asia Short Staple
 Facts about cotton
• A major raw material consumed 50% all over
the world in domestic market

• Having high difference within and between

varieties
• Hygroscopic fibre
• Good absorbency
 Important properties of cotton
• Length
• Uniformity
• Strength
• Elongation
• Fineness
• Maturity
• Moisture
• Colour
Properties of Cotton depends on

• Cotton variety

• Growing areas

• Climatic conditions

• Rain fed or irrigation

• Harvesting

• Picking

• Ginning

• Packing and baling

 QUALITY OF COTTON

• Quality mainly depends on the time of

harvesting early flowering gives good quality
and late flowering gives poor quality
 Testing atmostphere
Standard atmospheric conditions:

• Relative humidity - 65 ± 2% RH

• Temperature - 20 ± 2ºC

• Conditioning time - 24 hours (cotton)

 Variations in results

• Caused by

• Sampling

• Operator

• Instrument
 Length of cotton
• Decids the count to be spun
• Roller setting
• Price of the cotton
 Short fibres
• Gives bulkiness to yarn. Acts as fillers
Causes of short fibre are
1.Ginning
2.Improper speeds and settings

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Fibre properties for different spinning systems

Rank Ring Rotor Air jet

spinning spinning spinning
1 Length / Strength Fineness
Uniformity
2 Strength Fineness Length/
Uniformity
3 Fineness Length/ Strength
Uniformity
4 - Cleanliness Cleanliness

5 - - Friction
 2.5% Span Length

• The distance 2.5% of the fibres extend from the clamp where they
are caught at random along their length.

• This length is numerically nearer to staple length

 50% Span Length

• The distance 50% of the fibres extend from the clamps where they are caught
at random along their length
 Uniformity Ratio

50% Span length

Uniformity Ratio = 2.5% Span length X 100

46 – 50% : Good, 45% : Average, 43% : Poor

Classification of Cottons based on
Span Length

Class 2.5% Span Length (mm)

Extra long staple 33.0 & above
Long staple 29.5 to 32.5
Medium staple 25.0 to 29.0
Short staple A 20.5 to 24.5
Short staple B 20.0 & below
 Fibre Length

• Fibre length variability will cause problems at

every stage of processing such as blow room,
carding, drafting, etc.

• Span length parameters are based only on partial

length of the fibres
 Fibre Strength

• Very weak cottons will rupture during processing

in blow room and carding

• Cottons with bundle strength of 15g/tex and lower

are generally sources of trouble
 fibre fineness
• One of the three most important charectristics

• It decides no of fibres in cross section

• 15000/micxct

• Fineness range 2.9-6 micrograms/inch

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 Classification of fineness
• Coarser fibres
• Finer fibres
• Micro denier
Limits for minimum number of fibres in yarn
cross section

COTTON:
•RING – 75
•ROTOR – 100
SYNTHETIC:
•RING – 50
•ROTOR - 100
 Range of count
• We cannot change the machine setup from
coarser to finer
• Many things like grid bars, beaters, card
wires, nose bar, trumpet and cradle
 FQI
• fibre Quality Index

F Q I=LUSM\F

F Q I=LS\F
To spin a quality yarn the FQI
should be high

38
 Fibre yarn relations
CSP =
280 √ FQI + 700 - 13 C - for Carded counts
W
C S P = ( 280 √ FQI + 700 - 13 C ) ( 1 + -----)
100
- for Combed counts

C - Yarn Count Spun

W - Percentage waste extracted during Combing

 RKm value
• Kilometers of yarn for break in g/tex

Single yarn strength (g) Lea CSP

Tex = 150
 Spinning consistency Index
SCI=-414.67+2.9Fs+49.17UHML+4.74 UI-9.32
Ff+0.65RD+0.36 (+b)

If the SCI is high then the yarn quality will be

good
 Quality Index
• Quality means degree of excelence
• Quality also means ability to meet the needs
• Selection of cotton for a particular need
mostly by experience than technology
 Selection of Cottons for Mixing

• It would be difficult to get a single cotton of desired

quality at different times

• When a single cotton does not satisfy the

requirements

• Important factors - fibre length & its distribution

and fibre fineness
COTTON MIXING — FACTORS
TO BE CONSIDERED

PROPERTY DIFFERENCE

2.5 Span length 5 mm

Micronaire
1.2
Value

Trash % 3.0 %
Contribution of fibre properties to yarn CSP

% Increase in Change in Yarn CSP by

50% Span length +0.5%

Fibre bundle strength +0.5%

Micronaire -0.5%

Maturity Coefficient +0.5%

 Moisture
• Cotton is hygroscopic nature
• Strength depends on RH%
• High moisture makes difficulty in opening
• Low moisture leads to fibre breakages , fly
libaration

46
 Trash
 Non lint content present in fibre

 It influences
Yarn realisation
Appearance

Importance
1.No of beating points
2.beats\inch
3.Dwell time
4.Suction speed
5.setting

47
 Fibre Maturity
• Growth of fibre(Primary wall)

• Measurement of Maturity by caustic soda

swelling

• Maturity lies between 50-80%

48
• Maturity co-eff = Matured+0.6xH.M+0.4 IM
100
• 0.8 and above good
• 0.7 medium
• 0.6 poor
• If Presence of Immature is more

1.Strength is affected
2.Neppiness
3.High short fibre
4.Process difficulties in card

50
 Colour Grade
• Colour is the visual appearance of cotton ,
which ranges from brown yellow to white.

• The colour grading is done by comparing the

cotton with hunters scale.
 Causes for Neps

Raw Material Processed neps

•Fibre fineness •Speeds & settings

•Immature fibres •Card clothing

•Honey dew •Fly liberation

•Dead seeds •Cone winding

•Cleanliness
 Honey dew and wax
• Honey dew due to insect secretion. The allowable
limit is
0.4-0.8%
• Wax is the natural luricant present on the surface
of cotton
Limit should be <0.5%

If these exceeds the limit , it causes

1.Roller lapping
2.Wax deposition on coats & apron
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 Properties for Manmade fibres
• Length
• Strength elongation
• Fineness
• Crimp
• Spin finish
• Delusturing agent

55
 Classification
Regenerated fibres
• Generally termed as Rayons
• Viscose rayon, cupromonium rayon, acetate,
loyocel , Tencel, Modal, Bamboo viscose

Synthetic fibres
Polyester,Nylon,Polyproplene
 About viscose
• The main raw material is Wood pulp and cotton
linters
• The purest form of cellulose called regenerated
fibres
• Obtained through wet spinning
• They feel like cotton but cheep
• Poor wet strength
• Blended with polyester for comfort and lusture
 About synthetic fibres
• They are obtained by synthesis of petrochem
• Mostly hydrophobic in nature
• Mostly used in industrial applications and
functional textiles
• Alternative to wool (acrylic)
• Non bio degradable
• Static charge generation is important problem
during spinning
 crimp
• Man made fibres are cylinder like structure
• They have very smooth surface
• No fibre friction
• fibre separation is difficult
• Important of fibre movement in carding and
drawing
• For psf 4.5 arcs\inch
• For pan 3-5 arcs/inch

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 Insufficient crimp
• Cylinder loading
• Sagging web
• Web rupture
• Roller lapping
High crimp
• Higher neps
• Higher incidence of faults
• Excess neps
• undrafted

60
 Spin finish
• To reduce static charge
• To import lubrication
• Higher leads to roller lapping

61
 Blending
• Blending is mixing of two different fibre
components
• Blending between
• 1.natural fibre with a manmade fibre
• 2.between two synthetic fibres

62
 Purpose of blending
• To use the advantages of both materials
1.To improve inferior material
2.Improved comfort
3.Increased durability
4.Improved asthetics

63
 RELATIVE HUMIDITY & TEMPERATURE FOR
DIFFERENT DEPARTMENTS* (COTTON SPINNING)

TEMPERATURE
DEPARTMENT R.H. %
O C O F
MIXING 60 – 65 27 – 35 80 - 95

BLOW ROOM
CARDING
50 - 55 27 – 35 80 – 95
PREPARATORY

RING SPINNING 50 – 60 27 – 35 80 – 95

WINDING 60 - 65 27 - 32 80 - 90

* About 5% higher (than cotton spinning) RH%

has to be maintained while spinning blended yarns