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Transcript of Fibres
TEXTILES
FIBRES
YARNS
FABRICS
PROCESSING
MANUFACTURE
APPLICATION
PROPERTIES DESIGN
VALUE ADDITION MARKET
TEXTILES
• A Textile is a flexible material comprised of a network (interlacement / Interlooping / Bonded) of natural or artificial FIBERS
• The term ‘Textile' is a Latin word taken from the
word ‘TEXERE' which means ‘to weave'.
• The term Textiles covers Fibres, Yarns and Fabrics.
Organizational Structure of Textile
Industry
Vertical Horizontal
This does not refer to the shape of the factorybut to the ways in which, the various parts of
the structure relate to each other..
Vertical Organization
A company which is structured in such a way that it takes in a basic raw material and performs all of the necessary processing functions to convert it into the finished product is said to be vertical or vertically organized..
Vertical StructureMacMillan Textiles Ltd.
Spin Yarn
Weave/Knit fabric
Wet processing
Making-up
End-product
Fibre
Wholesale/retail
Horizontal Organization
A company that only performs part of the overall manufacturing process, the products of which become raw materials for the next company in the processing sequence..
Horizontal Structure
SpinnersFibre Yarn
Weavers Knitters
Fabric Fabric
Wet Processors
Making-up End-Product Wholesaler/Retailer
Converters
Structure with both Vertical & Horizontal elements
Weavers Yarn
Spin Yarn
Weave
Wet processing
Making-up
End-products
Wholesale/retail
Fibre Knitters
Wet processingConverters
Making-up
End-products
Wholesale/retail
Manufacturing Sequence..
The wet processor could have all the above stages as raw material :
Raw Fibre
Yarn
Fabric
Spin
Weaving or
Knitting
Cut & Sew
Garment
Knit
PRODUCTION METHODS
DRY PROCESSING• Fiber Processing• Dry Spinning• Weaving • Knitting• Crocheting• Felting• Braiding• Knotting• Netting
WET PROCESSING
• Wet Spinning• Preparation Process• Coloration Process• Finishing Process
Fibers
How a Linear Structure Is Formed
?
Fiber is a linear structure
Polymerization• A long continuous
chain formed by one chemical or by the reaction of more chemicals that produces a repetitive chain.
• One unit that repeats in polymer is called a monomer.
Polymerization happens:• As a natural process.(natural)
• With natural material under controlled conditions.(man made)
• With synthetic material /chemicals under controlled conditions.(synthetic)
The history of fibres is as old as human civilization.
Traces of natural fibres have been located to ancient civilizations all over the globe. For many thousand years, the usage of fiber was limited by natural fibres such as flax, cotton, silk, wool and plant fibres for different applications.
Flax is considered to be the oldest and the most used natural fibre since ancient times
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Fiber• A basic and fundamental unit of textiles• A long slender thread like structure of cell• A smallest entity of textiles we wear
• A unit of matter which is capable of being spun into a yarn or made into a fabric by bonding or by interlacing in a variety of methods including weaving, knitting, braiding, felting, twisting, or webbing, and which is the basic structural element of textile products.
• It is a smallest textile component which is microscopic hair like substance that may be man made or natural.
• They have length at least hundred times to that of their diameter or width
• Fibres used for apparel range in length from about 15mm to 150mm.
• Flax ranges up to 500mm and more
• Thickness of these fibres tend to range from about 10µm to 50µm
Staple Fiber
• A basic standard length of fiber is called staple length
• The fibre can be a short staple or a long staple.• It may be natural or continuous fibers may be cut
to a staple length
Filament• A long continuous fibrous structure ranging
in length from a few hundred
meters (silk) to several kilometers
(man made fibres) Thickness of filaments is silmilar to that of fibres
• Mono filament
– A strand containing a long continuous filament
• Multi filament
– A strand containing 2 or more filaments
Properties of Textile FiberFIBRE MORPHOLOGY:
Macro structure of Micro structure of fibre and filament fibre and filament Fibre length Microscopic - Fibre thickness AppearanceLength to breadth ratio Microscopic-Colour longitudinal struc.Translucency Microscopic-Lustre cross sectional struc.
Sub Microscopic struc.
Properties of Textile Fiber
Primary• Fiber length• Tenacity• Cohesiveness• Flexibility
Secondary• Evenness• Porosity• Resiliency• Lustre• Durability• Shape and appearance
PROPERTIES OF FIBRES
Properties of fibers can be classified based on various factors like :-
– Visual / Physical properties– Microscopic properties– Chemical properties– Mechanical properties– Environmental & Biological properties– Thermal properties– Electrical properties
Physical properties of FIBERS
Physical properties are those which can be seen in appearance.
A) COLOURB) SHAPEC) COVERD) HAND
E) LUSTERF) FIBRE
LENGTH
Fiber Length• The average length of fiber is termed as
fiber length.• The length is to make a long continuous
strand with small length staple fibers minimum fiber length is 5mm.
• The fiber should have minimum length to width ratio of 1:100.
COLOUR
• COLOUR:- manufactured fibers are usually white in color where as natural fiber may vary in shades white to brown or tan to black e.g. (color of wool fiber depends on sheep )
SHAPE• SHAPE:- shape of a fiber is determined by its cross sections
.often it can also be included in microscopic properties of fiber. All fibers have length ,cross section ,surface contour and diameter and also some fibers have crimp.
• Length :fibers may be staple or filament• Cross section :it is referred to the appearance of the fiber
when viewed across its diameter.• Surface :surface contour is sometimes referred to as
longitudinal appearance.• Diameter : it is the width of the cross section.• Crimp : the wave or bump of the fiber.
Fiber Fineness
• The fiber fineness is the relative measurement of its size, diameter and linear density.
• It also suggests the uniformity of the fiber.
Uniformity / Evenness
• Uniformity in thickness and length of fiber gives more even and fine yarns resulting in fine quality
Cohesiveness.• The property of an
individual fiber by virtue of which the fibers hold on one another when spun into yarn.
• For e.g, cotton’s convolutions,wools scales help them to hold themselves.
COVER
Cover is the ability to occupy an area it varies from fiber to fiber
(e.g. wool, asbestos , flax, hemp etc)
HAND
• Hand is the way a fiber feels when handled. Fiber shapes vary and includes round, flat and multimodal (e.g. soft, crisp, dry, silky or harsh)
LUSTER Luster is the quality of fiber to reflect the light
from its surface.• Different fibers have different luster properties.• Silk has high luster in natural fibers.• Most of the man made fibers have high degree of luster.• The luster of fibers can be varied by different processes.
CHEMICAL PROPERTIES OF FIBERS CHEMICAL PROPERTIES OF FIBERSChemical properties of fibers can be defined as those properties of fibers which they exhibit when they come in contact with any kind of chemicals.
It is very necessary to understand various chemical properties of different fibers because
1. It relates directly to the care required in daily processing like cleaning, washing and ironing .
2. Also because fibers usually come in contact with chemicals during textile processing like dyeing and printing and various other finishes.
Generally it can be said that synthetic fibers have less chemical reactivity than natural fibers. But different fibers react differently with various kinds of chemicals………..
CHEMICAL PROPERTIES OF FIBERS
• Chemical properties of different fibers depend on the inbuilt properties of fibers.
• Also the effect of a chemical on the fiber will be determined by:
• The type of chemical• The strength of chemical and the strength of fiber• Time of exposure of the fiber to the chemical.
• Chemical reactivity of different fibers basically includes:
• EFFECTS OF ALKALIES• EFFECTS OF ACIDS• EFFECTS OF OXIDISING AGENTS• EFFECTS OF SOLVENTS• ABSORBENCY / POROSITY
1. EFFECT OF ACIDS
The effect of acids on a fiber is determined by the type and strength of the acid. mineral acids even in dilute concentration will damage natural fibers like cotton. however dilute concentrations of acids will not harm protein fibers like wool (even they are used in wool processing .
2. EFFECT OF ALKALIES
Alkalies do not harm natural cellulosic fibers such as cotton which is often treated with NaOH to improve its strength . various soaps and detergents are not recommended for wool as they are alkaline in nature and alkalis are not suitable for protein fibers.
3. EFFECTS OF OXIDISING AGENTS
Oxidizing agents such as chlorine bleach are used to remove colors or stains in fibers. For example many natural fibers are not white enough to give good dye results, so they are treated with bleaches. However chlorine based bleaches are not suitable for protein fibers whereas it can safely be used on nylon and polyester. Cotton requires controlled bleaching.
4. EFFECTS OF SOLVENTS
Chemical solvents are used in dry cleaning. organic solvents are used to remove oily stains and dirt. Acetone is one of the solvents that will damage both acetate and triacetate.
Porosity
• Porosity is volume of air contained within the volume of the fiber.
• This facilitates absorption of moisture, lubricants and dyes.
• Natural fibers have higher porosity than synthesized.
Mechanical properties of fibers
The mechanical properties of fibers are determined in a textile testing laboratory.
These procedures make possible accurate evaluation of the quality of textile products.
» Abrasion Resistance» Dimensional Stability» Elastic Recovery» Pilling » Flexibility» Resiliency or Wrinkle Recovery» Specific Gravity or Density» Tenacity
Abrasion Resistance
Abrasion Resistance is the ability of a fiber to withstand the effects of rubbing or friction. It is a significant factor in the
durability of a fiber. e.gNylon is used extensively in action outerwear, such as ski jackets, because it is very strong and resists abrasion.Excellent abrasion resistance -Nylon, AramidPoor abrasion resistance -Glass, Acetate.
Excellent abrasion resistance
ABRASION RESISTANCE OF DIFFERENT FIBRES
EXCELLENTNYLON
POLYESTER
GOODCOTTON RAYON
FAIRWOOLSILK
RAYON-VISCOSE
POORGLASS
ACETATETRIACETATE
DIMENSIONAL STABILITY:-• It is the ability of a fiber to maintain its original shape,
neither shrinking nor stretching.• Some varieties of Rayon and wool shrink progressively.
PILLING:-Pilling is the formation of small balls of loose fibres on the
surface of a fabric, results from abrasion.The tumbling action of washing and automatic drying may also cause pilling.
Excellent against pilling- Rayon CottonFlax Glass
Poor against pilling - Nylon Polyester
Excellent against pilling
Poor against pilling
nylon
polyester
ELASTIC RECOVERY:-Ability of a fiber to return to its original
length.
Elastomeric fibers like spandex can be stretched 100 percent and still return to its original length.
Fibres with high Elastic Recovery recovers its creep after being compressed.
FLEXIBILITY
The ability of fiber to be plied or twisted without any rupture to the fiber.
• Fibers that bend or fold easily have good flexibility.
• The fiber should be sufficiently pliable so that it can wrap around another fiber when spun. Stiff fibers are hard to spin into yarn and create fabric with limited consumer appeal.
• It contributes greatly to the drape of a fiber.
• All man made cellulosic fibers have good flexibility.
RESILIENCY OR WRINKLE RECOVERY:-
It is the ability of a fiber to return to its original shape after being bent or folded. Fibres with good resiliency like polyester are often used in apparel when retention of appearance is important.
Compressive resiliency or loft is the ability of a fiber to return to its original thickness after it is crushed.
RESILIENCY OF DIFFERENT FIBRES
EXCELLENT
Glass
Nylon
Polyester
GOOD
Wool
Triacetate
Acrylic
FAIR
Silk
POOR
Rayon
Cotton
Flax
Acetate
RESILIENCY OF DIFFERENT FIBRES
Resiliency
• The resistance to compression, flexing or torsion is termed as resiliency. Some fibers have natural tendency to return to their original condition after the applied force is removed.
• This is an important factor considered while
selecting the fibres for carpet.
Tenacity / Fibre Strength• The strength of material, when it is loaded along
its load axis is called tensile strength or tenacity of the fiber .
• In general, strong fibers last longer and provide more service than do weak fibers.
• Tenacity or Fiber strength, is important factor contributing to the wear life of a textile product.• Nylon, Aramid and Glass fibers are noted for their
strength. Acetate and Acrylic are relatively weak, in contrast.
MECHANICAL PROPERTIES OF MAJOR TEXTILE FIBRES
FIBER STRENGTH
ABRASION RESISTANCE
RESILIENCY
PILLNG RESISTANCE
SPECIFIC GRAVITY DENIER
COTTON GOOD 3.0-5.0 GOOD POOR EXCELLENT 1.54
FLAX EXCELLENT 6.6-8.4 FAIR POOR EXCELLENT 1.52
WOOL POOR 0.8-2.0 FAIR GOOD FAIR 1.32
SILK GOOD 3.9-4.5 FAIR FAIR GOOD 1.30
RAYON-VISCOSE FAIR 0.7-6.0 FAIR POOR GOOD 1.54
ACETATE POOR 0.8-1.5 POOR POOR GOOD 1.32
TRIACETATE POOR POOR GOOD GOOD 1.30
ACRYLIC FAIR 1.8-3.5 POOR GOOD FAIR 1.19
GLASS EXCELLENT 6.0-7.0 POOR EXCELLENT EXCELLENT 2.54
NYLON EXCELLENT 2.5-7.5 EXCELLENT EXCELLENT POOR 1.14
POLYESTER EXCELLENT 2.5-9.5 EXCELLENT EXCELLENT POOR 1.38
SPANDEX POOR 0.6-0.9 POOR EXCELLENT EXCELLENT 1.21
ENVIRONMENTAL PROPERTIES OF FIBERS
Environmental properties or the various biological properties of fibers are important as it will determine the effect of various climatic conditions , micro organism and insects on textile products.Environmental or biological properties of fibers include:
1. SENSITIVITY TO THE CLIMATE
2. SENSITIVITY TO MICROORGANISMS
3. SENSITIVITY TO INSECTS
SENSITIVITY TO CLIMATE
Exposure to sunlight and air pollution will cause some fibers to deteriorate. for example cotton and flax looses its strength after long exposure to sunlight. white wool and silk turns yellow on prolonged exposure to sunlight.
SENSITIVITY TO MICROORGANISMS
Most synthetic fibers remain unaffected by microorganisms but fibers like cotton and regenerated cellulosic get discolored and eventually rots by microorganisms like mold and mildew
SENSITIVITY TO INSECTS Insects such as moths, carpet beetles and silverfish can
attack fibers. Wool is specially susceptible to attack from moths and carpet beetles. Silverfish will attack cotton and regenerated cellulosic fibres
THERMAL PROPERTIES OF FIBERS
Thermal properties of fibers are those properties which are exhibited by a fiber when they are exposed to heat directly or if exposed to similar conditions
Thermal properties of fiber include:
• EFFECTS OF HEAT
• FLAMMABILITY.
EFFECTS OF HEAT
• The reaction to heat may take the form of melting or shrinking.
• Different Fibers react differently to heat.
• The heating causes decomposition & weakens the fabric considerably.
• Most synthetic fibers are thermoplastic (fibers melt or soften when exposed to heat).
• The suitable treatment of fibers can give a fair degree of resistance to fiber.
FABRIC
COTTON
WOOL
SILK
VISCOSE RAYON
NYLON
POLYESTER
MIN & MAX (TEMP)
1500C & 2460C
2260C & 5720C
3300C & 3300C
3000C & 4000C
1500C & 2150C
2490C & 2900C
Heat Setting
• Applying heat and pressure in a controlled manner, permanently changes the shape and improves the dimensional stability of thermoplastic fibres.
• The fibers, yarns and fabrics are very stable at temperatures lower than those at which they were set.
FLAMMABILITYIt is the important factor considered for the
suitability to end use• Fibers react differently to flames.• Some fibers will ignite, some don't.• Cellulose fibers are most flammable ones. (cotton, flax, viscose)• Acetate and triacetate burn immediately • Nylon, polyester, acrylic, spandex don’t catch fire but melt and form hard beads
• Protein based wool & silk are less flammable. They burn slowly.
• The Inorganic fibers like asbestos, glass, and metal do not burn.
ELECTRICAL CONDUCTIVITY
• Fibers that do not conduct electrical charges create static electricity.
• Hydrophobic fibers tend to have low electrical conductivity because of their low absorbency.
• Synthetic fibers are poor conductors of electricity.
• Synthetic fiber materials are charged with static electricity so it attracts the dust & dirt particles and it becomes easily soiled
• The fabrics like cotton, wool and other fabrics retain moisture, the static leaks away to earth, just as fast as it is formed, via the metal parts of the machinery used & so causes no trouble.
CLASSIFICATION OF FIBRES
For the standardisation, classification and easier identification of fibres, Federal Trade Commission assigned generic groups of manufactured fibres according to their chemical composition.
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Flax | Cotton | Wool | Silk | Rayon | Acetate | Nylon | Polyester | Glass etc
NATURAL FIBRE• Any hair like raw material directly
obtainable from an animal, vegetable or mineral source that can be convertible after spinning into yarns and then into fabric.
• Under them there are various categories:
• (1) plant
• (2) animal
• (3) minerals
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Vegetable fibers they can be further on classified as:
(a) fibre occurring on the seed (raw cotton , java cotton)(b) phloem fiber (flax, ramie , hemp, jute)(c) tendon fibre from stem or leaves (manila hemp, sisal hemp etc)(d) fibre occurring around the trunk (hemp palm)(e) fibre of fruit/ nut shells (coconut fibre – Coir)cotton and linen are the most important among them.
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ANIMAL FIBRES
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• Animal fibers are natural fibers that consist largely of proteins such as silk, hair/fur, wool and feathers.
• The most commonly used type of animal fiber is hair.
MINERAL FIBRE
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• Asbestos is the only natural mineral fibre obtained from varieties of rocks.
• properties• It is fibrous form of silicate of
magnesium and calcium containing iron and aluminium and other minerals.
• It is acid proof, flame proof and rust proof.
• Its particles are carcinogenic and hence its use is restricted.
MAN MADE FIBRE
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• Natural man made fibre(A) Cellulosic fibres• Cellulose is one of many polymers found in nature. • Wood, paper, and cotton all contain cellulose. >
Cellulose is an excellent fiber.• Cellulose is made of repeat units of the monomer
glucose. • The three types of regenerated cellulosic fibres are
rayon, acetate and triacetate which are derived from the cell walls of short cotton fibres called linters.
• Paper for instance is almost pure cellulose
SYNTHETIC MAN MADE FIBRE
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• POLYESTER• Polyester is a category of
polymers which contain the ester functional group in their main chain.
• The term "polyester" is most commonly refered as polyethylene terephthalate (PET).
• it has a high melting temperature• it can be dyed with only disperse dyes• they are thermoplastic, have good
strength and are hydrophobic• the fibre has a rod like shape with a
smooth surface.• it is lustrous and its hand is crisp.• it has excellent resiliency and so it the
best wash and wear fabric.• there are problems of static and pilling in
it
NYLON
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• Nylon is one of the most common polymers used as a fiber.
• There are several forms of nylon depending upon chemical synthesis such as nylon 4, 6, 6.6, 6.10, 6.12, 8,10 and 11.
• Nylon is found in clothing all the time, but also in other places, in the form of a thermoplastic material.
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• Nylons are also called polyamides, because of the characteristic amide groups in the backbone chain.
• These amide groups are very polar and are linked with each other with hydrogen bonds.
• nylon is a regular and symmetrical fibre with crystalline regions and make very strong fibers.
• the fibre has a smooth rod like shape with a smooth surface
RUBBER FIBRE• Rubber is an elastic
hydrocarbon polymer that naturally occurs as a milky colloidal suspension, or latex, in the sap of some plants.
• The manufacturing process consists of extruding the natural rubber latex into a coagulating bath to form filament.the material is cross linked to obtain fibres which exhibit high stretch
• It can be synthesized.
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• natural rubber is essentially a polymer of isoprene units, a hydrocarbon diene monomer.
• Synthetic rubber can be made as a polymer of
• oprene or various other monomers• The material properties of natural
rubber make it an elastomer .• Rubber exhibits unique physical and
chemical properties.• Rubber's stress-strain behavior exhibits
the Mullins effect, the Payne effect and is often modeled as hyperelastic.
• Rubber strain crystallizes.
GLASS FIBRE• It is also known as Fiberglass that is a
material made from extremely fine fibers of glass. .Glass fiber is formed when thin strands of silica-based or other formulation glass is extruded into many fibers with small diameters suitable for textile processing
• it has a high degree of viscosity • The basis of textile grade glass fibers
is silica, SiO2. In its pure form it exists as a polymer, (SiO2)n.
• In order to induce crystallization, it must be heated to temperatures above 1200°C for long periods of time.
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• The first type of glass used for fiber was soda-lime glass or A glass which was not very resistant to alkali. A new type, E-glass was Glass fibers are useful because of their high ratio of surface area to weight. However, the increased surface area makes them much more susceptible to chemical attack.
• By trapping air within them, blocks of glass fiber make is used as a reinforcing agent for many polymer products.
• it has a good thermal insulation, with a thermal conductivity of 0.05 W/m-K.
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• Because glass has an amorphous structure, its properties are the same along the fiber and across the fiber.
• Humidity is an important factor in the tensile strength. Moisture is easily adsorbed, and can worsen microscopic cracks and surface defects, and lessen tenacity.
• it has no effect on exposure to sunlight even after extended periods.
• It is completely hydrophobic
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METALLIC FIBRES• Metallic fibers are
manufactured fibers composed of metal, plastic-coated metal, metal-coated plastic, or a core completely covered by metal. Gold and silver have been used since ancient times as yarns for fabric decoration. More recently, aluminum yarns, aluminized plastic yarns, and aluminized nylon yarns have replaced gold and silver.
• they are made through laminating process.
• Coated metallic filaments help to minimize tarnishing.
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• When suitable adhesives and films are used, they are not affected by salt water, chlorinated water in swimming pools or climatic conditions.
• If possible anything made with metallic fibers should be dry-cleaned.
• Ironing can be problematic because the heat from the iron, especially at high tempatures, can melt the fibers.
• they are used mainly for decorative purposes.
Fiber Identification
test
fiber
Soda ash
40% sol.
Caustic soda 25% sol.
Sodium hypo chloride
Hydro chloric acid
40%
Nitric acid
15%
Nitric acid
70%
Sulphuric acid
15%
Sulphuric acid
70%
Burning in Flame
Microscopic
View
Remarks
Cotton swells Swells&
Shines
Whitened Turns yellowish
Opens up &looses strength
Dissolves slowly
Dissolves on heating
Dissolves quickly
Burns continuously leaving grey ash of burning paper smell
Longitudinal twists. Resistance to alkalis.
jute -do- -do- -do- ---
-
--- -do -do Dissolves -do Longitudinal irregular lines
-Rough handle
Coir --- --- Color turns pale
--- --- --- Dissolves on prolonged heating
Dissolves slowly
-do-
black ash
Opaque thick serations
Brittle & resistant to chemicals
Viscose Swells Swells & slowly dissolves
Gets weakened
Turns yellow
Dissolves on heating
Dissolves Dissolves Dissolves
quickly
Burns continuously leaving grey ash of burning paper smell
Longitudinal regular lines
Soft filaments good luster
Silk Looses strength
Dissolves Dissolves slowly
--- --- Dissolves partial;ly
--- Dissolves Self extinguishing
Leaves crushable
Black beads
Densed centre line Uneven
coating
Delicate lustrous
filaments
Wool -do- -do- Dissolves --- --- Dissolves slowly
--- Dissolves slowly
Self extinguishing
Leaves crushable
Black beads
Fish
Scales
structure
Rough crimpy
fibers
Polyester --- --- --- --- --- Dissolves slowly on prolonged treatment
transperant hard beads.
Dissolves slowly
Burns& stops leaving semi
Translucent& uniform
Resistant to chemicals
Acrylic --- --- --- --- --- Looses strength
& dissolves slowly
--- Turns yellowish brown
Dissolves & Turns yellowish brown
Burns & stops
Out of flame Leaving dark hard beads
Translucent& uniform
Lofty & more voluminous
Nylon --- --- --- --- --- Looses strength
--- Dissolves slowly
Burns & stops
Out of flame Leaving dark hard beads
Translucent& uniform
Strong
More elastic
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