Textile fibres

Know About Textile Fibres

Bulletin Post 09

Contents

Fibre Classification
Natural Fibres
Man-made Fibres
Textile Fibre Parameters
Fibre Properties – Comparison

Introduction

Textiles have such an important bearing on our daily lives that everyone should know something about the basics of fibres and their properties.

Textile fibres are used for a wide range of applications such as covering, warmth, personal adornment and even to display personal wealth.

Textile technology has come a long way in meeting these requirements. A basic knowledge of textile fibres will facilitate an intelligent appraisal of fibre brands and types and help in identifying the right quality for the application.

This bulletin covers various textile fibres and the properties that are important for a suitable textile application.

Fibre Classification

Textile fibres can be broadly classified into two categories:

  • Natural fibres
  • Man-made fibres

Natural Fibres

Natural fibres are subdivided further, as outlined below, by their origin.

Table below when available.

Fibre name Source Composition
Vegetable
 Cotton Cotton boll Cellulose
 Kapok Kapok tree Cellulose
 Linen Flax stalk Cellulose
 Jute Jute stalk Cellulose
 Hemp Hemp or Abaca  Cellulose
 Ramie Rhea and China Cellulose
 Sisal Agave leaf Cellulose
 Coir Coconut husk Cellulose
 Pina Pineapple leaf Cellulose
Animal
Wool Sheep  Protein 
Silk  Silkworms  Protein  
Hair  Hair bearing animals Protein  
Mineral
Asbestos Varities of rock Silicate of Magnesium and Calcium

Man-made Fibres

Man-made fibres are subdivided as shown below with their various compositions and origin. 

Fibre Name Source
Cellulosic
Rayon Cotton linters or wood
Acetate Cotton linters or wood
Tri-acetate Cotton linters or wood
Non-Cellulosic Polymers
Nylon Aliphatic polyamide
Aramid Aromatic polyamid
Polyester Dihydric alcohol and terephthalic acid
Acrylic Acrylonitrile
Modacrylic Acrylonitrile
Spandex Polyurethene
Olefin Ethylene or propylene
Vinyon Vinyl chloride
Saran Vinylidene chloride
Novoloid Phenol based navolac
Polycarbonate Carbonic acid (polyester derivative)
Fluorocarbon Tetrafluoroethylene
Protein
Azlon Corn, soybean, etc.
Rubber
Rubber Natural or synthetic rubber
Metallic
Metal Aluminum, silver, gold, stainless steel
Mineral
Glass Silica sand, limestone, other minerals
Ceramic Aluminium, silica
Graphite Carbon

1. Natural Fibres

Cotton

Cotton, the natural fibre most widely used in apparel, grows in a boll around the seeds of cotton plants. A single fibre is an elongated cell that is a flat, twisted, hollow, ribbon-like structure.

Cotton plant

Characteristics

  • Fair to good strength
  • Very little elasticity
  • Less resilient and prone to wrinkling
  • Comfortable and soft feel
  • Good absorbency
  • Conducts heat well
  • Damaged by insects, mildew, rot and moths
  • Weakened by extended sunlight exposure

Applications

  • Widely used in number of textile products
  • Commonly used in woven and knitted apparel
  • Home textile – bath towels, bath robes, bed covers etc.
  • Used as a blend with other fibres as rayon, polyester, spandex etc.

Linen

Linen, one of the most expensive natural fibres, is made from the flax plant. It is labour-intensive to produce, hence produced in small quantities. However linen fabric is valued for its exceptional coolness and freshness in hot weather.

Cricket ball

It is composed of 70% cellulose and 30% pectin, ash, woody tissue and moisture.

Characteristics

  • Strongest vegetable fibre
  • Poor elasticity, hence wrinkles easily
  • Relatively smooth, becomes softer when washed
  • Highly absorbent
  • Good conductor of heat and feels cool
  • Lustrous
  • More brittle, constant creasing in the sharp folds, tends to break
  • Damaged by mildew, perspiration and bleach
  • Resistant to moths and carpet beetles

Applications

  • Apparel - suits, dresses, skirts, shirts etc.
  • Home and commercial furnishing items – table cloths, dish towels, bed sheets, wallpaper / wall coverings, window treatments etc.
  • Industrial products - luggage, canvas etc.
  • Used as blend with cotton

Wool

Wool fibre grows from the skin of sheep and is a relatively coarse and crimped fibre with scales on its surface. It is composed of protein. The fibre appearance varies depending on the breed of the sheep. Finer, softer and warmer fibres tend to be with more and smoother scales. Thicker, less warm fibres have fewer and rougher scales. Normally, the better wool fibres with finer scales are duller in appearance than the poorer quality fibres which have fewer scales.

Dyed new wool

Characteristics

  • Crimped in appearance
  • Elastic
  • Hygroscopic, readily absorbs moisture
  • Ignites at a higher temperature than cotton
  • Lower rate of flame spread, heat release and combustion heat
  • Resistant to static electricity

Applications

  • Clothing – jackets, suits, trousers, sweaters, hats etc.
  • Blankets, carpets, felt and upholstery
  • Horse rugs, saddle cloths

Silk

Silk is a fine, continuous strand unwound from the cocoon of a moth caterpillar known as the silkworm. It is composed of protein. It is very shiny due to the triangular prism-like structure of the silk fibre, which allows silk cloth to refract incoming light at different angles.

Silk pillows

Characteristics

  • Lustrous, smooth and soft texture and not slippery
  • Lightweight, strong, but can lose up to 20% of its strength when wet
  • Elasticity is moderate to poor. If elongated, it remains stretched
  • Can be weakened if exposed to too much sunlight
  • May be affected by insects, especially if left dirty
  • Can regain up to 11% of its moisture

Applications

  • Shirts, ties, blouses, formal dresses, high-fashion clothes
  • Lingerie, pyjamas, robes, dress suits and sun dresses
  • Many furnishing applications
  • Upholstery, wall coverings, and wall hangings

Other Natural Fibres

Jute

Jute is taken from a tall plant of the same name and it is easy to cultivate and harvest. It is the cheapest fibre and is used in great quantities.

Characteristics

  • It is not durable as it deteriorates rapidly when exposed to moisture
  • Less strength
  • Cannot be bleached to make it pure white due to lack of strength

Applications

  • Binding threads for carpets, coarse and cheap fabrics, heavy bagging etc.

Kapok

It is a white hair-like fibre obtained from the seed capsules of plants and trees called Ceiba Pentandra grown in Java and Sumatra (Indonesia), Mexico, Central America and the Caribbean, Northern South America and tropical West Africa.

It is called silk cotton due to its high lustre which is equal to that of silk.

Characteristics

  • Smooth texture
  • Very lustrous
  • Weak
  • Short fibre length
  • Resistant to moisture, dries quickly when wet

Applications

  • Mattresses, cushions, upholstered furniture

Ramie

A woody fibre resembling flax and it is also known as rhea and China grass. It is taken from a tall flowering plant.

Embroidered fabric and alcazar cones

Characteristics

  • Stiff
  • More brittle
  • Lustrous

Applications

  • Canvas, upholstery, clothing, etc.

2. Man-made Fibres

2.1. Man-made (Regenerated)

Cellulosic

They are derived either from the cellulose of the cell walls of short cotton fibres that are called linters or, more frequently from pine wood. There are three types of man made cellulosic fibres: Rayon, acetate and tri-acetate.

Rayon

Rayon [link to Raylon] is made from naturally occurring polymers that simulate natural cellulosic fibres. It is neither a truly synthetic fibre nor a truly natural fibre.

There are two varieties of Rayon; viscose and high wet modulus (HWM). These in turn are produced in a number of types to provide certain specific properties.

Characteristics

  • Soft, smooth and comfortable
  • Naturally high in lustre
  • Highly absorbent
  • Durability and shape retention is low, especially when wet
  • Low elastic recovery
  • Normally weak, but HWM rayon is much stronger, durable and has good appearance retention.

Applications

  • Apparel - blouses, dresses, jackets, lingerie, linings, suits, neck ties etc.
  • Furnishing items - bedspreads, bed sheets, blankets, window treatments, upholstery etc.
  • Industrial uses e.g. medical surgery products, non-woven products, tyre cord etc.
  • Other uses - feminine hygiene products, diapers, towels etc.

Acetate

Acetate consists of a cellulose compound identified as acetylated cellulose – a cellulose salt. Hence it possesses different qualities compared to rayon.

Acetate is thermoplastic and can be formed into any shape by application of pressure combined with heat. Acetate fibres have good shape retention.

Characteristics

  • Thermoplastic
  • Good drapability
  • Soft, smooth and resilient
  • Wicks and dries quickly
  • Lustrous appearance
  • Weak, rapidly loses strength when wet, must be dry-cleaned
  • Poor abrasion resistance

Applications

  • Primarily in apparel - blouses, dresses, jackets, lingerie, linings, suits, neck ties, etc.
  • Used in fabrics such as satins, brocades, taffetas, etc.

Tri-acetate

Tri-acetate consists of acetylated cellulose that retains acetic groupings, when it is being produced as triacetate cellulose. It is a thermoplastic fibre and is more resilient than other cellulosic fibres

Characteristics

  • Thermoplastic
  • Resilient
  • Shape retentive and wrinkle resistant
  • Shrink resistant
  • Easily washable, even at higher temperatures
  • Maintains creases and pleats well

Applications

  • Primarily apparel
  • Used in clothing where crease / pleat retention is important e.g. skirts and dresses
  • Can be used with polyester to create shiny apparel

2.2. Man-made – Non-cellulosic

Polymer Fibres

This group of fibres is distinguished by being synthesised or created from various elements into larger molecules that are called linear polymers.

The molecules of each particular compound are arranged in parallel lines in the fibre. This arrangement of molecules is called molecular orientation.

The properties of such fibres are dependent on their chemical composition and kinds of molecular orientation.

Nylon

In nylon, the fibre forming substance is a long-chain synthetic polyamide in which less than 85% of the amide linkages are attached directly to two aromatic rings. The elements carbon, oxygen, nitrogen and hydrogen are combined by chemical processes into compounds which react to form long-chain molecules, chemically known as polyamides and are then formed into fibres. There are several forms of nylon. Each depends upon the chemical synthesis.

Outdoor Goods

They are: Nylon 4; 6; 6.6; 6.10; 6.12; 8; 10; and 11.

Characteristics

  • Highly resilient
  • High elongation and elasticity
  • Very strong and durable
  • Excellent abrasion resistance
  • Thermoplastic
  • Has the ability to be very lustrous, semi-lustrous or dull
  • Resistant to insects, fungi, mildew and rot

Applications

  • Apparel – pantyhose, stockings, leggings, etc.
  • Home furnishing
  • Industrial applications - parachutes, tyre cords, ropes, airbags, hoses, etc.

Polyester

In polyester, the fibre forming substance is any long-chain synthetic polymer composed of at least 85% by weight of an ester of a substituted aromatic carboxylic acid, but not restricted to substituted terapthalate units and para-substituted hydroxybenzoate units.

In producing such fibres, the basic elements of carbon, oxygen and hydrogen are polymerised. Variations are possible in the methods of production, in the combination of ingredients and in the ultimate molecular structures of the fibre forming substance.

Characteristics

  • Thermoplastic
  • Good strength
  • Hydrophobic (non absorbent)

Applications

  • Apparel – woven and knits, shirts, pants, jackets, hats etc.
  • Home furnishing – bed sheets, blankets, upholstered furniture, cushioning material
  • Industrial uses – conveyor belts, safety belts, tyre reinforcement

Spandex

The fibre forming substance used to produce spandex is any long-chain synthetic polymer composed of at least 85% of segmented polyurethane. Variations are possible when producing this fibre.

The basic elements of nitrogen, hydrogen, carbon and oxygen are synthesised with other substances to ethyl ester compounds in polymer chains of soft segments or sections that provide stretch and harder segments that hold the chain together.

Trademarks of three spandex fibres are Cleer-span, Glospan and Lycra.

Characteristics

  • Highly elastic
  • Comfortable
  • High shape retention
  • Durable

Applications

  • Never used alone, but always blended with other fibres
  • Apparel and clothing items with stretch for comfort and fit
  • Hosiery
  • Foundation garments
  • Swimwear, athletic, aerobic apparel
  • Lingerie, leggings and socks
  • Shaped garments e.g. bra cups
  • Gloves

Acrylic

In acrylics, the fibre forming substance is any long chain polymer composed of at least 85% by weight of acrylonitrile units. Using complicated processes, carbon, hydrogen and nitrogen, the basic elements are synthesised with small amounts of other chemicals into larger polymer combinations. Variations are possible in the methods of production, in the combination of ingredients and in the ultimate molecular structures of the fibre forming substance.

Sofa

Characteristics

  • Soft, warm handling characteristics similar to wool
  • Resilient
  • Shape retentive

Applications

  • Apparel
  • Home furnishing

3. Man-made – Protein Fibres

The protein from such products as corn and milk has been processed chemically and converted into fibre. However, such fibres are not commercially successful.

4. Man-made – Rubber Fibres

The fibre forming substance is comprised of natural and synthetic rubber. The treated rubber is produced in strands, so that the cross-section is either round or square and the longitudinal surface is relatively smooth.

5. Man-made – Metallic Fibres

These fibres are composed of metal, plastic-coated metal, metal-coated plastic, or a core completely covered by metal. These fibres are usually produced in flat, narrow, smooth strips which possess high lustre.

Iridescent

Applications

  • Decorative yarns in apparel and home furnishing items.

6. Man-made – Mineral Fibres

Various minerals have been manufactured into glass, ceramic and graphite fibres having prescribed properties for specific uses.

Glass

Although glass is a hard and inflexible material, it can be made into a fine, translucent textile fibre that has an appearance and feel of silk.

Natural minerals such as silica sand, limestone, soda ash, borax, boric acid, feldspar and fluorspar have been fused under very high temperatures into glass which is processed into a fibre.

Characteristics

  • Inert
  • Highly flame resistant

Applications

  • Heat resistant industrial applications

Textile Fibre Parameters

Fibrous materials should possess certain properties to become a suitable textile raw material. Properties which are essential for acceptance as a suitable raw material may be classified as ‘primary properties’. The other properties which add specific desirable character or aesthetics to the end product and its use may be classified as ‘secondary properties’.

Primary Properties

1. Length

2. Tenacity (strength)

3. Flexibility

4. Cohesion

5. Uniformity of properties

Secondary Properties

1. Physical shape

2. Specific gravity (influence weight, cover etc.)

3. Moisture regain and absorption (comfort, static electricity etc.)

4. Elastic character

5. Thermo plasticity (softening point and heat - set character)

6. Dyeability

7. Resistance to solvents, corrosive chemicals, micro-organisms and environmental conditions

8. Flammability

9. Lustre

Physical Properties

Cotton

Property Characteristics
Microscopic appearance Flat, twisted and ribbon-like
Length Staple fibre, length ranges from 1 to 5.5 cm
Colour Creamy white in natural form, unless treated
Lustre Medium, unless treated for lustre
Strength Fair
Elasticity Low
Resilience Low
Moisture absorption Excellent
Heat Will withstand moderate heat / Decomposes after prolonged exposure to temperatures of 150°C / 320°F or over
Flammability Burns readily

Linen

Property Characteristics
Microscopic appearance Cross-section is made up of irregular polygonal shapes
Length Long staple, 25 to 120 cms
Colour Off white
Lustre High
Strength Good
Elasticity Low
Resilience Little
Moisture absorption Good
Heat Will withstand moderate heat
Flammability Scorches and flames readily 

Wool

Property Characteristics
Microscopic appearance Crimped
Length Staple fibre, up to 40 cms
Colour Generally creamy white, some breeds of sheep produce natural colours such as black, brown, silver, and random mixes.
Lustre High
Strength High
Elasticity Good
Resilience High
Moisture absorption Tends to repel initially, but good absorption.
Heat Becomes harsh at 100°C / 212°F, decomposes at slightly higher temperatures.
Flammability Scorches at 204°C / 400°F, will char

 Silk

Property Characteristics
Microscopic appearance Triangular prism-like structure
Length Continuous filament
Colour Usually off white, and also shades of pale beige, brown, and grey
Lustre Excellent
Strength Good
Elasticity High
Resilience High
Moisture absorption Good
Heat Sensitive and gets decomposed
Flammability Burns at 165°C / 330°F

Rayon

Property Characteristics
Microscopic appearance

Striations seen in viscose and high strength rayon

If delustred, scattered specks of pigment can be seen

Length Filament and Staple
Colour Transparent unless dyed
Lustre High
Strength

Fair to excellent
Regular rayon has fair strength
High tenacity types have good strength

Elasticity

Regular rayon: low
High strength rayon: good

Resilence High wet strength rayon is better
Moisture absorption

Higher than natural cellulose
Fibres swell in water
Weaker when wet

Heat

Loses strength above 148°C / 300°F
Decomposes between 176°C / 350°F and 204°C / 400°F

Flammability Burns rapidly unless treated
Electrical conductivity Fair – static charge can be reduced with special finishes

Acetate

Property Characteristics
Microscopic appearance

Striations farther apart than viscose rayon
Lobed cross-section

Length Filament and staple
Colour Transparent unless dulled by pigments
Lustre Bright, semi bright or dull
Strength Moderate, less than rayon when it is wet
Elasticity Not very high, similar to rayon
Resilience Poor
Moisture absorption 6%, little strength loss when it is wet
Heat Ironing temperatures of 135°C / 275°F are satisfactory
Flammability Slowly combustible
Electrical conductivity Good

Nylon

Property Characteristics
Microscopic appearance Very smooth and even
Length Filament and staple
Colour Off white
Lustre High natural lustre that can be controlled
Strength Exceptionally high
Elasticity Exceptionally high
Resilience Very good
Moisture absorption 3.8%
Heat High resistance, melts at 250°C / 482°F
Flammability Melts slowly Does not support combustion
Electrical conductivity Low, generates static

Polyester

Property Characteristics
Microscopic appearance Smooth, even, rod like, different cross sectional shapes
Length Filament and staple
Colour White
Lustre Bright or dull
Strength Good to excellent
Elasticity Fair to good
Resilience Excellent
Moisture absorption Less than 1%
Heat Softening or sticking temperature is above 204°C / 400°F
Flammability Burns slowly
Electrical conductivity Accumulates static charges

Acrylic

Property Characteristics
Microscopic appearance Uniform and smooth surface Irregular spaced striations
Length Mainly a staple fibre
Colour White
Lustre Bright or dull
Strength Fair to good strength
Elasticity Good
Resilience Good
Moisture absorption 1 - 3%
Heat

Yellowing may occur above 148°C / 300°F
Softening or stocking about 232°C / 450°F

Flammability Burns with yellow flame
Electrical conductivity Fair to good

Fibre Properties - Comparison

Absorbency

Fibre Moisture regain*
Cotton 7 -11
Flax 12
Silk 11
Wool 13 - 18
Acetate 6.0
Acrylic 1.3 - 2.5
Aramid 4.5
Glass 0 - 0.3
Nylon 4.0 - 4.5
Polyester 0.4 - 0.8
Rayon 15
Rayon HWM 11.5 - 13
Spandex 0.75 - 1.3

*Moisture regain is expressed as a percentage of the moisture-free weight at 70º Fahrenheit and 65% relative humidity.

Thermal properties

Fibre Melting Point Softening Sticking Point Safe Ironing Temperature
˚F ˚C ˚F ˚C ˚F ˚C
Cotton Non melting 425 218
Flax Non melting 450 232
Silk Non melting 300 149
Wool Non melting 300 149
Acetate 446 230 364 184 350 177
Acrylic 400 - 490 204 - 254 300 - 350 149 - 176
Aramid Does not melt, carbonises above 426°C / 800°F
Glass 1400 - 3033
Nylon 6 414 212 340 171 300 149
Nylon 66 482 250 445 229 350 177
Polyester PET 480 249 460 238 325 163
Polyester PCDT 550 311 490 254 350 177
Rayon Non melting 375 191
Spandex 446 230 347 175 300 149

Effects of Acids

Fibre Behaviour
Cotton Disintegrates in hot dilute and cold concentrated mineral acids
Linen Disintegrates in hot dilute and cold concentrated acids
Wool Destroyed by hot sulphuric, otherwise unaffected by acids
Silk Organic acids do not harm, concentrated mineral acids will dissolve
Rayon Disintegrates in hot dilute and cold concentrated acids
Acetate Soluble in acetic acid, decomposed by strong acids
Tri-acetate Soluble in acetic acid, decomposed by strong acids
Nylon Decomposed by strong mineral acids, resistant to weak acids
Polyester Resistant to most mineral acids; disintegrated by 96% sulphuric acid
Spandex Resistant to most mineral acids, some discolouration can happen
Acrylic Resistant to most acids
Glass Resistant to most acids

Effects of Alkalis

Fibre Behaviour
Cotton Not harmed by alkalis
Linen Highly resistant
Wool Attacked by weak alkalis, destroyed by strong alkalis
Silk Damaged only under high temperature and concentration
Rayon Disintegrates in concentrated solutions
Acetate Not affected, unless high concentration and temperature is applied
Tr-acetate Not affected, unless high concentration and temperature is applied
Nylon Little or no effect
Polyester Resistant to cold alkalis, slowly decomposed at a boil by strong alkalis
Spandex Affected
Acrylic Destroyed by strong alkalis at boil, resists weak alkalis
Glass Attacked by hot weak alkalis and concentrated alkalis

Effects of Organic Solvents

Fibre Behaviour
Cotton Oxidises, turning yellow and losing strength on long exposure
Linen Resistant than cotton, gradually deteriorate from prolonged exposure
Wool Strength loss due to prolonged exposure
Silk Continuous exposure weakens
Rayon Generally resistant, loses strength after long exposure
Acetate Approximately same as rayon
Tri-acetate Resistant, loses strength after long exposure
Nylon Good resistance
Polyester Good resistance
Spandex Generally not affected, prolonged exposure weakens
Acrylic Little or no effect

Effects of Sunlight

Fibre Behaviour
Cotton Oxidises, turning yellow and losing strength on long exposure
Linen Resistant than cotton, gradually deteriorate from prolonged exposure
Wool Strength loss due to prolonged exposure
Silk Continuous exposure weakens
Rayon Generally resistant, loses strength after long exposure
Acetate Approximately same as rayon
Tri-acetate Resistant, loses strength after long exposure
Nylon Good resistance
Polyester Good resistance
Spandex Generally not affected, prolonged exposure weakens
Acrylic Little or no effect

Cleanliness and Washability

Fibre Behaviour and effect
Cotton Launders well and gives up dirt easily
Linen Launders well and gives up dirt easily
Wool Attracts dirt, unless thoroughly cleaned it retains odors
Silk Prevents dirt from settling. Smooth surface allows stains to be easily washed away
Rayon Prevents dirt from settling. Smooth surface allows stains to be easily washed away
Acetate Prevents dirt from settling. Smooth surface allows stains to be easily washed away
Tri-acetate Prevents dirt from settling. Smooth surface allows stains to be easily washed away
Nylon 6.6 Prevents dirt from settling. Smooth surface allows stains to be easily washed away
Polyester Prevents dirt from settling. Smooth surface allows stains to be easily washed away
Spandex Launders well
Acrylic Launders well

Effects of Perspiration

Fibre Behaviour
Cotton Resistant to alkali perspiration, slight deteriorating effect with acid perspiration
Linen Resistant to alkali perspiration, slight deteriorating effect with acid perspiration
Wool

Weakened by alkali perspiration

Discolouration happens in general with perspiration

Silk Deteriorates and Colour is affected causing stains
Rayon Fairly resistant to deterioration
Acetate Good resistance
Tri-acetate Good resistance
Nylon 6.6 Resistant, Colour may be affected
Polyester Resistant
Spandex Good resistance to degradation
Acrylic No deterioration

*Perspiration can be acidic or alkaline, depending on the individual's metabolism.

Effects of Mildew

Fibre Behaviour and effect
Cotton Affected in a damp condition
Linen Affected in a damp condition
Wool Not susceptible in ordinary condition, but in damp condition
Silk Not susceptible in ordinary condition, but in damp condition
Rayon Affected in a damp condition
Acetate Highly resistant
Tri-acetate Extremely high resistance
Nylon No effect
Polyester Absolutely resistant
Spandex Good to excellent resistance
Acrylic

May form, but will have no effect

Can be easily wiped off

Effect of Heat

Fibre Behaviour and effect
Cotton

Withstand moderate heat

Will scorch and burn with prolonged exposure to high heat

Linen

Withstand moderate heat

Will scorch and burn with prolonged exposure to high heat

Wool Not easily combustible, becomes harsh at 100°C / 212°F and will scorch at 204°C / 400°F and eventually char
Silk Sensitive to heat, decomposes at 165°C / 330°F
Rayon Behaves similar to cotton as a cellulosic fibre
Acetate Thermoplastic in nature, gets sticky at 176°C / 350°F and becomes stiff later
Tri-acetate Thermoplastic in nature, gets sticky at 298°C / 570°F and becomes stiff later
Nylon Will melt under high temperature, Nylon 6 melts at 215°C / 420°F and Nylon 6, 6 248°C / 480°F
Polyester

Will melt under high temperature

Becomes sticky at 226°C / 440°F to 243°C / 470°F and melts and flames at 248°C / 480°F to 290°C / 554°F depending on its type

Spandex Yellows and loses elasticity and strength at over 148°C / 300°F, sticks at 175°C / 347°F and melts at 230°C / 446°F
Acrylic Becomes sticky at 229°C / 455°F and melts at higher temperature

Effects of Insects

Fibre Behaviour and effect
Cotton Not damaged
Linen Not damaged
Wool Vulnerable to moths and carpet beetles
Silk May be attacked by larvae of cloth moths or carpet beetles
Rayon Not attracted
Acetate Not attracted
Tri-acetate Not attracted
Nylon Unaffected
Polyester Unaffected
Spandex Unaffected
Acrylic Unaffected