Fibre Properties Flashcards

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What is lustre in fabric?

gloss, sheen, sparkle or shine of a fabric caused by light reflecting from the surface

What is drape in fabric?

how a fabric hangs or falls

What is abrasion resistance?

ability to withstand rubbing or wear and tear

What is strength in fabric?

ability to resist breaking

What is absorbency?

ability to absorb moisture

What is elasticity in fabric?

ability to return to original shape after being stretched or compressed

What are thermal properties in fabric?

ability to withstand and transfer heat

What is dimensional stability in fabric?

inability to shrink or stretch

What is the effect of chemicals on fabric?

ability to withstand acids, alkalis and solvents

What is sun resistance in fabric?

ability to withstand deterioration when exposed to sunlight

What is color fastness in fabric?

ability to withstand color change after exposure to heat or water

What is shrink resistance in fabric?

inability to contract

What are amorphous regions in a fiber's internal structure?

random arrangement of polymers with large distances

What are the characteristics of fibers with high amorphous regions?

poor strength, low durability, good absorbency, easily dyed

What are crystalline regions in a fiber's internal structure?

polymers packed closely together in a parallel arrangement

What are the characteristics of fibers with high crystalline regions?

strength, high durability, low absorbency, not easily dyed

How does cross-section affect lustre?

reflect light vs. scatter it

How does cross-section affect insulation?

ability to hold pockets of air, holding body heat

How does density ratio of surface area to volume affect fibres?

affects moisture transfer (wicking) properties

What are staple fibers?

short fibers

What are filament fibers?

long or continuous fibers

What does the longitude of a fibre refer to?

fiber length, diameter, ridges/edges/scales

What is cotton known for?

durability, appearance and natural comfort

What are cotton fibers made of?

cellulose

What is the length of cotton staple fibers?

10–65 mm

What colors are cotton fibres usually?

white to beige

What is the natural lustre of cotton fibres?

fibers are not naturally lustrous

What finishing treatment results in low lustre in cotton?

mercerisation

What is the drape like on cotton?

poor but can be improved depending on fabric construction

What is the abrasion resistance of cotton?

moderate to good depending on fabric structure

What is the strength of cotton fibres?

relatively strong due to the intricate fibre structure and highly crystalline regions (70%)

How does water affect the strength of cotton fibres?

becomes stronger when wet

What is the absorbency of cotton?

highly absorbent, holding up to 27 times its own weight in water

What is the thermal property of cotton?

cool fiber

What is he dimensional stability like for cotton garments?

retains their shape due to the inelasticity of the fibre

What is the effect of acids on cotton fibres?

broken down by strong acids

What is the effect of alkalis on cotton fibres?

resistant to alkalis

What is the sun resistance of cotton fibres?

not easily damaged by sunlight

What does hydrophilic mean for cotton fibres?

easily dyed

what is the shrink resistance of cotton fibres?

tends to shrink when dried after washing

How does cotton react to flame approach in a burn test?

doesn’t shrink away

How does cotton react inside a flame in a burn test?

burns quickly with yellow flame

How does cotton react when removed from a flame in a burn test?

continues to burn; afterglow

What kind of ash/residue is left after burning cotton?

light grey ash

What is the smell of burning cotton?

similar odour to burning paper

What are the amorphous properties of Cotton microscopically?

low amorphous regions – 30%

What are the crystalline properties of Cotton microscopically?

highly Crystalline 70%

What is the longitude of cotton fibre microscopically?

irregular ribbon-like twists called convolutions

Where does wool come from?

fleece of domesticated sheep

What is the colour of wool fibres?

off-white to light cream

What is the lustre of wool fibres?

Not typically lustrous

What is the drape like of wool?

Exceptional, making it perfect for all types of apparel and furnishings

What is the abrasion resistance of wool fibres?

Moderate, due to the fibre scale construction and excellent elasticity

What is the strength of wool fibres?

Weak, due to the fibre’s highly amorphous structure

What is the absorbency of wool fibres?

Extremely absorbent due to the fibre’s amorphous regions

What is the elasticity of wool fibres?

Excellent elastic recovery

What is the heat conductivity of wool fibres?

Poor conductor of heat, so is known as a warm fibre

What is the dimensional stability of wool fibres?

Poor dimensional stability

What affect do chemicals have on wool?

Resistant to acids but is weakened by alkalis and damaged by chlorine bleach

What is the sun resistance of wool fibres?

Sunlight yellows wool over time and weakens the fibre

What is the colour fastness of wool fibres?

Excellent – wool is dyed readily due to its highly amorphous structure

What is the shrink resistance of wool fibres?

Poor shrink resistance

How does wool react to approach of a flame?

Shrinks away from flame

How does wool react inside of a flame?

Smoulders and burns slowly

How does wool react when removed from a flame?

Tends to self-extinguish

What kind of ash is left from burning wool?

Crushable black ash

What is the smell of wool when burned?

Similar odour to burning hair

How amorphous is wool microscopically?

Highly amorphous – 70%

How crystalline is wool microscopically?

Low crystallinity – 30%

What is the cross section of wool fibres?

Oval

What is the longitude of wool fibres?

overlapping surface cells called scales

What are silk fibres?

Fine, long filament fibres that are wound up inside the cocoons of silk moth larvae

What is the lustre like for silk?

Highly lustrous

What is the drape for silk?

Exceptional, making it perfect for all types of apparel and furnishings

What is the abrasion resistance of silk?

Good. Abrasion resistance depends on the construction and fineness of fabric

What is the strength of silk?

One of the strongest natural fibers

What are the thermal properties of silk?

Low Thermal Properties
Excellent air permeability and thermoregulation

What is the chemical resistance of silk?

Average chemical resistance

What is the sun resistance of silk?

Quickly destroyed by exposure to sunlight

What is the shrink resistance of silk?

Does not shrink

How does silk react to approach of a flame?

Slow to light

How does silk react inside of a flame?

Slowly smouldering

How does silk react when removed from a flame?

Burning stops when the fire is removed

What kind of ash is formed by burning silk?

black ash is formed

What is the smell of burning silk?

burnt hair or burnt feathers

How amorphous is silk microscopically?

Low amorphous regions – 30%

How crystalline is silk microscopically?

Highly Crystalline – 70%