Fibre Qualities

Comparative Characteristics

FibreTenacity of dry fibre (gm/denier)Wet strength compared to dry strengthRope shock load absorptionSpecific GravityAble to floatStrength/ Weight ratio (av.)Elongation & Creep
Sisal4-5Up to 120%Poor1.5No Fibre elongation: Dry 2.9%, Wet 3.4%.
Rope elongation: Dry 13%, Wet 16%.
Extension causes rupture.
Manila5-6Up to 120%Poor1.5No Fibre elongation: Dry 2.8%, Wet 3.2%.
Rope elongation: Dry 13%, Wet 15%.
Extension causes rupture.
Polyethylene6100%Good0.95Yes2.10High tenacity. Good recovery after stretch and extension at break of 50%. High creep.
Polypropylene6.5100%Very Good0.91Yes2.50High tenacity. Good recovery from stretch and elongation at break for ropes is 25-30%. High creep.
HT Polyester7-10100%Very Good1.38No2.25Elongation 35% at break. Low creep.
Nylon985-90%Excellent1.14No3.00Elongation Dry 40%. Wet 35%.
Moderate creep.
Aramid (Kevlar®)18-2695%Fair1.44No Elongation 4% at break. Very low creep.
Technora®28100% 1.39No Elongation 4.5% at break. Low creep.
UHMwPE28100% 0.97Yes Elongation 2-5% at break.


Chemical Resistance & Degradation

FibreEffects of acidsEffects of AlkalisEffect of Organic SolventsUV resistance in sunlightOtherResistance to aging* 
SisalDegradation of acids in high concentration or temperature. ResistantResistantGoodDegradation by sea water, paints, detergents, chemical salts and fatsGood
ManilaDegradation of acids in high concentration or temperature. Degradation by alkalis.ResistantGoodDegradation by paints, detergents, chemical salts and fatsGood
PolyethyleneVery resistantVery resistantSoluble in hot chlorinated hydrocarbons.Good (UV stabilised) Excellent
PolypropyleneVery resistantVery resistantSoluble in chlorinated hydrocarbons.Good (UV stabilised) Excellent
HT PolyesterResistant to most mineral acids. Disintegrated by 95% sulphuric acid.No effect cold. Slowly disintegrated by strong alkalies at the boil.Generally unaffected. Soluble in some phenolic compounds.Excellent Excellent
NylonDecomposed by strong mineral acids. Resistant to weak acids. Little or noneResistant, soluble in some phenolic compounds and in 90% formic acid.Good Excellent
Aramid (Kevlar®)Resistant to weak acids. Degradation by strong acids & bases in high concentrations or temperatures. ResistantFairDegrades in Chlorine bleach.Excellent
Technora®Resistant to mineral and organic acids. Degrades in hydochloric, hydrobromic and sulphuric acids.ResistantResistant Resistant to sea water and steam. Sensitive to bleaching and sunlight.Excellent
UHMwPEChemically inert except for strong oxidising acids.ResistantResistant to cold alcohols, ethers, esters, ketones & bleaches.High Excellent

* for properly stored rope

Rope Abrasion Resistance & Heat Reaction

FibreSurface abrasionInternal abrasionHeat reaction
SisalFairGoodBurns as fire touches flame. Supports combustion.
ManilaGoodGoodCritical temp is 150°C after which fibre burns at flame. Supports combustion.
PolyethyleneFairGoodSoftens 100°C. Melts 110°C - 120°C.
PolypropyleneGoodGoodShrinks rapidly from flame. Curls and melts at 165°C.
HT PolyesterExcellentExcellentSoftens 228°C. Melts 255°C. 
NylonVery GoodExcellentSoftens 229°C. Melts 249°C - 260°C.
Aramid (Kevlar®)FairGood371°C decomposition
Technora®Very GoodVery Good500°C+ decomposition
UHMwPEExcellentExcellentMelts 152°C.