Fibre Qualities

Description

Fibre Qualities

Comparative Characteristics

Fibre Tenacity of dry fibre (gm/denier) Wet strength compared to dry strength Rope shock load absorption Specific Gravity Able to float Strength/ Weight ratio (av.) Elongation & Creep
Sisal 4-5 Up to 120% Poor 1.5 No Fibre elongation: Dry 2.9%, Wet 3.4%.
Rope elongation: Dry 13%, Wet 16%.
Extension causes rupture.
Manila 5-6 Up to 120% Poor 1.5 No Fibre elongation: Dry 2.8%, Wet 3.2%.
Rope elongation: Dry 13%, Wet 15%.
Extension causes rupture.
Polyethylene 6 100% Good 0.95 Yes 2.10 High tenacity. Good recovery after stretch and extension at break of 50%. High creep.
Polypropylene 6.5 100% Very Good 0.91 Yes 2.50 High tenacity. Good recovery from stretch and elongation at break for ropes is 25-30%. High creep.
HT Polyester 7-10 100% Very Good 1.38 No 2.25 Elongation 35% at break. Low creep.
Nylon 9 85-90% Excellent 1.14 No 3.00 Elongation Dry 40%. Wet 35%.
Moderate creep.
Aramid (Kevlar®) 18-26 95% Fair 1.44 No Elongation 4% at break. Very low creep.
Technora® 28 100% 1.39 No Elongation 4.5% at break. Low creep.
UHMwPE 28 100% 0.97 Yes Elongation 2-5% at break.

 

Chemical Resistance & Degradation

Fibre Effects of acids Effects of Alkalis Effect of Organic Solvents UV resistance in sunlight Other Resistance to aging*
Sisal Degradation of acids in high concentration or temperature. Resistant Resistant Good Degradation by sea water, paints, detergents, chemical salts and fats Good
Manila Degradation of acids in high concentration or temperature. Degradation by alkalis. Resistant Good Degradation by paints, detergents, chemical salts and fats Good
Polyethylene Very resistant Very resistant Soluble in hot chlorinated hydrocarbons. Good (UV stabilised) Excellent
Polypropylene Very resistant Very resistant Soluble in chlorinated hydrocarbons. Good (UV stabilised) Excellent
HT Polyester Resistant 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
Nylon Decomposed by strong mineral acids. Resistant to weak acids. Little or none Resistant, 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. Resistant Fair Degrades in Chlorine bleach. Excellent
Technora® Resistant to mineral and organic acids. Degrades in hydochloric, hydrobromic and sulphuric acids. Resistant Resistant Resistant to sea water and steam. Sensitive to bleaching and sunlight. Excellent
UHMwPE Chemically inert except for strong oxidising acids. Resistant Resistant to cold alcohols, ethers, esters, ketones & bleaches. High Excellent

* for properly stored rope

Rope Abrasion Resistance & Heat Reaction

Fibre Surface abrasion Internal abrasion Heat reaction
Sisal Fair Good Burns as fire touches flame. Supports combustion.
Manila Good Good Critical temp is 150°C after which fibre burns at flame. Supports combustion.
Polyethylene Fair Good Softens 100°C. Melts 110°C – 120°C.
Polypropylene Good Good Shrinks rapidly from flame. Curls and melts at 165°C.
HT Polyester Excellent Excellent Softens 228°C. Melts 255°C.
Nylon Very Good Excellent Softens 229°C. Melts 249°C – 260°C.
Aramid (Kevlar®) Fair Good 371°C decomposition
Technora® Very Good Very Good 500°C+ decomposition
UHMwPE Excellent Excellent Melts 152°C.