Characteristics of Fibres
Comparative Charactersistics of various Fibres |
|
Nylon |
Polyester |
Polyrene |
PP/Polysteel |
Polythylene |
Cotton |
Strength |
|
|
|
|
|
|
Tenacity of dry fibre (in grams/denier) |
9.0 |
8.5 |
7.5 |
7.2 |
5 - 6.0 |
2 - 3.0 |
Wet strength compared to dry strength |
85 - 90% |
100% |
100% |
100% |
100% |
up to 120% |
Rope shock load absortion ability |
Excellent |
Good |
Very Good |
Very Good |
Very Good |
Very Poor |
Weight |
|
|
|
|
|
|
Specific gravity of fibres or filaments |
1.14 |
1.38 |
1.14 |
0.91 |
0.95 |
1.54 |
Able to float |
No |
No |
No |
Yes |
Yes |
No |
Rope Strength/wgt.ratio (average) |
3,0 |
2,25 |
2,5 |
2,5 |
2,1 |
0,50 |
Elongation |
|
|
|
|
|
|
Typical per cent of rope elongation @ Break |
20-30% |
12-18% |
12-18% |
18-22% |
20-25% |
10% |
Creep (extention under sustained load) |
Moderate |
Low |
Low |
High |
High |
Low |
Chemical Resistance |
|
Nylon |
Polyester |
Polyrene |
PP/Polysteel |
Polythylene |
Cotton |
Effects of Acids |
Decomposed by strong mineral acids: resistant to weak acids |
Resistant to most mineral acids: disintegrated by 95% sulphuric acid |
Resistant to most mineral acids: disintegrated by 95% sulphuric acid |
Very Resistant |
Very Resistant |
Will Disinte-grate in hot diluted and cold concentrated acids |
Effects of Alkalies |
Little or none |
No effect cold: slowly disintegrated by strong alkalies at the boil |
Very Resistant |
Very Resistant |
Very Resistant |
Will lose strength where exposed |
Effect of Organic Solvents |
Resistant, soluble in some phenolic comp-ounds and in 90% formic acid |
Generally unaffected. Soluble in some phenolic compounds |
Generally unaffected. Soluble in some phenolic comp-ounds |
Soluble in chlorinated hydrocarbons |
Soluble in hot chlorinated hydrocarbons |
Good Resistance |
Degredation |
|
Nylon |
Polyester |
Polyrene |
PP/Polysteel |
Polythylene |
Cotton |
Resistance to ultraviolet in sunlight |
Good |
Good |
Good |
Good (UV-Stabalised) |
Good (UV-Stabalised) |
Good |
Resistance to ageing for properly stored rope |
Excellent |
Excellent |
Excellent |
Excellent |
Excellent |
Good |
Rope Abrasion Resistance |
|
Nylon |
Polyester |
Polyrene |
PP/Polysteel |
Polythylene |
Cotton |
Surface |
Very Good |
Best |
Very Good |
Good |
Fair |
Good |
Internal |
Excellent |
Best |
Excellent |
Good |
Good |
Good |
Effect of Temperature on Dry Rope |
|
Nylon |
Polyester |
Polyrene |
PP/Polysteel |
Polythylene |
Cotton |
High temperature working limit |
149'C |
149'C |
130'C |
93,2'C |
80'C |
149'C |
Low temperature working limit |
-21'C |
-21'C |
-26'C |
-26,7'C |
-50'C |
-37,8'C |
Melts at |
249'C |
250'C |
180'C |
164'C |
130'C |
|