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 | |