Page 59 - 2015_LEF-eCatalog

Understanding Ropes vs Environment
GENERAL EFFECTS of WATER or ELEVATED
HUMIDITY on NYLON* Nylons absorb a significant amount of water/moisture, whether by immersion or, perhaps surprisingly, by simple exposure to elevated humidity for even a relatively short period of time. Once moisture enters these fibers, they never return to 100% strength or original quality. Below are some mechanical and physical properties that are negatively affected by moisture.
NEGATIVE EFFECTS of MOISTURE on many FIBERS
The chart below illustrates the various strengths and weaknesses
of available rope fibers. Note that the properties highlighted in blue are
testing results with water/moisture taken into consideration. Current testing protocols are all
conducted in a laboratory environment with controlled humidity and temperature. Understanding the environments
that you work in, we believe that water/moisture
is a major factor that needs to be considered.
Unfortunately, operational conditions are not predictable or controllable. Pegasus Ropes® use NFPA/UIAA testing standards in
addition to tests conducted under full humidified/wet conditions.
Strength Loss (up to 70%) Dynamic Performance Fall Arrest Peak Force Knotability
Melting Point
Abrasion Properties Elongation
Weight Gain (6%-9%) Sheath Slippage Diameter
Rope Fiber Characteristics
PROPERTY
Cost per lb
Specific Gravity g/cc (weight)
Breaking Tenacity gF/denier (dry) Moisture Regain
Water Resistances
Strength Retention in H2O
Elongation at Break % (dry)
Melting Point (C/F)
Abrasion Resistance (dry)
Abrasion Resistance (wet)
UV Resistance
Knotability
Chemical Resistance: ACID
Chemical Resistance: ALKALI
Chemical Resistance: ORGANIC SOLVENT
InnegraTMS
Good 0.84 9.5 Excellent Excellent Excellent 9.5 162/324 Good Good Good Excellent Excellent Excellent Excellent
Polypropylene Polyester
Excellent Excellent 0.91 1.38 3.0 9.3
Excellent Good Excellent Excellent Excellent Good
19.0 14.6 162/325 256/493 Poor Good Poor Good Poor Good Excellent Excellent Excellent Excellent
Excellent Poor Excellent Good
Nylon 6
Excellent 1.14 9.0 Poor Poor Poor 20.0 254/489 Good Poor Good Excellent Poor Good Good
Dyneema Technora
Poor Poor
0.97 1.44
38.0 23.0 Excellent Poor Excellent Poor Excellent Good
3.1 3.5 147/297 427/800 Good Excellent
Good Good Good Poor Poor Good Excellent Excellent
Excellent Good Good Good
The Rope Fiber Characteristic chart is a homogenized view of fiber characteristics. Many factors can alter performance of materials.
*Sterling Rope Company’s “Guide to Rope Engineering, Design and Use, (Flory, McKenna, Parsey, 1982) (UT Knoxville (Raghavendra R. Hegde, Atul Dahiya, M. G. Kamath (Monika Kannadaguli and Ramaiah Kotra April, 2004) “AMILAN* Nylon Resin.” Mechanical Properties | AMILAN* | Plastics Products | TORAY. Toray Industries Inc., n.d. Web. 08 Oct. 2013.
Note: Para-Aramid (Kevlar, Nomex, Technora) are hydrophilic (water absorbing) have the same general properties when moisture enters the fiber.
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