Additional Information Affecting Selection and Use of Cortland Rope Slings
Plasma® HMPE fiber rope slings are very durable and resistant to most environmental damage.
Environmental Effects Which Could Affect Plasma® 12x12 Rope Slings
The following information is provided to support the decision to use these slings in heavy lift applications. Additional information is available; please see the Plasma® 12x12 Inspection/Repair Guidelines for additional information and how to inspect for suck heat damage and other forces.
Plasma® 12x12 Rope Properties
Temperature
Heat
As mentioned above, Plasma is an HMPE fiber. This type of fiber gradually begins to lose strength above approximately 65 C /150 F (the critical temperature) and melts at 150 C/297 F. The MBL at elevated temperatures under sustained loading could be reduced depending on time, temperature and the percentage of load applied. Long term exposure above 55 C /140 F is not recommended.
Users of Plasma rope slings need to be aware of high ambient, reflected heat or friction heat in applications, as well as proximity to localized heat sources such as open flames or welding that could damage the sling. If it is anticipated that heat will be an issue in the use of Plasma lifting sling, care should be taken to protect the rope from heat through the use of chafing gear. Slings with temperature damage include melting, fused or brittle strands and significantly reduced diameter. Note- fused strands should not be confused with strands that have been tightly compacted and stiffened due to high loads. For additional information see the inspection and repair guidelines. If high temperatures are unavoidable, an alternative high modulus synthetic fiber may be desirable; e.g. aramid fiber or liquid crystal polymer (LCP), which has a significantly higher critical temperature rating. Cortland offers torque-free 12x12 constructions of higher heat resistant braided slings such as Vectran(LCP) and Technora (Aramid).
Cold
Plasma® HMPE fiber ropes exhibit zero loss of strength in cold environments tested down to -150 C/-200 F. In fact, Plasma® ropes gain strength in extreme cold temperatures.
Chemical Exposure
The Plasma HPME fiber is impervious to most common chemicals. However, these rope slings can lose strength and fiber structural integrity when exposed to highly acidic chemicals (please see chart below).
Plasma® fiber chemical resistance
Strength Retention after Chemical Immersion
Effects of Sunlight and Ultraviolet Light
Plasma® HMPE fibers have very good resistance to extended exposure to the sun (UV). When compounded into yarns, strands and rope constructions, the increased density and compaction of the fibers in the rope structure offers UV resistance superior to almost all other high modulus synthetic fiber ropes including nylon, polyester, aramid, LCP, PBO and others. Prolonged exposure to sun and UV may eventually damage the outside filaments of a rope, causing some broken fibers. However, both the water-based urethane coating and storage under cover can mitigate potential UV damage.
