Dyneema is an ultra-high molecular weight polyethylene fiber, and Dyneema is a type of cordage used for many different task. Dyneema is very strong, and Dyneema has a strength that is comparable to steel cables. However, Dyneema is much more lighter than steel cable because Dyneema has very few weight.
You can use the provided chart to select the correct diameter of Dyneema for your specific task, because the chart show the breaking strength of Dyneema at various diameters. The strength of Dyneema come from the molecular structure of the polyethylene fiber, and the molecular structure of the polyethylene fiber allow the Dyneema fibers to align in a way that create high tensile strength. Dyneema has very low elongation, and the elongation of Dyneema is less than three percent at the point of breaking.
Dyneema Rope: Strength, Uses and Safety
Because the elongation of Dyneema is so low, you can achieve precise control when you are pulling or haul gear. Additionally, Dyneema does not absorb water, and because Dyneema does not absorb water, the Dyneema fiber will not swell or weaken when the Dyneema fiber become wet. The strength of Dyneema increases as the diameter of the Dyneema increase, and the strength increases roughly by the square of the diameter.
For example, if you double the diameter of the Dyneema, the strength of the Dyneema will quadruple. You can use thin Dyneema for light tasks like lashing firewood, but you should use thick Dyneema for heavy task like winching a vehicle. Safety is important when you use Dyneema, and you must always consider a safety margin when you calculate the working load limit for Dyneema.
You should not use Dyneema at it’s minimum breaking load, because sudden jerk can multiply the force applied to the Dyneema. You should divide the breaking strength of the Dyneema by a factor of five or ten to find the working load limit. For example, off-road recovery may require a safety factor of five, but overhead lifting require a safety factor of ten.
You must also inspect the Dyneema for abrasion or damage before you use the Dyneema, because abrasion can make the Dyneema vulnerable to break. Dyneema has different properties then other materials, such as nylon, polyester, polypropylene, Kevlar, and steel. Nylon is good for shock absorption, but nylon absorb water and loses strength when nylon is wet.
Polyester has low stretch and is resistant to UV rays, but polyester does not float like Dyneema. Polypropylene is inexpensive and float, but polypropylene fade in the sun. Kevlar is strong, but Kevlar is heavier than Dyneema and Kevlar becomes stiff when you tie knot in Kevlar.
Steel is very strong, but steel is heavy and steel can rust. Dyneema is lighter than these material, and Dyneema floats on water. Many people use Dyneema in various industry.
Sailors use Dyneema for sheets and halyards because Dyneema is light. Climbers use Dyneema for slings because Dyneema has low stretch. Arborists use Dyneema for throwlines and rigging, and off-roaders use Dyneema for winch cable because Dyneema is safer than steel cables.
You must use splice instead of knots when you terminate the ends of Dyneema. Dyneema has a very slick surface, and the slick surface of Dyneema make knots difficult to hold. If you tie a standard knot in Dyneema, the knot can reduce the strength of the Dyneema by half.
However, if you use a Brummel splice or a Flemish eye splice, the Dyneema will retain nearly all of it’s original strength. You should practice make a splice on a piece of scrap Dyneema so that you can make a proper splice during a task. Dyneema is more expensive than many other type of rope, but Dyneema last longer than many other types of rope.
Dyneema provide low stretch, and low stretch provides you with better control. You should look at the strength chart, you should calculate your safety margin, and you should choose the diameter of Dyneema that match your specific task.
