The world’s most creep-resistant ultra-high molecular weight polyethylene fiber is even better than previously thought. Producer DSM Dyneema unveiled DM20, based on its new Dyneema® Max Technology, at the OTC Offshore Technology Conference in 2012, for use in mooring ropes for offshore production platforms.
Since then, the company has been carrying out extensive characterization studies on the lifetime and tensile properties of this ground-breaking fiber. DM20 is fully commercial, with a set of final specifications that exceed the data presented at OTC 2012.
Dyneema® Max Technology is an innovative platform technology that will extend the use of Dyneema®, which was already the world’s strongest fiber. DM20 is designed for long-term permanently loaded systems, such as mooring offshore production platforms. Mooring ropes made with DM20 outperform all alternatives, surpass industry standards for deep water permanent moorings, and will outlast the operational life of the installation.
The new technology also opens the door for applications outside of the scope of offshore permanent mooring where designers need the excellent dynamic properties of high modulus polyethylene (HMPE) fiber for high-strength tension members that are under permanent load. “DSM Dyneema is supporting potential customers in the development of totally new applications for Dyneema® Max Technology in such areas as industrial and renewable energy,” says Jorn Boesten, Segment Manager Offshore at DSM Dyneema. “In addition, we are working on further developments based on the Dyneema® Max Technology platform.”
One major existing customer, Lankhorst Ropes, has already used DM20 to produce a special version of its Gama 98 mooring rope. Working with a 34-mm subrope produced by Lankhorst, DSM Dyneema has been carrying out endurance tests according to ISO/TS norm 14909 at Norwegian classification society DNV GL’s facilities. These involve subjecting the rope to 10,000 cycles of between 5 and 50% of break load stress. The rope passed the tests without problem. Lankhorst also verified the creep characteristics of its Gama 98 rope with DM20.
In addition, DSM Dyneema has been building up a broad database. This confirms that the behavior of DM20 is just as good as the company’s existing class-leading fibers, Dyneema® SK75 and SK78. Furthermore, it has also proven its capability to produce DM20 consistently on an industrial scale.
“Our data show that in normal operating conditions, below 40°C and below 20% of break strength, the creep of the fiber is almost non-existent. In 2012, we predicted creep of 0.2%, and the new test data show it is below that,” says Boesten.
With DM20, Dyneema® has taken a major step forward in the development of fibers with extremely low creep, Boesten adds. “No other HMPE fiber comes even close to these creep properties, and we are confident that no other failure mode dominates over creep in DM20. Just as important, we are now capable of producing the fiber with a consistent high quality in our commercial facilities.”