Dyneema Rope, Dyneema Cord, Dyneema Line (braided)

• Material: HMPE (High-Modulus Polyethylene), UHMW-PE (Ultra High Molecular Weight Polyethylene)
• Brand name: Dyneema®
• Manufacturer: DSM (Koninklijke DSM N.V.)
• Currently relevant fiber types: SK 38, SK 75, SK 78, SK 99, DM 20
• Yarn strength: 28 - 40 cN / dtex
• Specific weight: 0.97 kg / dm³
• Water absorption: 0 % (hydrophobic)
• Strength loss due to moisture: 0 %
• Knot strength: 35 % - 50 %
• Light resistance / UV resistance: good
• Elongation at break: 3.8 %
• Abrasion resistance: good
• Washing temperature: 30 °C
• Acids (50% concentration): no effect
• Gasoline, diesel, lubricating oil: no effect
• Solvents: minor effect
• Alkalis (bases): resistant
• Electrical properties: excellent electrical insulation capacity
• Temperature limit (short-term load): approx. 70 °C
• Softening temperature: approx. 120 °C
• Melting temperature: approx. 150 °C

While the properties mentioned above generally apply to all types of Dyneema® fibers, there are specific differences that can be found in the following overview:

Dyneema® is the trademarked brand name for certain HMPE fibers that are exclusively produced by the Dutch chemical company DSM. HMPE stands for High Modulus Polyethylene. "Modulus" refers to Young's modulus of elasticity (commonly known as the "E-modulus"), which is a measure of a material's ability to deform. The high modulus of these specific polyethylenes means that this material is extremely tear-resistant and has high tensile strength.

While HMPE refers to the entire class of high-strength polyethylenes, Dyneema® represents a smaller group within it, specifically the HMPE fibers manufactured by DSM. The HMPE fiber was discovered and developed to market maturity by researchers employed at DSM. The difference between Dyneema® and other HMPE fibers also lies in this technological advantage. Since the 1990s, DSM has continuously improved its manufacturing processes and products. Dyneema® stands for advanced materials with highly advantageous properties for the production of genuine high-performance ropes.

UHMW-PE is another common abbreviation for the class of HMPE fibers. UHMW stands for Ultra High Molecular Weight Polyethylene.

While the abbreviation HMPE refers to a specific property (namely the high modulus of elasticity) to describe this class of polyethylenes, the abbreviation UHMW highlights the molecular feature that causes this property: The polyethylene molecules in this class are particularly long and therefore very heavy (compared to other molecules).

UHMW-PE is simply an alternative term for HMPE fibers. And Dyneema® is the group of UHMW-PE fibers manufactured by DSM.

Dyneema® is a high-performance fiber. This means it has excellent material properties, making synthetic fiber ropes a viable option in applications where this was previously not a realistic choice. The key advantages of Dyneema® are:

1. High strength
2. Low specific weight
3. Resistance to environmental influences
4. Good splicing capability

High strength, high modulus of elasticity

The most outstanding feature of Dyneema® is its very high tensile strength combined with low weight. The specific strength of this synthetic fiber is 28 - 40 cN/dtex (depending on the type and thickness of the fiber). This makes Dyneema® about 15 times stronger than steel, whose value is around 2 cN/dtex. In other words, a Dyneema® rope can replace a steel rope and is about seven times lighter for the same breaking load.

Low specific weight

Dyneema fibers have a specific weight of about 0.97 kg/dm³. This makes them lighter than water, meaning they are buoyant. In combination with their high strength, this low weight offers a significant safety advantage if the rope were to break under load—unlike the risk posed by a heavy steel rope whipping dangerously.

Resistance to environmental influences

Dyneema® ropes have high to very high resistance to external factors:

• Abrasion resistance is good, so chafing is generally not an issue. If necessary, a core-sheath construction with a Dyneema® core and a protective polyester sheath can be used.
• Sunlight and UV radiation have little effect on a Dyneema® rope, making it suitable for continuous outdoor use
• Dyneema® fibers do not absorb water and do not lose strength when exposed to water, whether freshwater or saltwater.
• Dyneema® ropes are also resistant to most chemicals, particularly gasoline, diesel, lubricating oil, acids, alkalis, and most solvents.

Good splicing capability

Dyneema® ropes are very easy to splice. This applies equally to 100% Dyneema® braided ropes and ropes with a Dyneema® core and an outer sheath made of another material. If there is an intermediate sheath between the core and the outer sheath, it must be removed over the length of the splice. Refer to the manufacturer's splicing instructions.

Dyneema® ropes are also ideal for applications requiring endless ropes or grommets. A specially spliced Dyneema® piece is also used as a textile replacement for heavy metal shackles (known as soft shackles).

However, Dyneema® has three main disadvantages that must be considered in certain applications:

1. Low melting temperature
2. Low knot strength
3. Creep

Low melting temperature

The melting temperature of Dyneema® is around 170°C, the lowest of all synthetic fibers relevant to rope manufacturing. This makes Dyneema® unsuitable for use in high-temperature environments. The maximum temperature to which Dyneema® ropes can be exposed in the short term is around 70°C.

In applications with high ambient temperatures, aramids are the superior material, offering both high strength and high temperature resistance. Switch to the "Aramid Ropes" category.

Low knot strength

The knot strength and general knotability of pure Dyneema® ropes are below average compared to ropes made from conventional synthetics such as polyamide, polyester, or polypropylene. However, compared to ropes made from other high-strength fibers such as aramid or Vectran®, Dyneema® ropes have comparable or slightly better knot strength.

This limitation of Dyneema® can be easily compensated for:

Either use a splice instead of a knot. Braided Dyneema® ropes are very easy to splice, and a splice retains about 80% of the rope's breaking load.

Alternatively, if the rope must be knotted, a Dyneema® rope with a polyester sheath can be used. The sheath improves knotability and reduces tight bending radii, which decrease the breaking load at the knot.

Creep

Creep occurs in all synthetic fibers, but it is particularly pronounced in HMPE fibers. Creep refers to the undesirable, permanent elongation of the fiber or rope as a result of use. Eventually, creep will lead to material failure.

To determine whether Dyneema® creep may be an issue in a specific application, it is important to understand the factors influencing creep:

• Temperature: The higher the ambient temperature, the more pronounced the creep.
• Type of load: Constant high, static tensile loads promote creep, while alternating loads are better tolerated.
• Load level: The higher the load relative to the rope's breaking load, the more pronounced the creep. Creep is of minor importance at loads around 25% of the breaking load.
• Duration of use: The longer the rope is in use, the more it elongates through creep.

However, creep in Dyneema® should no longer be seen as a general disadvantage. Through further research and development, DSM has significantly improved the creep behavior of current Dyneema® fibers (SK 78 and SK 99). Moreover, a structurally different Dyneema® fiber (DM 20) has been developed where creep is no longer a concern.

High level of innovation from the manufacturer

Finally, it should be noted that the manufacturer of Dyneema®, the Dutch company DSM, continuously develops and improves the fibers. Since their market introduction in the 1980s, the positive properties have been significantly enhanced, and the disadvantages reduced. Consequently, each new generation of Dyneema® fibers is replaced by even more powerful products.

Dyneema® ropes, twines, and cordage can be used as optimal replacements for steel cables. For heavy-duty operations or in areas with extreme demands on breaking strength, weight, and stretch, Dyneema® ropes are often the better choice—especially when weight savings and handling advantages play a role in the decision:

• In leisure and outdoor activities, e.g., as winch ropes for off-road and rally vehicles, paragliding and kite lines, fishing lines, launch winch ropes at glider airfields, as halyards, sheets, and trim lines (running rigging), shrouds and stays (standing rigging) in sailing, as kite lines, or surfing straps.
• In commercial shipping as mooring lines for cargo and cruise ships.
• In industrial applications and mechanical engineering, e.g., as pull and control cables in robots, as crane ropes, or in large open-pit equipment like draglines and bucket wheel excavators.
• In forestry, as recovery ropes, choker slings, felling assistance ropes, or forestry winch ropes for timber skidding and forest work.
• In medicine (endoprosthetics): Dyneema® twines are so powerful that they are even used as part of joint prostheses.

Your desired product is not listed in our online shop? We can offer you a customised solution. In this case, we have the required rope manufactured specifically according to your requirements. The prerequisite is the purchase of at least one machine set per desired variant of the product. The delivery time for these customised orders is usually approximately two to three weeks.

We happily take care of your need for manual assembly as well. We can cut the rope to the lengths you require and provide additional ropework. Decorative knots, individual splices and whippings, special packaging and labelling can also be ordered from us. These services can be provided even in large quantities.

Please feel free to send us your enquiry now! We take the time to listen to you and answer your questions. We see each individual request of our customers as a challenge which we seek to meet. Through established partnerships with selected rope manufacturers, our many years of experience, efficiency, and flexibility, we are able to deliver on that promise.