WHAT IS DYNEEMA® ?
Dyneema® is a premium brand of ultra-high-molecular-weight polyethylene (UHMWPE), known as the world’s strongest fiber™. It’s 15 times stronger than steel, yet light enough to float on water.
After decades of fiber innovation, Dyneema® is now the sailing market’s elite ingredient material for high-performance lines and applications. For Marlow, Dyneema® is an ingredient material in many of our highest performance ropes and is used across our range from kite lines to heavy lift slings.
High Strength: On a weight for weight basis, Dyneema® is 15 times stronger than steel wire.
Light Weight: Size for size, a rope made with Dyneema® is 8 times lighter than steel wire rope.
Water resistant: Dyneema® is hydrophobic and does not absorb water, meaning it remains light when working in wet conditions.
It Floats: Dyneema® has a Specific Gravity of 0.97 which means it floats in water (specific gravity is a measure of density. Water has an SG of 1, so anything with SG<1 will float and an SG>1 means it will sink)
Chemical resistance: Dyneema® is chemically inert, and performs well in dry, wet, salty and humid conditions, as well as other situations where chemicals are present.
UV Resistant: Dyneema® has very good resistance to photo degradation, maintaining its performance when exposed to UV light
How Marlow uses Dyneema®
At Marlow, we manufacture high performance Dyneema® ropes for everybody – from the world’s top Grand Prix Racing teams to dedicated club racers. We also manufacture performance ropes with Dyneema® for kitesurfing and windsurfing.
Dyneema® was originally used to provide strength in the core of sailing lines. But today, at Marlow, Dyneema® is woven into the very fabric of modern sailing – replacing outdated metal hardware, unlocking weight savings, and improving various other applications.
With average strengths some 130%* higher than polyester ropes, when conditions get tough, Marlow’s ropes with Dyneema® give you peace of mind, knowing that they won’t let you down.
Marlow’s ropes with Dyneema® are up to 28%* lighter than regular polyester ropes, making them easier and safer to handle. Marlow ropes made with Dyneema® absorb significantly less water – meaning that they remain easy to handle even when wet.
At 30% of break load, polyester halyards can stretch by 8%, affecting the set of the sail and handling of the boat. Marlow’s halyards with Dyneema® eliminate this worry, allowing you to concentrate on enjoying yourself!
* figures for 10mm diameter ropes
Dyneema® demonstrates outstanding performance characteristics, cementing its place as the premium ingredient material inside high performance sailing applications at Marlow. Here’s why:
- Outstanding strength-to-weight ratio
- High modulus and low stretch
- Creep resistance
- Fatigue and abrasion resistance
- UV, moisture, and chemical resistance
- Smooth surface friction and handling
- Less recoil and linear stretch
- High quality and consistency
Marlow’s Innovation
Aviant Dyneema® continues to pioneer developments with the Dyneema® fibre At Marlow we have taken the performance of these Dyneema® fibres to the absolute limit by developing our “D12 Max” range of products using Dyneema® SK78 and SK99. Marlow’s “Max” process produces approximately 35% additional strength over an equivalent diameter standard rope with Dyneema®, making our “Max” products our strongest ropes yet.
Visit our Grand Prix Series section for more information about D12 Max and our innovative performance racing system.
Marlow are at the Forefront of Innovation
The use of Dyneema® is not confined only to sailors. Commercial ropes with Dyneema® are replacing steel wire in many varied applications. At Marlow, we are at the forefront of the Dyneema® revolution.
Chief among these new applications is wire rope replacement on winches. Originally championed in the recreational 4×4 market, Marlow is now pioneering the use of Winch Lines with Dyneema® in the roadside recovery market and other industrial winching applications. The benefits of replacing steel wire with Marlow’s Dynaline winch lines with Dyneema® are as compelling as they are for sailing.
Light weight: Winch ropes made with Dyneema® match steel wire for strength but offer significant improvements in terms of weight and ease of handling.
Unaffected by Water: An obvious benefit is the lack of corrosion that a winch rope made with Dyneema® exhibits. In addition, for offshore winching, the rope remains buoyancy neutal meaning that the winch only needs to lift the load, not the rope.
Unkinkable: Unlike steel wire, Dynaline will not kink and loose strength. In addition, steel wire will crush and loose strength if overlapped on a winch drum. Winch ropes made with Dyneema® will not loose strength when overlapped, crushed or kinked.
No splinters: Handling steel wire often results in wire splinters – no such issues with winch ropes made with Dyneema®.
No recoil: In the unlikely event of a ropes made with Dyneema® breaking, there is virtually no recoil, unlike steel wire where recoil is extremely dangerous.
Extensive trials have also found that Marlow’s D12 winch lines with Dyneema® need to be replaced less frequently than steel wire. The ease of handling, increased safety and improved longevity of Dyneema and HMPE winch lines are why more and more industries are making the switch.
For more information about Marlow’s winch lines with Dyneema® – visit our Vehicle Recovery section
For other products and applications using Dyneema® visit the following sections and look for the Dyneema® logo Event Rigging, Commercial & Utility, Defence – Personnel Insertion / Extraction, Defence – Towing / Recovery
The demands on high performance running rigging are becoming higher and Marlow’s Grand Prix Series offers core options using Dyneema®, Vectran, and Zylon (PBO). Each has it’s own strengths and weaknesses, but Dyneema® has become the “Gold Standard” for performance running rigging.
Dyneema® is a UHMPE (Ultra High Modulus Polyethylene, also known as UHMWPE or Ultra High Molecular Weight Polyethylene) and is available in a number of different grades. All grades of Dyneema® have excellent fatigue resistance (cyclic bending) and UV, chemical and abrasion resistance, but all have poor heat resistance due to a relatively low melting point (140○C). Dyneema® offers by far the best strength to weight ratio of any material used in rope manufacture and is the material of choice for high performance cores. Marlow offer a range of Dyneema® cores to suit application preferences as well as budget. However, with new grades of Dyneema® being introduced and different treatments available, the decision as to which core is best can often be confusing.
PRE-STRETCHING
Every Marlow D12 Dyneema® core is pre-stretched to reduce “bedding-in” elongation, limit the amount of elastic elongation and improve rope strength. Pre-stretching involves the application of heat during the process and is sometimes known as heat-setting, although simply applying heat does not have the same effect.
Marlow have been pre-stretching Dyneema® cores for over 25 years and that experience means we know exactly how to improve a rope’s performance without compromising flexibility or damaging the fibre. Marlow’s MAX Technology takes pre-stretching to a new level by using a precisely controlled process to take Dyneema® to the limits of heat and load during the Pre-Stretching process – it could be called “Super Pre-Stretching”.
D12 MAX ropes were introduced to offer the ultimate in strength realisation from Dyneema® and to virtually eliminate elastic and “bedding-in” elongation. D12 MAX ropes are stronger size for size than standard D12 – the MAX process packs more Dyneema® into the same diameter, hence the extra strength. However, D12 MAX ropes are stiffer and harder than the standard pre-stretched D12 ropes.
ELONGATION
The graphs show the relative elongation of Dyneema® SK78 and SK99 to Vectran and Zylon (PBO). When elongation is measured as a % of break load (fig. 1), it is shown that whilst PBO offers the lowest elongation followed by Dyneema® in D12 MAX and then D12, there is no differential between SK78 and SK99. However, when elongation is measured at a given load (for example 4,000kg), which is more relevant to specifying rope for on board applications (fig.2), the advantages of SK99 over SK78 in terms of elongation are clear. This is because the rope is working at a lower percentage of its break load.
CREEP
Dyneema® exhibits creep, and is important to understand how this affects a rope’s elongation characteristics. Creep can often have a negative effect on a rope’s performance and strength, when ropes are subjected to high loads for extended periods. The extension over time graph (Fig. 3) shows how Dyneema® ropes behave over a period of time.
- Initial loading will result in elastic extension. This is immediate upon loading and is immediately recoverable upon release of the load (elastic contraction)
- After the elastic extension of the initial loading, the rope will experience what is known as viscoelastic extension. This is further extension over time and is fairly limited. Unlike elastic stretch, the viscoelastic stretch will only recover slowly over time once the load is released.
- Finally there is creep, which is permanent, non-recoverable and time-dependent. Creep occurs at the yarn molecular level when the rope is under constant load.
- Once the load is released and elastic and viscoelastic extension recovered, the rope will ultimately have experienced an element of permanent extension. This is a factor of both creep and “bedding in”, which is when individual fibre components in the rope and/or splice settle into their preferred position when under load.
Marlow leads the market performance yachting rope technology. Our Grand Prix Series offer performance benefits and a competitive edge… and is specified by winners!
Marlow Ropes are proud to be using Dyneema®
With its excellent durability, Marlow uses Dyneema® to produce longer-lasting ropes so our customers need to replace their lines less often. The result is less material use, less waste, and a lower environmental impact over time.
Dyneema® fibre’s superior tenacity means you need less of it to achieve an exceptionally high level of strength. This means Dyneema® delivers the lowest carbon footprint per unit of strength compared to alternative materials such as polyester, nylon, cotton, hemp, or generic HMPE.
Bio-based Dyneema® is ISCC certified as sustainable and renewable via “mass-balancing”. This means that the Ethylene feedstock used to make Dyneema® is transitioned from conventional petrochemical sources to sustainable and renewable sources with no change to the manufacturing process or the quality and performance of the yarn.
Bio-Based Dyneema products
Bio-based Dyneema® has identical technical characteristics and performance as conventional Dyneema® but uses waste from the pulp and timber industry as its primary raw material.
Bio-based Dyneema® is ISCC certified, as sustainable and renewable via “mass-balancing”. This means that the Ethylene feedstock used to make Dyneema® is transitioned from conventional petrochemical sources to sustainable and renewable sources with no change to the manufacturing process or the quality and performance of the yarn! Therefore, any rope made with Bio-based Dyneema® by Marlow directly contributes to reduced CO2 emissions and has a lower environmental impact.
Therefore, any rope made with Bio-based Dyneema® by Marlow, directly contributes to reduced CO2 emissions and has a lower environmental impact.
Every tonne of Bio-based Dyneema® we use reduces carbon emissions by 5 tonnes compared with a tonne of conventional Dyneema®••. The comparison with generic HMPE is even starker – 1 tonne of Bio-based Dyneema® produces 29 tonnes less CO2 than 1 tonne of generic HMPE*. That is equivalent to charging 3.7m Smart phones or the same CO2 offset by 480 seedling over 10 years.
Photo reference: Aviant
** calculated by Aviant Internal Life-Cycle Assessment
As part of Marlow’s BLUE OCEAN® sustainability mission we introduced Bio-based Dyneema® fibre into our Leisure Marine rope range at the start of 2020.
English (US)
Español
Italiano