In 1953 EDELRID invented the kernmantel rope and consequently revolutionized climbing. The kernmantel rope set the standard for modern climbing ropes. Up until then, ropes were generally hawser laid (twisted) or braided constructions made of hemp or basic nylon. However, only kernmantel ropes are able to meet the requirements of ambitious alpinists and climbers. They are lightweight, strong and have high safety reserves.
The kernmantel construction we invented has two-parts: a core (Kern) and a protective sheath (Mantel). The core is a rope’s main load-bearing element. The sheath is braided around the core to protect it from external influences. In order to use a rope correctly, it’s important to understand what a kernmantel rope is made of and how it’s manufactured. A rope has to pass through many stages before the finished product is ready for use.
Fig.1: Raw Material
The basic raw material used to make all climbing ropes are ultra-thin filaments made of high-quality polyamide 6 (nylon). They are used to make both the core and the sheath. We would like to show the journey that each individual ultra-thin filament undertakes before it becomes a rope. In keeping with the kernmantel concept, we have broken the manufacturing process down into different stages for the core and the sheath.
Fig.2: Rope Core
Up to 135 of the ultra-fine polyamide filaments are twisted together to make a strong yarn. A number of these yarns are then combined (twisted) in a multistage process to make a core strand. The process is called twisting. It’s this twisting process for the strands in the core that gives the rope its dynamic elongation, i.e. the ability to act like a spring when shock loaded. The number of twists over a given length determine the mechanical elongation and strength of a rope. A rope may contain up to 2,000 meters of these core strands.
Next comes an important manufacturing stage. As nylon is only supple up to a point, the yarns are subjected to a sophisticated industrial treatment. In an autoclave, a kind of gigantic pressure cooker, the fibres are shrunk together using a special combination of heat, pressure and time. The rope is now starting to take shape. It has its main dynamic characteristics. The core is ready for use. Meanwhile, the sheath yarns are prepared simultaneously.
Fig.4: Rope Sheath
The same principle is used to make the sheath as the core strands. Two to four colored twisted yarns are combined (twisted together) and wound onto spools. To ensure that the sheath yarns have the same characteristics as the core strands, they too are placed in the autoclave to shrink. To guarantee that the sheath strands are uniformly conditioned in the autoclave, they first have to be unravelled. This is done using a special machine that unravels the strands into loosely coiled lengths, or skeins. Once these skeins have been autoclaved, they are unravelled again and then spun back onto the spools ready for the next step.
The next step produces the finished rope. The sheath and the core are now ready to be combined (braided). A braiding machine twists the sheath strands around the required number of core strands, depending on the type of rope being produced. The bobbins with the sheath yarns dance around the core strands at high speed – rather like dancing around the maypole . After more than a thousand meters of braiding, the bobbins are empty and the rope is ready. During this braiding process we deploy a number of innovative techniques: Our standard sheath construction, i.e. the way that EDELRID sheath yarns are braided together, is called a single-braid tandem . This tried-and-tested construction braids two yarns over two other yarns.
EDELRID Sports Braid sheath braiding is different to the standard sheath construction in that two yarns are braided over one other yarn. The result is a very compact and smooth sheath structure. It’s this construction method that gives EDELRID Sports Braid ropes their outstanding suppleness and exceptional abrasion resistance. The Sports Braid sheath construction is ideal for ropes that are subjected to prolonged wear and abrasion, e.g. top-roping and intensive sport climbing.
An innovative braiding process for making bicolor ropes. The woven design of the rope completely changes when it reaches the middle. This provides a permanent and distinctive middle marking. We use this technique exclusively for the ropes in our Pro Line. During braiding, the bobbin order of the sheath yarns alters on the braiding machine automatically at the middle of the rope. The design then changes so that two rope halves of the rope are easy to distinguish.
An innovative and patented EDELRID process to manufacture bicolour ropes. The braiding spools are changed halfway through the braiding process to add a bicolour strand into the sheath so that each half of the rope has a different pattern. The DuoTec process provides permanent marking, so the differently-patterned rope halves are easily identifiable. This is very useful when abseiling or determining how much rope you have left and when butterfly coiling.
TouchTec is an EDELRID sheath braiding process (patent pending). It produces different performance characteristics that can be felt as well as seen. TouchTec technology is applied to a section at each end of the rope. The first and last five meters have a distinctive marking and are tactilely different to the rest of the rope. This means that the belayer automatically sees and feels the end of the rope approaching when lowering their partner. TouchTec reduces the risk of accidents when lowering and also facilitates rope management. The different sheath structure is produced by weaving a strand that has a slightly textured surface and a distinctive colour into the sheath at the last five meters of both ends.
LinkTec technology involves bonding the sheath and the core of the rope together during braiding. This reduces sheath slippage to a minimum and significantly prolongs the lifespan of a rope. We’ve been using this process for our ropes for climbing walls for a long time, as they have to withstand prolonged wear and abrasion during top-roping.
The exact details of our various finishing treatments are some of the most closely-guarded secrets in the mountain sports industry. These treatments give a rope specific properties that extend its lifespan, improve handling and prevent it from absorbing water. All our ropes receive a finishing treatment. The top-of the range Pro Line models get the full works, i.e. Pro Shield, Dry Shield and Thermo Shield. Our Sports Line ropes are given a Thermo Shield treatment, which gives them their characteristic EDELRID handling and flexibility. All of our finishing treatments are bluesign® certified and use only strictly-regulated, environmentally-friendly processes that contain no harmful substances.
Untreated ropes can absorb up to 50 % of their own weight in water. When wet, such ropes become extremely heavy, difficult to handle and may freeze in cold conditions. Moreover, their safety reserves are compromised. This is why impregnated ropes are used for activities where ropes are more likely to get wet, such as ice climbing or mountaineering.
Thermo Shield is the standard finishing treatment that we apply to all our ropes to give them the famous EDELRID feel and handling characteristics. This thermal stabilizing process ensures that the core and sheath yarns are perfectly balanced. A special heat treatment first relaxes then shrinks the rope’s fibres. This harmonizes the individual yarns inside the rope and ensures that it remains compact and supple throughout its life. The result is a rope that does not shrink or quickly become stiff. Ropes that do not undergo a thermal stabilizing process often shrink and dry out more quickly. They tend to be stiffer than ropes that have been heat-treated.
Our Pro Shield finish increases a ropes ability to withstand external forces (falls). During the finishing process every single core and sheath yarn is covered with a Teflon coating. The microscopic Teflon particles are bonded to each individual fibre. This gives the rope a protective coating that substantially improves its loading characteristics. In addition, the Pro Shield finish also provides increased dirt and water resistance. We use the Pro Shield finish exclusively for our for Pro Line ropes.
Fig.5: Quality control and packaging of the ropes
Quality Control and Packaging
Once a length of rope has received its respective treatments, it’s off to the finishing department. The finishing department is a rope’s last stop before it leaves our production facilities. During a final inspection, every single meter of the rope is checked by hand. Our employees are so experienced that they can detect even the slightest irregularities. Over the years they’ve developed an extraordinary feel that represents an important additional quality control measure for our ropes. Once a batch has passed this final inspection, it’s cut into the required lengths. A further machine sees to the middle marking. The rope ends are then sealed. The finished rope is coiled on a coiling machine, weighed and packed with its label and instructions for use. The rope is ready to be sent out.