Distrupol’s technical know-how helps revolutionise ski binding system

As a leading polymer distributor, technical service and solutions provider, Distrupol in the Nordic region has a long history of assisting customers in the winter sports industry. One of the company’s most recent contributions has been in providing support for a revolutionary ski-binding development, known as the Nordic Integrated System (NIS).

An industry ‘first’ this new all plastic system, jointly developed by ski manufacturers Madshus and Rossignol and Norwegian ski-binding producer Rottefella, makes it possible to mount the binding to a cross-country ski without the use of screws. The NIS slide and ‘click-on’ concept not only allows easier and quicker mounting, it also provides for the binding to be adjusted by the skier, to complement his or her individual kick and technique, while offering improved stability and ski control.

According to Robert Tomter, Product Development Manager at Rottefella: “An important step in realising the NIS concept was identifying the right materials for its component parts. This was particularly true for the plate, which forms the critical connection between the ski and the binding. Distrupol was the first supplier to fully grasp the complex technical requirements of the project given the combination of mechanical and chemical properties demanded. With its materials know-how and technical support capabilities, Distrupol played a crucial role in supporting Rottefella in an extensive testing and evaluation program. This ultimately resulted in an unconventional choice of material, but with the necessary properties at a competitive price.”

The NIS system comprises of a plate that is attached to the upper surface of the ski by producers Madshus and Rossignol in the final manufacturing step, making it an integral part of the ski. On top of this Rottefella’s New Nordic Norm binding slides into place and locks easily in five different positions.

“The real technical challenge was to match material to the NIS production and performance criteria,” says Jon Asle Sjöli, Polymer Engineer at Distrupol. “The plate material properties had to be close to those of the ski's top surface in order to maintain integrity and withstand the mechanical loads of skiing. It also had to resist low temperatures, snow, ice, water and exposure to UV radiation.”

He continues: “In addition to the physical and environmental stresses the material of choice had to be resistant to chemicals such as wax removers, yet be compatible with the adhesive bonding between plate and ski. This complex combination of demands led us to an extensive test program involving a number of materials and, ultimately, we came to a non-traditional material choice for this type of application - LG Chem’s ABS HI-100, which was able to satisfy all requirements.”

The selection of material for the plastic parts of the main binding was a simpler process, as the Distrupol team has substantial previous experience in supporting these applications. Delrin® 127 POM from DuPont was the material of choice, proven over many years to be very successful in ski bindings, due to its high strength at low temperatures.

“The value of Delrin was confirmed by its excellent snap-fit properties,” Jon Asle explains. “These enabled the innovative integration into the binding housing of the two locks that hold it in place on the ski. The locks fit in corresponding recesses in the NIS plate and it is this system that makes it possible to re-position or completely remove the binding from the ski.”

The Nordic Integrated System was officially launched in January 2005 but was only released commercially for the 2005/2006 winter sport season. Professional cross-country skiers have already won many ‘World Cup’ races in all categories; classic, skating, biathlon and sprint using the NIS and the system will feature on Madshus and Rossignol Nordic skis at the Torino Olympics.