From professionals to hobbyists, skiers all over the world optimize performance on the snow with composite equipment.
When you tune in to watch the 2018 Winter Olympics in PyeongChang, South Korea, you will see many athletes pushing their limits on skis made with composite materials. FRP composites made their way into skis in the second half of the 20th century and since then have become pervasive. Because the materials are commonplace in skis, it’s easy to assume there are no innovations in the mature market. However, ski manufacturers strive to improve products just like their counterparts in other industries.
According to Dodd Grande, senior vice president of engineering and product development at K2, improvements to composite skis have historically been driven by the evolving needs of different types of skiers. For instance, an alpine skier relies mostly on gravity for propulsion, whereas backcountry skiers provide propulsion themselves. As a result, no two skis are the same.
According to Grande, many of today’s alpine skis primarily feature a combination of aluminum and composites. Because there is such a wide range of dissimilar materials used to make alpine skis, choosing the right bonding material is critical. Grande says most of the industry today uses epoxy adhesives because over time, they have proven suitable for bonding nearly all substrates.
The core of many alpine skis is either wood or polyurethane, while the edges are steel. The bottom (or base) of most alpine skis features ultra-high-molecular-weight (UHMW) polyethylene. After sintering, base materials are formed in one of two ways: continuous compression molding (CCM) or scything.
Today, the company at the forefront of prepreg CFRP alpine ski production is Salt Lake City, Utah-based DPS Skis. As the company explains on its website, while many ski makers claim to make carbon fiber skis, they are actually dry carbon laminates mixed with fiberglass in a wet lay-up.
According to Alex Hunt, marketing manager at DPS, in addition to weight reduction, prepreg CFRP gives ski manufacturers more control over torsional stiffness properties and provides skiers more power and control on the slopes. CFRP skis also exhibit less fatigue than GFRP skis, which Hunt says can lose their “pop” (i.e. springiness or reaction time) after a few weeks. Prepregs can also remove the largest part of human error from the composite-building equation, reducing the likelihood of weakness for finished parts and increasing the likelihood for part consistency.