INTRODUCTION: The skiing community is in dire need of fluorine-free glide products with competitive performance to the soon-to-be fully banned fluorinated products. Silicones are affordable, low-toxic and hydrophobic compounds which may be useful glide enhancers to reduce ski-snow friction. METHODS: We tested a range of silicone oils with viscosities of 10-100 cSt. The friction on snow of full-size cross-country skis treated with oil was measured in a linear tribometer on dendritic new and aged snow at speeds of 22 km/h and air temperatures from -10 to +5°C. The hydrophobicity of the skis treated with oil and the reference ski with Swix HS wax was tested with a Krüss contact angle analyzer. RESULTS: For cold and dry conditions, silicone oils increased friction by as much as 60%, presumably due to the introduction of viscous shear forces in the thin oil layer. For warm and wet conditions, silicone oils reduced friction by about 10% due to increased hydrophobicity, but the oils were outperformed by the harder commercial glide wax. DISCUSSION/CONCLUSION: The performance window of pure silicone oils is narrow and only applicable in races where the entire course has snow with pre-existing water. Also, durability is expected to pose challenges. However, silicone oils or other silicone-based compounds may be highly valuable hydrophobic additives in solid fluorine-free glide products.
© Copyright 2023 9th International Congress on Science and Skiing, March 18 - 22, 2023, Saalbach-Hinterglemm, Austria. Published by University of Salzburg. All rights reserved.