Ski wax is a material applied to the bottom of snowboarders, including skis, snowboards, and toboggans, to improve their friction performance coefficients under various snow conditions. The two main types of candles used on skis are sleigh candles and handrail candles. They overcome kinetic friction - to be minimized with a glide wax - and static friction - to be achieved with a candle handle. Both types of wax are designed to be matched to various snow properties, including crystal type and size, and moisture content of the snow surface, which varies with temperature and history of snow temperatures. Glide wax is chosen to minimize shear friction for alpine and cross country skiing. Grip wax (also called "kick wax") provides on-snow traction for cross-country skiers, as they step forward using classic techniques.
Modern plastic materials (eg, high modulus polyethylene and Teflon), used on a ski runway, have excellent sliding properties on snow, which in many circumstances reduce the added value of glide wax. Similarly, uni-directional textures (eg fish scale or micro-hair scale) underfoot on cross-country skiing can offer a practical replacement for candle holders for the skier, using classical techniques.
Video Ski wax
Histori
Johannes Scheffer at Argentoratensis LapponiÃÆ'Â| (Lapland History) in 1673 gives what may be the first recorded instruction for ski wax applications He advised skiers to use pine tar and rosin pitch. Ski waxing was also documented in 1761.
Starting around 1854, California gold miners rush organized organized downhill skiing. They also found that bleached-doped bases of vegetables and/or animal compounds helped to increase ski speed. This led to some of the first commercial skiing wax (though they contain no candles at all), such as Black Dope and Sierra Lighting ; both consist mainly of sperm oil, vegetable oil and pine. However, some instead use paraffin wax candles that melt into the ski base, and this works better in cold conditions.
Pine tar on a wood ski base has proved effective for skiing as a transport for centuries, as it fills wood pores and creates hydrophobic surfaces that minimize suction from water in the snow, but has sufficient roughness to allow traction for forward movement. In the 1920s and 30s, new varnish was developed by European companies as a long-term ski base. A significant advance for cross-country racing is the introduction of clisters, for good traction in granular snow, especially in spring conditions; klister discovered and patented in 1913 by Peter ÃÆ'ËÅ"stbye. In the early 1940s, a Swedish chemical company, advised by Olympic cross-country skier Martin Matsbo, started the development of oil-based candles, using paraffin wax and other blends. In 1952, leading brands such as Stores, Swix, and Rex provided a series of color coded, temperature-adjusted temperatures.
In the last quarter of the 20th century, researchers discussed the twin problems of water and impurities attached to skis during spring conditions. Terry Hertel discussed both issues, first with the use of new surfactants that interacted with the wax matrix in such a way as to effectively reject water, a product introduced in 1974 by Hertel Wax. Hertel also developed the first fluorocarbon product and the first spring wax that repels and makes the surf surface slippery for alpine skiing and snowboard spring time. This technology was introduced to the market in 1986 by Hertel Wax. In 1990, Hertel filed a US patent on "ski wax for use with snow skis jointed", containing paraffin, hardening wax, about 1% per fluoroether diol, and 2% SDS surfactant. In the 1990s, chief chemist Swix Leif Torgersen invented glide wax additives to dissipate pollen and other snow feces - a problem with soft gentle candles during long-distance races - in the form of an ironing fluorocarbon that can be ironed into the ski base. The solution is based on the work of Enrico Traverso in Enichem SpA, which has developed a fluorocarbon powder with a melting temperature of just a few degrees below polyethylene sintered, patented in Italy as a "ski lubricant consisting of paraffin wax and hydrocarbon compounds containing perfluorocarbon segments".
Maps Ski wax
The science of shear in the snow
The ability of a ski or other runner to glide over the snow depends on the nature of snow and skis to produce the optimal amount of lubrication from melting snow with friction with skis - too little and skiing interact with solid snow crystals, too much and the attraction of meltwater capillaries inhibits skiing.
Friction
Sebelum ski bisa meluncur, ia harus mengatasi nilai maksimum gesekan statis, , untuk kontak ski/salju, di mana adalah koefisien gesekan statis dan adalah kekuatan normal dari ski di salju. Gesekan kinetik (atau dinamis) terjadi ketika ski bergerak di atas salju. Koefisien gesekan kinetik, , kurang dari koefisien gesekan statis untuk es dan salju. Gaya yang diperlukan untuk meluncur di salju adalah produk dari koefisien gesekan kinetik dan gaya normal: . Baik koefisien statis dan kinetik dari friksi meningkat dengan suhu salju yang lebih dingin (juga berlaku untuk es).
Sifat-sifat salju
Snowflakes have many shapes, even when they fall; among them are: star-like dendrites like six stars, hexagonal needles, platelets and cold pellets. Once the snow accumulates on the ground, debris immediately begins to undergo a transformation (called metamorphosis ), due to changes in temperature, sublimation, and mechanical action. Temperature changes may be from room temperature, solar radiation, rainwater, wind, or material temperature under the layer of snow. Mechanical actions include wind and compaction. Over time, snowfall tends to consolidate - the crystals become truncated from breaking or losing mass by direct sublimation from solid to gas and with freeze-thaw, causing them to combine as coarse and granular ice crystals. Colbeck reports that fresh, cold, and man-made snow all interact more directly with the ski base and increase friction, indicating the use of harsher candles. In contrast, older, warmer, and denser snow represents lower friction, in part because of increased grain size, better promoting a water layer and a smoother surface than the softened wax crystal is indicated.
- Newly falling and metamorphosed snow crystals
Ski swipe properties
Colbeck offers an overview of the five processes of friction skiing in the snow. They are: 1) resistance due to plowing snow from the road; 2) snow deformation where skiing travels; 3) lubrication of skiing with a thin layer of melted water; 4) water capillary charm in snow to ski base; and 5) snow contamination with dust and other non-slippery elements. Piracy and deformation are associated with ski interactions, overall, with snow and can be ignored on hard surfaces. Lubrication, capillary appeal and contamination are problems for ski and wax pads that are applied to reduce shear friction or achieve adequate grip.
Typically, ski glide melts thin and temporary films from the water lubricant layer, which is caused by the heat friction between skiing and snow as it passes. Colbeck shows that the optimal water film thickness is in the range between 4 and 12 ? m. However, the heat generated by friction can be lost by conduction to cold skis, thereby reducing the production of the melting layer. At the other extreme, when the snow is wet and warm, the formation of heat creates a thicker film that can create an increase in capillary resistance at the bottom of the skis. Kuzmin and Fuss point out that the most advantageous combinations of the nature of ski base materials to minimize sliding friction skiing in the snow include: increased hardness and lower thermal conductivity of the base material to promote meltwater generation for lubrication, wear resistance in cold snow, and hydrophobic to minimize capillary suction. These attributes can be achieved on a PTFE basis, which reduces the value added by glide wax. LintzÃÆ'Â n n reported that factors other than wax are much more important in reducing friction on cross skate skiing - the curvature of ski and snow conditions.
Glide wax
Glide candles can be applied for alpine skiing, snowboards, skate skiing, classic skiing, back-country skiing and skiing touring. Traditional candles consist of solid hydrocarbons. High-performance "fluorocarbon" waxes also contain fluorine which replaces some hydrogen atom fractions in hydrocarbons with fluorine atoms to achieve a lower coefficient of friction and higher water repellency than can be achieved by pure hydrocarbon wax. Wax is adjusted to hardness to minimize shear friction as a function of snow properties, which includes the effects of:
- Age : Reflects metamorphosis of sharp and well-defined snow crystals, when new, but with aging become damaged or cut off by wind action or rounded into ice-freezing frosts, which they all affect the coefficient of ski friction.
- Moisture content : The percentage of mass that is liquid water and can create suction friction with a ski base during a slide.
- Temperature : Affects the shear flexibility that can melt the snow crystal at the interface between skiing and snow.
Properties
Various gliding candles are adjusted for a certain temperature range and other snow properties with a variety of candle hardness and other properties that overcome the repositioning of moisture and dirt. The wax slide violence affects the melting of the snow to lubricate its course above the surface and its ability to avoid suction from melting the water in the snow. Too little melt and sharp edges of snow crystals or too much suction blocking the way of skiing. The tipping point between the crystalline type that dominates the shear friction and moisture content predominates around 26 ° F. The harder wax overcomes the cooler, drier or more abrasive snow conditions, while the softer wax has a lower coefficient of friction, but faster abrade. The wax formulation incorporates three types of wax to adjust the coefficient of friction and durability. From hard to soft, they include synthetic wax with 50 or more carbon atoms, microcrystalline wax with 25 to 50 carbon atoms and paraffin wax with 20 to 35 carbon atoms. Additives for such waxes include graphite, teflon, silicon, fluorocarbons, and molybdenum to increase glide and/or reduce dirt accumulation.
Apps
Glide wax can be applied cold or hot. Cold applications include, rubbing hard candles like crayons, using liquid wax or spray wax. Hot wax applications include the use of heat from iron, infrared lights, or "hot box" ovens.
Basic material
The role of the gliding wax is to adjust and improve the skiing friction properties to the snow properties expected to be encountered on the spectrum from cold crystalline snow to saturated granular snow. Modern skiing bases are often made of ultra-high-molecular polyethylene (UHMWPE). Kuzmin asserted that UHMWPE is not porous and can not withstand candles or water, so there is no possibility to fill the pores; furthermore, he asserted that UHMWPE is very hydrophobic, meaning that wet snow does not quite hamper skiing and glide candles offer little additional ability to resist water. He noted that clear bases are more durable and hydrophobic than those with carbon content. The same authors assert that texture is more important than surface chemistry to create the optimal balance between overly dry surfaces (not slippery enough) and too wet (ski subjects for suction style). In warm and humid snow, texture can help break down the stunted capillary attraction between ski and snow. Giesbrecht agrees that the low wetting angle of the ski pad is key and also emphasizes the importance of surface roughness levels on a micrometer scale as a function of cold snow-snow temperatures supporting a finer and wetter surface, warmer snow supporting textured surfaces.
Candle handle
Cross-country skiers use candle holders (also called "wax kicks") for classical rolled skis to provide traction with static friction in the snow that allows them to push themselves forward in the lowlands and hills. They are applied in the area under the foot of the skier and are elongated, somewhat forward, formed by the camber of the classic ski, called the "grip zone" (or "kick zone"). The presence of camber allows the skis to grip the snow, when its weight in one ski and ski is fully flexed, but minimizes drag when the skis are weighed the same and thus less fully flexed. Wax Grip is designed for a certain temperature range and type of snow; properly selected gypsum waxes are not enough to bring down the ski slopes that have the right camber for the skier's weight and for snow conditions. There are two substances used for candle hold: hard candle and clitor.
- Hard candlesticks : traditional paraffin-based waxes by mixing - for snow consisting of relatively intact crystals and not much changed with packing or freezing. Admixtures, which include dyes, rubber, resin, resin and colophony, adjust the hardness of the wax to adjust the effectiveness of its grips to a specified discrete temperature range (from about -25 ° F to 35 ° F); candles are assessed and color-coded according to this temperature range. Stronger grip candles are designed for cooler snow temperatures, but less grip in warmer temperatures. Conversely, a softer wax in cold temperatures creates sufficient friction and melting so that the melt layer can accumulate and increase the frozen snowfall.
- Klister : sticky ointment, which may contain a combination of rosin, wax, solvent and fat - with formulations adapted to snow consisting of coarse crystals, having been changed through freeze -thaw or wind blown, and adjusted for a certain temperature range. Spray-on clisters are more comfortable than the ones applied from the tube. Incorrect compatibility of clister to snow conditions can also cause ice sheets.
Some "waxless" skis have scales of fish or other textures to prevent skiers sliding backwards. Mountain climbers use climbing leather that is fitted temporarily to provide an uphill grip, but usually release it to descend.
Solvent wax
Candles can be dissolved by non-polar solvents such as mineral spirits. However, some commercial wax solvents are made from citrus oil, which is less toxic, more difficult to flare, and softer on the ski bed.
Health and environmental impact
Health impact
Skiing candles may contain chemicals with potential health effects including perfluorinated chemicals. Perfluorinated carboxylic acid levels, particularly perfluorooctanoic acid (PFOA), have been shown to increase in ski wax technicians during the ski season.
Environmental impact
When skiing, the friction between snow and skis causes the wax to fade and remain in the bag of snow until the spring melts. Then the expanse of snow flows into the watersheds, rivers, lakes and rivers, thus changing the chemistry of the environment and the food chain. Perfluorocarbons in heat-resistant ski wax, chemically and biologically stable, and thus environmentally persistent.
References
Further reading
- Brady, M. Michael; Torgersen, Leif (2001). Waxing and Skis Treatment and Snowboards . Wilderness Press. ISBN: 9780899973036.
- Brown, Nat (1999). Full Guide for Cross-country Skiing . The Mountaineers Books. p.Ã, 140. ISBNÃ, 9780898866001.
- Masia, Seth (April 1989). Alpine Ski Treatment and Repair (Revised ed.). Contemporary Books. ISBN: 0809247186.
Source of the article : Wikipedia
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