When you think of ski slopes and snowmen, you probably don't have potato flakes or Snowflex® in mind, but people in the movie and ski industries sure do. For them, artificial snow is far more versatile than the traditional flakes and flurries, according to the Jan. 19 issue of Chemical & Engineering News, the weekly newsmagazine published by the American Chemical Society, the world's largest scientific society.
Ski resorts, filmmakers and anyone else in need of a winter wonderland have lots of options when it comes to creating a snowfall or a ski slope indoors or out any time of year. Snowmaking can be a tricky task though, says the magazine, depending on what role the snow must play.
For skiing, snowboarding and other winter sports, fake snow must look, feel and act like the real thing. Machine-made snow has been refined by the ski industry and depends more and more on chemicals and new materials to be as realistic as possible, says the magazine.
Most artificial snow made for skiing and snowboarding still relies on good old frozen water, but the trick is using seed materials. The seeds essentially serve as a nucleus around which water molecules can be formed into ice crystals.
As long as it's cold enough (15-20 degrees F) just about any impurity can serve as the seed. Calcium, magnesium ions, or impurities such as clay particles or organic matter all will work well. If it's not cold enough (23-30 degrees F), more complex seed materials must be added to the water in order to form the crystals. Silver iodide, soaps and detergents, and fungi or lichens are some of the materials that have been used.
The most popular seed additive, according to the magazine, is Snomax®, a freeze-dried protein powder that produces very realistic-looking snow.
A newcomer that is making a big impact in the artificial snow market is Drift, an additive that allows water to freeze more quickly and speeds the preparation of the slopes.
If all else fails, there are "dryslope" products sort of like snow carpets that can be rolled out and used in any temperature by skiers and snowboarders. One such dryslope product is Snowflex a carpet-like mat with a slippery surface backed with a shock-absorbing pad that can be laid down to create an instant slope. Built-in water tubing keeps the surface of the mat wet and helps reduce friction
Fake snow isn't limited to the ski trails and moguls. More than 100 different materials are used on movie and television sets and the stage to fool audiences into feeling a winter chill. Here, the faux snow has to last and withstand powerful lights.
Paper, starch and cellulose make good falling snow that can be sprinkled down onto a scene and kept aloft by fans, says the magazine.
If the movie producer needs deep drifts in the background, firefighting foam works well... as long as actors don't walk on it.
And for amazingly realistic-looking onscreen snow, instant mashed potato flakes have the starring role, according to the magazine, with two caveats. Close-up shots still look like potato flakes and if they get wet, you end up with mashed potatoes all over the set.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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