Wednesday, February 1, 2012

Bands and heat: One more test

It is very very cold right now here in Germany - a high pressure system coming in from Siberia.

I measured minus 8,4 centigrade noon temperature - that is -18 Fahrenheit.

So I took my band test system outside, stretched the bands and let it sit for 30 minutes or so.

The bands lost ALL flexibility! No more rubber like behaviour. I saw the "wrinkled" look I noticed a year ago after shooting a sling-x-bow out in the cold.

About five secs of the heatgun restored the rubber in full.

This is one more proof: Rubber stores all of its energy thermally. You stretch out a band, it warms up. Release it, it cools down. Cool it down while stretched, and the stretchiness decreases. Cool it down low enough and there is no more stretchiness.





2 comments:

  1. Krass! schleudern ist demnach mehr was für den Sommer, den Süden oder den Keller :)
    Ich hätte nicht gedacht dass er wirklich gar nicht mehr geht.

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  2. Tobias, denk dran: Wenn Du ausziehst, ist das Band 15 Grad wärmer. Bis ca. 15 Grad unter Null kannst Du also immer noch schießen. Erst wenn es noch kälter wird, müssen die Bänder warm gehalten werden.

    In diesem Test habe ich die ausgezogenen Bänder erkalten lassen - daher die Effekte.

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