the Hail resistance of Polycarbonat Sheet
Author : admin UpdateTime : 2013/10/31
As a roof glazing material Chiancess clear sheet is subject to extremes of weather;storms, hail-stones, wind , snowfalls and ice formation. Under these conditions, the product is virtually unbreakable and is able to withstand the subsequent temperature change to sunny conditions without breaking or bucking .
In a test developed by the Dutch Testing institute TNO, samples of Chiancess clear sheet have been subjected to simulated hail-stones of varying diameters without significant damage .
A test sample is clamped into a metal frame and polyamide balls of varying diameters are fired at the surface of the sample using a pressurized airgun.
In practice, Hail-stones with a diameter of 20mm can reach a terminal velocity of around 21m/s. Under these conditions material such as glass and acrylic fail.
It should be noted that when the glass and the acrylic are tested their failure characteristics are typical brittle ,whilst the Chiancess Multi-wall sheet showed ductile behaviour: upon impact the ball will leave indentations but the sheet will not break (see fig.1)
Chiancess offers a ten years written limited warranty on clear sheet covering loss of strength or impact due to weathering .