Installation Instructions

SABIC Innovative Plastics 17
Mechanical Properties
Impact Strength
Lexan Thermoclear sheet has outstanding impact
performance over a wide temperature range, -40°C to
+120°C, and also after prolonged outdoor exposure.
Hail Resistance
As a roof glazing material Lexan Thermoclear 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 buckling.
In a test developed by the Dutch Testing Institute
TNO, samples of Lexan Thermoclear sheet have been
subjected to simulated hail-stones of varying diameters
without signicant damage.
A test sample is clamped into a metal frame and
polymide balls of varying diameters are red at the
surface of the sample using a pressurized airgun.
Table 5: Hail Simulation Test Results
Material Ball diameter
0,79”
Acrylic multi-wall sheet
t=0,63”
23-46 ft/s
Float glass t=0,16” 33 ft/s
Lexan Thermoclear sheet
t=0,39”
>69 ft/s
Lexan Thermoclear sheet
t=0,63”
>69 ft/s
Equilibrium velocity
of hail stones in practice
>69 ft/s
In practice, hail-stones with a diameter of 20 mm can
reach a terminal velocity of around 21 m/s. Under these
conditions materials such as glass and acrylic fail.
It should be noted that when the glass and the acrylic
are tested their failure characteristics are typically
brittle, whilst the Lexan Thermoclear showed ductile
behaviour: upon impact the ball will leave indentations
but the sheet will not break (See g. 4).
SABIC Innovative Plastics offers a Ten Years Written
Limited Warranty on Lexan Thermoclear sheet covering
loss of strength or impact due to weathering.
4. Represends material failure
at this speed
Polyamide balls
Lexan Thermoclear sheet
Pressurised gun
4