Giving lions a better zoo and patrons a better view without inviting real danger meant using extra strong safety glass in the clear barrier screen. The enclosure's 17-ft-high glass walls include 60 panels of laminated glass starting near ground level, mounted using horizontal line supports at the top and bottom.
The clear screen starts with 8-ft-tall, 4-ft-wide laminated glass panels made of four layers of tempered 1/2-inch-thick extra clear (low-iron) glass, alternating with three layers of clear 60-mil SentryGlas ionoplast interlayer from Trosifol. It's a new style of multi-layered glass often used in high-security situations, to provide durable barrier strength plus extra clarity.
"It can take the force of a 2.5-ton truck at 40 miles an hour, which is considerably more than any lion," said Ron Kagan, executive director of the Detroit Zoological Society Executive Director.
Trosifol / Kuraray
Higher-mounted panels of the glass screen are made of thinner laminated safety glass, completing the needed barrier height while retaining the feeling of openness. Because the glass screen is so clear, the zoo has added decals of birds in flight, to help prevent birds from flying into the glass unaware of its presence.
Trosifol / Kuraray
The zoo glass gives patrons an improved view with minimal visual interruption from glass structural supports. SentryGlas ionoplast interlayer from Trosifol is up to 100 times stiffer and 5 times tougher than traditional safety glass interlayers, which allows larger, more expansive panels with lower deflection for extra resistance to breakage in thinner laminates. the moisture resistance of SentryGlas also allows for frameless "open-edge" glass edges, further opening the vision area in glass viewing screening applications.
