Specialist Glass Products (SGP) supplied 12 bespoke toughened laminated glass panels for Yorkshire Wildlife Park’s new penguin enclosure, with the glazing forming a 33-metre-long underwater viewing wall.
The glass was originally specified as 48mm-thick triple-laminated panels using PVB interlayers. As the enclosure design developed and water pressure increased, the specification was revised. The PVB interlayers were replaced with SentryGlas, a rigid structural interlayer selected to provide greater strength and meet the increased loading requirements.
The panels were manufactured from 6m × 3.21m jumbo sheets, which SGP cut to size and edge-polished. The glazing also incorporated radius corners produced using CNC machining before undergoing toughening.
During toughening, the glass was heated to approximately 630°C and rapidly cooled to create surface compression and increase its mechanical strength. The panels were subsequently laminated using heat and pressure, bonding the glass layers with the SentryGlas interlayer. 
A secondary heat-soak test was also carried out to reduce the risk of spontaneous breakage caused by nickel sulphide inclusions in toughened glass.
Clarity was another critical requirement for the viewing installation. SGP used a crystal-clear interlayer to maintain high optical transparency across the large panels.
Source: SGP with additional information added by Glass Balkan
