In the first part of this blog series we compared the flexibility of acrylic and polycarbonate. We showed that 0.47″ Polycarbonate is 20-25% more flexible than the same thickness Acrylic under simulated hockey player impact conditions. This increased flexibility could potentially lead to a reduced number of player concussions and reduce concussion severity.
In this article we will discuss how the thickness of the shielding affects the flexibility. You would traditionally use 0.47 thick acrylic sheet for spectator shielding. As Acrylic can break, it is not advisable to go thinner than this for spectator shielding. Indeed, some hockey arenas even increase the thickness to 0.545″ to prevent breakage, unfortunately increasing the rigidity in the process.
Polycarbonate does not suffer from the same breakage problems as Acrylic. Therefore it is possible to reduce the thickness without having the risk of material breaking. We wanted to see how reducing the thickness of the Polycarbonate affected the flexibility. We tested 0.47″, 0.39″ and 0.31″ Polycarbonate under simulated hockey impact conditions. A 180lb weight was used to hit the shielding at a speed of 14mph. It was found that 0.39″ Polycarbonate was 40% more flexible than 0.47″ Polycarbonate. We also found that 0.31″ Polycarbonate was 45% more flexible than 0.47″ Polycarbonate. We concluded that the largest benefit in flexibility was in reducing the Polycarbonate from 0.47″ to 0.39″. Further reductions to 0.31″ only had marginal benefits.
Overall changing from 0.47″ Acrylic to 0.39″ Polycarbonate increased the flexibility by over 60%; a significant change from a player safety perspective. Even with this increased flexibility and reduced thickness, the Polycarbonate would virtually eliminate the current breakage issue.
Another factor to consider for arena safety is that of weight reduction. Changing from 0.545″x50″x80″ Acrylic to 0.39″x50″x80″ Polycarbonate reduces the sheet weight from 90 lbs to 65 lbs. This decrease is very significant when considering the safety of arena personnel. Risks include lifting the panels into place and panels falling into the crowd after player impact.
The increased flexibility of the panel causes slightly increased movement of the panel in the frame. A 0.47″ Acrylic sheet moved 0.34″ in the frame whereas the 0.39″ Polycarbonate moved 0.71″ in the frame. When the rink installer designs the framing they need to consider this increased movement. HighLine can provide assistance if required.