Scratching polycarbonate
Polycarbonate is a clear plastic material that is extremely strong and almost totally resistant to breakage. It is a perfect choice for hockey spectator shielding. However it is possible to scratch the plastic surface a lot easier than it is to scratch glass. To reduce the risk of surface scratches, plastic sheet makers have developed a clear hard coating. The coating is put on the surface of the sheet. This coating is often a clear siloxane hard coat that is permanently bonded/cured to the surface using an oven. No difference can be observed between coated and uncoated plastic other than the fact that there is improved scratch resistance. The downside of a coating is that it adds about $100 to the cost of a 4′ x 8′ sheet. The cost can quickly add up when shielding for an entire rink is being installed.
When we started testing polycarbonate in competitive hockey rinks, we believed helmets, pucks and sticks would cause sheets to scratch. We anticipated that we would need to use the more expensive hard coated polycarbonate. After considerable testing in the US and extensive use in Sweden, we have not observed any damage to uncoated polycarbonate. We can not therefore recommend using hard coated polycarbonate solely for the aim of eliminating scratches.
Rubber puck marks
There is also the issue of rubber puck marks on the glass. We noticed that the softer surface of uncoated sheets results in slightly more puck marks than on coated plastic sheet. It is also slightly harder to remove these puck marks. However, even on uncoated plastic, the amount of marks is not significantly greater and removing them is still relatively easy. Coated plastic sheet offers only a very slight advantage over uncoated plastic sheet. This fact makes it extremely difficult to justify the additional expense except at the highest levels of hockey. The Swedish-Elite-League uses coated polycarbonate sheets, whereas training arenas, lower level leagues and community rinks use uncoated polycarbonate sheet.
At HighLine Polycarbonate we are able to offer a coated polycarbonate sheet for hockey spectator shielding. Although for the majority of customers, we recommend the uncoated version as it is a much better value.
Protective films?
There is another product that is starting to appear on the market. The supplier adds a multi-layer plastic film to the surface of the plastic sheet. The rink owner can remove a layer of film when it becomes marked or damaged, leaving a fresh layer underneath. The product consists of four or more layers of film. The tear-off film is a similar concept to the tear-off strip technology used on NASCAR windshields. The manufacturer claims that these films can reduce scratches to the sheet and make it easy to clean the sheet. The film layers do have several downsides. It is expensive to install the film initially. The cost of replacing the film after all of the layers have been used is also expensive. Also the rink downtime to replace the film can be significant.
We are closely monitoring this technology to see if it is practical for the hockey market. Currently we don’t recommend spending a significant amount of money to use this technology to protect against damage. We have not seen any real level of damage on uncoated polycarbonate. As for cleaning, it is certainly quick to remove tear off strips, but cleaning uncoated polycarbonate does not take long. The main limitation in cleaning with this the technology is that you only get a limited number of tear-off strips. You then need to spend time and money to replace the system. With uncoated polycarbonate, you can clean whenever you want for very little effort.
The film can have some delimitation issues. We have seen some rink installations where the film become partially detached from the plastic sheet. We do expect that the supplier to resolve these delimitation issues eventually.
Conclusion
In conclusion, for hockey spectator shielding we recommend that uncoated polycarbonate sheet gives the best balance between cost and performance. For higher end hockey applications, there could be some advantage of upgrading to coated polycarbonate. For most customers we do not see many advantages of the tear off strips at this time. Although if the technology improves and the cost of the strips comes down, it may be a technology to consider.