Signage material selection is a vital part of the specification process. It affects the longevity of display surfaces, which of course has fundamental implications for the visual effectiveness and the financial payback of the signage project. Hence, it is important when specifying to take into consideration the impact of U.V. degradation on signage materials.
by Paul Roseblade
In Australia, we have some of the world’s highest U.V. ratings from the sun. Ultra Violet light is part of the natural spectrum of sunlight and has degrading effects of many materials over time. It is the ever-present enemy of outdoor graphics, so attention must be given to managing its effects.
U.V. incidence varies geographically and generally gets higher as you go north. Areas north of Brisbane, for instance, have much higher U.V. levels than the southern zones.
Some materials are used extensively due to their ability to cope with U.V. For instance, acrylic has superior U.V. performance compared to some other plastics. Polycarbonate, on the other hand, can turn yellow over time if not treated properly. Some polycarbonate have a transparent U.V. filter on one side and so care must be taken to use this as the outside face of course.
Digital prints are especially susceptible to U.V. degradation outside and so U.V. laminates have been developed to combat this. The laminate is usually a clear film which is bonded to the digital print substrate, thereby providing a filter between the sun and the ink. This works much like the sunscreen we apply to our skin, which provides a barrier between us and the U.V. light rays.
U.V. laminates vary in quality and must be paired with the appropriate printed substrate. Improperly paired laminate/substrate combinations can fail in ways like shrinking, peeling or cracking.
Of course, paint also is subject to U.V. attack. In Corporate Imaging we tend to use bright, vibrant colours, which are generally the backbone of the client’s marketing livery. Therefore colour retention is super important so your bright corporate red applied today doesn’t fade back to a nasty bubble-gum pink in a few months!
Aluminium Composite Material (ACM) panels are used extensively for a number of reasons and its ability to withstand U.V. attack being one of them. Good quality outdoor rated ACM has a factory applied paint surface that has extremely good U.V. defence properties. This enables it to maintain its colour and gloss level under full outdoor conditions.
Finally, signage vinyl also varies widely in quality and cost. Two vinyls side by side can be identical on day one, but be streets apart after time outdoors under U.V. attack. It is therefore essential that the material specified be done so appropriately to meet the clients expectations of lifespan.