While the several Arcylic manufacturers declare the light transmission of a backlit sheet, illuminated with a standard white source, not well known is the behaviour of mono chromatic source with different colour of PMMA sheets.
The experiment below described did consider 3 different LED (Orange, Blue and White) with some typical Acrylic colour sheets used in sign industry. Set to 100% the amount of light measured thru a translucent sample, illuminated with the 3 LEDs modules, the relative percentage of transmitted light have been recorded and the results are shown in the attached picture.
As expected, Orange light passes very well thru “warm” acrylic sheets, while the performance starts to decrease with Red, Green and Blue. Obviously, the Blue light has an opposite behaviour, doing well just with Green and Blue. White LED (Daylight) is unsatisfactory with Red and Blue acrylic.
Once again it’s clear that the use of “Standard cool white” LED with any coloured sheet can lead to some disadvantage in terms of amount of modules used - in order to reach a satisfactory brightness of the sign - and a consequent waste of energy. A proper selection of light source and acrylic sheet represents the basis for achieving a good result in terms of eye-catching, brightness and energy consumption.