The lighting of industrial manufacturing areas must always take into account of the different environmental conditions that exist in any factory plant. Lighting fixtures and sources must be adequately protected from heat, cold, humidity and volatile substances, such as dusts and gas, which may be generated by the different types of processes that are taking place.
What are the changes brought about by the new LED systems in this specific sector? We asked Gabriele Giaffreda from Osram Opto Semiconductors.
“The first entirely LED lighting systems for the industry – recalls Giaffreda – dated back to very recent times, especially when it comes to general lighting applications. It is a technology that has evolved thanks to the studies and the futuristic applications that are very different compared to the ones we knew before. The discharge lamps that were generally used in this sector did not pose particular issues connected with the factory’s environmental conditions, except for the risk of exposition if used under extreme conditions. Of course, lighting fixtures must ensure an adequate level of protection depending on the area in which they are used.
In any case, while discharge lamps have a short lifespan and must be replaced on a regular basis, LEDs, on the contrary, have an extremely long life – therefore reducing replacement costs – and the need to ensure protection from possible damages connected with the characteristics of the installation area must be faced in a different way.
When the first LEDs appeared, the declared life of 50,000 hours was a theoretical value, achievable only if the sources were used under ideal conditions. Today, manufacturers have a greater awareness of the potential of LEDs and have solved basic problems, such as, for example, heat dissipation, so we can say with a certain degree of safety that LEDs can last for even 100,000 hours, as long as certain environmental conditions are met. These conditions include temperature, humidity and also the protection from high concentrations of chemicals.
“We discovered – continues Giaffreda – that the high concentration in the environment of certain chemicals, such as, for example, some solvents used in paintings, may deteriorate the material used for the LED’s primary optic. In these cases, the luminous flux decreases and the LED is no longer capable of reaching the life expectancy it should. LED manufacturers like ourselves are very sensitive to this issue and we focus our efforts on the development of tests that are able to provide fixture manufacturers with indications on which chemicals in high concentrations could cause this problem.
To directly protect LEDs from any external agent, we need to encapsulate it, but this would largely reduce the luminous flux and therefore the overall efficiency of the lighting fixture. An example of LED application with extremely high protections is the automotive sector. In these cases, the LED must have a superior protection because it is directly in contact with high damaging and corrosive environments and it is connected with discharge gases and the vapours present at asphalt paving level.
The manufacturing features of LEDs continue improving with the multiplication of diverse applications: at the same time, the studies are fine-tuned leading to the adoption of the most suited materials and components capable of facing the various environments where the LED is used (think, for example, of the gold wire bonding that is widely applied in the automotive field).
Lab tests and field experience help us understand which chemicals in high concentrations can generate incompatibility with LEDs. In this way, manufacturers can insert “warnings” about the fact that in the presence of high concentrations of certain substances, the life of the lamp may be shortened.
Long lamp life is a fundamental advantage of LEDs and it is important to offer buyers serious guarantees in this regard. This is why at Osram Opto Semiconductors we provide manufacturers, who are willing to give information on the operation conditions of LEDs, with reliable and conservative instructions on the lamp life expectancy and duration.
- Posted by Redazione
- On October 24, 2016
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