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Bright Anodized Lighting Reflectors

1998

Hi,

I would appreciate it if anyone of you could provide me with information regarding the following:

(1) The degree of influence on the reflectivity of brightened anodized lighting reflectors at different level of anodizing thickness.

(2) How long will the reflectivity of brightened anodized lighting reflectors last under a normal indoor environment at different level of anodizing thickness.

(3) What is the market standard for light reflectors:-

i) performance shelf life

ii) reflectivity

iii) anodizing thickness

(4) Apart from bright anodizing of light reflectors, are there any other surface finishings that can be used or has been in used for light reflectors.

(5) What is the equipment used to measure the reflectivity of brightened anodized lighting reflectors as the normal gloss meters are ineffective due to the reflectors curve surface. Thank you.

Nick Lim
- Malaysia

Albright and Wilson [Richmond, VA] is one of several sources that might be able to give you answers to some of your questions.

James Watts
- Navarre, Florida
1997

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1998

James,

I am the chemist at ACA. Our specialty is coil anodizing for the lighting market. In response to your questions:

1) in general, the thicker the coating, the lower the total reflectance.

2) under normal conditions, reflectivity is independent of coating thickness; ie. the reflectivity should remain constant for the life of the reflector.

3) varies by product.Ask if you need detailed info.

4) matte finishes are also used in reflectors.

5) don't quote me here, because I'm not at work right now but I think our total reflectometer is manufactured by Technodyne.

Gerald Janssen
aluminum coil anodizing - Streamwood, Illinois

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1998

1. Al2O3 is not totally transparent, so the thicker the coating the more light is lost in transmission.
2. Indoor environments are fairly clean. Depending on the heat and wavelength of the light, reflector life should be 5-10 years minimum. Rules change with chemical or smoke exposure. Thickness is usually only important on the aggressiveness of the environment.
3. 3.i-?Don't know; 3.ii Probably goes the other way, reflectors are designed to deliver the light pattern based on the attainable reflectivity that can be held in the process; 3.iii-Indoor exposure coating thickness is probably 0.1-0.2 mil. industry avg.
4. DK. I've seen white paint but I'll leave this one to the industry experts.

There are large sphere reflectometers. Also a reflectometer manufacturer that has a 1/4" probe area which works well with reflectors.

Lee Branch
Richmond, Virginia