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Light transmission thru various plastic
3

Light transmission thru various plastic

Light transmission thru various plastic

(OP)
I need to construct a lamp using some sort of plastic about an inch thick to transfer light from one edge to the other.  I need to know which material transmits the most light (least lumin loss) from a source  - or which material has the least "resistance", so to speak.  I need to put a light bulb near the edge of some sort of plastic, I was thinking either a piece of polyester resin,  a urathane, or a polymethyl methacrylate (perspex), and I what I'm asking is which one (or one I haven't mentioned out of ignorance) will deliver the largest percentage of the source light out the opposite edge.  

Thanks
Ken

RE: Light transmission thru various plastic

2
For this applications, acrylic (aka polymethyl methacrylate, aka PMMA) should have the highest optical transmission of polymers (~ 92%).  The missing 8% is due to reflection, 4% from each surface.

RE: Light transmission thru various plastic

I did a quick check of optical-quality PC (polycarbonate) vs. optical-quality PMMA, and it looks like PMMA is just a bit better in optical transmission -- 92% vs. 89%.  This data is for Cyro Acrylite DQ-501, which was measured according to DIN 5036/5033, and for Bayer Makrolon DP1-1265, which was measured according to ASTM D 1003.  You can review the datasheets for these two grades at the following websites:

http://www.cyro.com/Internet/Home.nsf/Main2!OpenPage

http://bayerplastics.com/BC/AE/products/types/datasheet.jsp?ref=ASTM&grade_id=31&pid=1

Another possibility is one of the DuraStar grades of polyester from Eastman.  It looks like they are in the range of 89-91% as well.  You can obtain more information on their website:

http://www.eastman.com/Product_Information/polymers.asp

RE: Light transmission thru various plastic

COC (Cyclic Olefinic Copolymer) materials can reach 93% (ASTM D1003). They can be sensitive to skin oils though, but would be fine if the part is on the interior of the lamp and not handled during use.

Regards

Bryan Deacon
Ticona UK Limited
www.ticona.com

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