visibly opaque & IR Transparent

[racinej]

Does anyone know of a visibly opaque polymer film with high IR transparency.

Or does anyone know of an additive to polyethylene that signficantly reduces visible transmission, without affecting the its IR transmission?

Thanks

 

[IRstuff]

You could use what they use for sunglasses.

TTFN

 

[Compositepro]

Most plastics absorb strongly in the I.R. spectrum. You have to be very specific as to what freaquency you want to pass and what you want to block.

 

[IRstuff]

And, it depends greatly on what you're referring to when you use the term "infrared." Various polycarbonates and acetates are quite transmissive in the NIR, e.g., between 0.8 um and 2 um, and there are plastics, such as those found covering thermal motion sensors that are relatively transmissive in the 8-12 um regime.

TTFN

 

[racinej]

Ideally, I would like the visible spectra (400 - 700 nm) to be opaque or around 20-30% transmissive. I'd like the IR transmission (2 - 13 microns) to be as high as possible (80 - 90% transmissive).

 

[IRstuff]

And what ELSE do you want it to do? Otherwise, I'm just going to recommend silicon.

TTFN

 

[racinej]

The material needs to be flexible, and provide a tight seal. We have been using polyethylene, but we want to block out the visible spectrum.

 

[IRstuff]

http://www.fresneltech.com/pdf/POLYIR.pdf

You could add an IR cut-on filter

TTFN