PC IR Transmission

[Metronic]

Hello,

I'm searching for the absorption / transmission spectra of polycarbonate in the infrared at wavelength at about 10µm. The background is to use PC as an optical shielding of the CO2 Laser radiation more specific against 10,6µm straylight.

Does anyone know where to get it?

Best regards

 

[patprimmer]

The scond result of a sit google search as thread334-216368

Regards
Pat
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[Metronic]

Sorry but there is nothing relevant to the question in it.
More precisely I'm for the extiction coefficient for PC at 10600nm, which is the wavelength of the CO2 Laser.
I know that PC is used as absorber Material for laser application using CO2 Laser, but without knowing the (more or less) exact values of the absorption coefficients it is problematic to calculate a required thickness of a PC plate.

Regards

 

[lumenharold]

You might find this material helpful. Kentek supplies a series of certified laser safety acrylic and polycarbonate materials in different colors.

http://www.kenteklaserstore.com/ProductInfo.aspx?productid=ACRP-CO2D

Harold
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[patprimmer]

They only show u to 3000 nano in the graphs I have, but it appears to stay below 20% transmission at 2200 to 3000.

I think that is inadequate information for you. Maybe Sabic, or Dow or Mitsubishi Gas or Bayer Materials Science can provide details at your specified wavelengths.

You could of course buy a 3mm thick sheet and measure it yourself and calculate from there.

Regards
Pat
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[Metronic]

Thank you for the infos. I know the materials companies like Kentek, Uvex or Laser-Vision etc. are offering but having a look at the prices they have for small pieces of PC shows me that a housing made fo these materials would may be cost more than the laser itself.
Furthermore it seems that these PC's do have additional coatings maybe dielectric coatings which makes them very expensive and which gives you an totally different reflection/absorption/transmission spectra of the plate.
Also at the named sites of the manufacturs of PC until now I could not find helpful information, so I'm going on searching.

What I'm looking is the spectra of pure simple polycarbonate or maybe also simple PMMA

Regards

 

[lumenharold]

Yes, they are expensive. But so is the liability if someone gets hurt. We specify the Kentek material when we produce enclosures for test equipement with high powered IR lasers because the material comes with certification and the company is liable for personal injury. We enclose the fixture with opaque materials and provide small viewing windows of the Kentek material. It's more cost effective for the client that way.

You can chew up a lot of time researching and testing materials or spend the money for certified materials. I've never had much luck finding curves beyond 800nm or so (depending on the material since most applications are for day light/visible). I can't know all the restrictions you are dealing with, but that's my two cents. Best of luck.

Harold
SW2009 SP2.0 OPW2009 SP0 Win XP Pro 2002 SP3
Dell 690, Xeon 5160 @3.00GHz, 3.25GB RAM
nVidia Quadro FX4600

http://www.lumenflow.com

 

[IRstuff]

So why not make it out of sheet metal, or use something certified? If someone can see through it, as in the case of PC, then they'll be tempted to continue looking at it, increasing the risk.

Seems to me to be highly dubious to "roll" your own approach. One lost eye will cost you and your company far more than the cost of using the appropriate materials.

TTFN

FAQ731-376

 

[patprimmer]

If the tried and tested and guaranteed material has coatings to do the job, then the result will be dependant on the thickness of the coating rather than the thickness of the plate. It will vary greatly if subject to abrasion or scratching.

Regards
Pat
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