Most Plexiglass will absorb wavelengths below 380nm. I have tested Cyro
UF-7 which starts transmitting at 390nm, OP-2 & OP-3 which starts at about
400nm. Use OP-2, since its cast, its easier to machine.
You can contact Cyro at 203-799-4066.
If you want, I can fax you a copy of the Spectral Transmittance chart.
Also you may take note that Aluminum reflects UV about 85% so be careful of
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Torrance, California 90505
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From: Douglas Mitchell <email@example.com>
To: Miller, Michael W <Mike.Miller3@PSS.Boeing.com>; 'RP Mail List'
Date: Wednesday, February 11, 1998 4:57 AM
Subject: Re: Absorb UV Light?
>On Feb 10, 3:58pm, Miller, Michael W wrote:
>> Subject: Absorb UV Light?
>> We are getting surface skinning (cured resin) in the right front corner
>> of our SLA500 near where the laser parks between layers. Our 3d
>> maintenance person believes it is caused by laser reflection off all the
>> resin spills on the cover plate. It has been suggested we dip the cover
>> into hot water to soften and then remove the spilled resin. An
>> alternate solution might be to paint? or apply some material in the area
>> that would absorb rather than reflect the UV. Any suggestions as to
>> what cheap and readily available material effectively absorbs UV?
>> Michael W Miller (Mike.Miller3@PSS.Boeing.com)
>> The Boeing Company MS 17-PE B-XT62
>> Propulsion Experimental Hardware 206-655-3289
>> Rapid Prototyping 655-4366 Lab 655-4365
>> For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
>>-- End of excerpt from Miller, Michael W
>When I went through SLA500 training back in the early days (Oct. 1990),
>3D had placed a small square of plexiglass at the corner for the laser
>to rest on. They claimed that the plexiglass disbursed the beam and
>kept it from bouncing back into the vat. I don't believe that they
>are still using this, but it would be a simple thing to try. It was
>a square of about 50 mm per side.
>For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
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