Re: Absorb UV Light?

From: Douglas Mitchell (
Date: Wed Feb 11 1998 - 14:06:50 EET

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?
> Thanks,
> Michael W Miller (
> 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
>-- 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.


Doug Mitchell

For more information about the rp-ml, see

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