This would explain why diving helmets use polycarbonate faceplates - in
the absence of a pressure differential, the cold-flow characteristic of PC
makes it safer in a working environment?
-Sean
Phil Nuytten wrote:
Rick: Note that the link was on the blowing of polycarbonates -
Might want to think about the 'cold-flow' characterisrics of PC - that
what allows it to 'absorb' incredible levels of point loading that would
shatter acrylics like plexi-G - the material attempts to flow away from
the impact and dissipates the energy in that fashion. This same ability
will cause it to creep easily and deform under a continously applied load
such as that induced by external pressure. That's why you don't see Lexan
view ports or domes used in a chambers or vessels with significant
pressure differentials.
----- Original Message -----
*From:* Rick & Marcia <mailto:empiricus@telus.net>
*To:* personal_submersibles@psubs.org
<mailto:personal_submersibles@psubs.org>
*Sent:* Wednesday, October 21, 2009 10:58 AM
*Subject:* Re: [PSUBS-MAILIST] canopy/bubble forming
This is an excellent link for anyone wanting to form their own
canopies or bubbles:
http://www.eng-tips.com/viewthread.cfm?qid=213295&page=4
<http://www.eng-tips.com/viewthread.cfm?qid=213295&page=4>
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