Goggles

Discussion in 'General Science' started by Lightfire, Aug 28, 2011.

  1. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
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    Hello,

    I found some goggles and it has a mark on it "GUARANTEE UNBREAKABLE POLYCARBONATE LENS". what does it mean?

    I wanna use it for some of my experiments. pls. help

    the catapult
     
  2. Wendy

    Moderator

    Mar 24, 2008
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    The lenses are made of bullet proof glass, AKA lexan.

    You are looking at safety glasses, which should be worn when machining or using power tools.

    Going for the mad scientist look?
     
  3. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
    21
    What's mad scientist looK? O_O I'm not mad.
     
  4. Wendy

    Moderator

    Mar 24, 2008
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    You're young, things change. :D
     
  5. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
    21
    Um, give me one thing that changes. :DDDD
     
  6. Wendy

    Moderator

    Mar 24, 2008
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    Your voice.
     
  7. someonesdad

    Senior Member

    Jul 7, 2009
    1,585
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    Polycarbonate is not "bullet-proof glass" -- that's a different animal. Polycarbonate is a type of plastic, typically clear. It's a great material because of its impact resistance and toughness, especially compared to acrylic like Plexiglas. You'll commonly see trade names used to identify the plastic, such as Lexan for polycarbonate. I like to use it for router fixtures in the shop, as it's much more scratch resistant than acrylic and much harder to break. It makes great safety glasses, both to protect against impacts and I've found by measurements that it's a good attenuator of UV, so I also use it for working around UV sources.
     
  8. Wendy

    Moderator

    Mar 24, 2008
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    I have quite a bit of experience with Lexan. To quote Wikipedia,

    http://en.wikipedia.org/wiki/Lexan

    It is used in combat robotics, such as Battlebots, for the panels of the arena.

    A quote from your article points out ...



    Now where does the bulletproofing come from?

    An interesting property, when the Lexan was penetrated, it did not crack, it melted.
     
    Last edited: Aug 28, 2011
  9. KJ6EAD

    Senior Member

    Apr 30, 2011
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    When a safety glass or goggle is marked unbreakable, that's marketing language that means it meets the requirements of the latest version of ANSI Z87.1.
     
  10. debjit625

    Well-Known Member

    Apr 17, 2010
    790
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    I don't know much but, my glasses are made up of polycarbonate (as per the manufacturer) which is really unbreakable to some extend. It has fallen down so many times but it didn't got any scratch on it.I am sure if I use a hammer it will break but I think it will not break like a glass.

    My glasses also have some sort of protective stuff for monitor,TV screens(UV protection may be) so when I see any reflection of any object on my glasses its color changes to green or violet but I am sure it is not related to polycarbonate.
     
  11. Markd77

    Senior Member

    Sep 7, 2009
    2,803
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    The resistance of bulletproof glass comes from the lamination of glass and polycorbonate. Glass is very strong in compression, even when shattered, and the polycarbonate holds everything together. I think the glass shattering absorbs some of the energy as well.
     
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