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Old 03-19-2016, 06:52 PM   #1
Michael Thayne
 
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Default [Pyramid #3/85] Ballistic Polymer

So... what's with the ballistic polymer in the cutting-edge armor design article? Improved ballistic polymer, in particular, has half the weight modifier and nearly twice the DR per inch of improved kevlar. Is this realistic? Where are these fibers used in real life? If it is realistic, why aren't they used more widely?
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Old 03-19-2016, 07:07 PM   #2
DouglasCole
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Default Re: [Pyramid #3/85] Ballistic Polymer

Quote:
Originally Posted by Michael Thayne View Post
So... what's with the ballistic polymer in the cutting-edge armor design article? Improved ballistic polymer, in particular, has half the weight modifier and nearly twice the DR per inch of improved kevlar. Is this realistic? Where are these fibers used in real life? If it is realistic, why aren't they used more widely?
I'd guess advanced polyethylene builds . . .whatever spectra has morphed into.
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Old 03-19-2016, 08:35 PM   #3
chandley
 
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Default Re: [Pyramid #3/85] Ballistic Polymer

Yeah, all the new fibers. Dyneera, Spectra Plus, there is even a new Kevlar branded one. Been some big advances in the last few years.
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Old 03-19-2016, 09:03 PM   #4
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Default Re: [Pyramid #3/85] Ballistic Polymer

For those who don't know, Spectra and Dyneema are trade names for ultra-high molecular weight polyethylene (UHMWPE). It is a wonderful substance.
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Old 03-20-2016, 03:39 AM   #5
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Default Re: [Pyramid #3/85] Ballistic Polymer

In any case, I suspect it's just a problem with representing level III polymer armors. Last I checked, the new fibers were better than kevlar, but not factor of 2.
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Old 03-21-2016, 07:44 AM   #6
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Default Re: [Pyramid #3/85] Ballistic Polymer

Wikipedia notes that Dyneema and similar are around 40% stronger than aramid fibers. That would be consistent with a comparison between Ballistic Polymer and Improved Kevlar in the article (which is actually a 33.3% improvement), and we see a similar absolute jump between Kevlar and Improved Kevlar (-0.02) as between Ballistic Polymer and Improved Ballistic Polymer (-0.02), so the last may be a theoretical "Hey, we were able to make Kevlar better, we could probably do something similar with Dyneema, right?" Note we aren't out of TL8 yet, so designating some not-available-yet tech as TL8 isn't inappropriate (notably, the FN SCAR was still being developed when High Tech came out, but still got the TL8 designation).

Note, of course, that Ballistic Polymer and Improved Ballistic Polymer are actually better than Kevlar and Improved Kevlar in more ways than just their listed WM and DR/in. Against damage other than pi and cut, the ballistic polymers use a smaller divisor for DR - Kevlar uses a divisor of 4, Improved Kevlar a divisor of 3, and both ballistic polymers use a divisor of 2.5. In other words, their "true" WM's are 0.4, 0.32, 0.15, and 0.1. Additionally, their prices per DR are so close there's little reason not to use the ballistic polymers if they're available - for DR 1 full suits, Kevlar is $170.80/$683.20 (first number for pi/cut), Improved Kevlar is $204.96/$614.88, Ballistic Polymer is $256.20/$640.50, and Improved Ballistic Polymer is $213.50/$533.75 (yes, Improved Ballistic Polymer is both lighter and cheaper than Ballistic Polymer).
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