Talk:Ultra-high-molecular-weight polyethylene

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Latest comment: 1 month ago by 119.224.26.241 in topic Annealing?

Toxicity

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question re. toxicity...word "Ptex" redirects here, skiers & technicians often light ptex on fire and drip into gouges (mentioned in ski section of this page) are not the resulting fumes toxic? Perhaps some more detail about toxicity. Rickbolger (talk) 16:34, 8 May 2009 (UTC)Reply

Good point. Material safety data sheets normally have a separate toxicity section for combustion products. Worth checking. Pure polyethylene burns fairly cleanly to CO2 and H2O, but there could still be a carbon monoxide hazard if the oxygen supply was insufficient for complete combustion. I won't speculate on the effect of additives in Ptex.LeadSongDog come howl 17:28, 8 May 2009 (UTC)Reply

ISS Crew Quarters

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I am not a chemist, but would appreciate someone with knowledge of the subject integrating this reference: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080013462_2008012884.pdf into the article. It indicates (page 3) the majority of the back wall of each of the International Space Station crew quarters are made of UHMWPE, "which provides shielding of the crewmember’s head and blood forming organs from the ever-present cosmic radiation and occasional solar flares." Does UHMWPE really do this better than other polyethylenes? Thanks! (sdsds - talk) 00:12, 25 December 2012 (UTC)Reply

20 times stronger than steel?

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It says 15 times stronger than steel in the article. On the National Geographic Channel there is a program called Doomsday Preppers, and season 2 episode 14 says its 20 times stronger than steel. Any scientific publications out there show the exact amount? Dream Focus 15:23, 23 February 2013 (UTC)Reply

xxx times stronger than steel is always dubious, because steel is a family of materials with vastly different properties. Also, hardness measurements are not that accurate. Materialscientist (talk) 23:53, 23 February 2013 (UTC)Reply

Annealing?

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The exact procedure to anneal the material is described, but not the REASON for, or effects of, annealing it. Does annealing apply to all forms & types? Is it a common practice by any of the producers noted? Steve8394 (talk) 04:53, 24 April 2015 (UTC) excellent question, why anneal it? What happens to it? Anyone else got the answer? — Preceding unsigned comment added by 213.121.165.36 (talk) 19:06, 1 August 2015 (UTC)Reply

https://patents.google.com/patent/EP2921186A1/en
- radiation causes free radicals
- annealing in the absence of oxygen causes free radicals to move around and cause present crosslinking
- oxygen plus free radicals cause chemical damage (chain breakage), rather than crosslinking
- controlled cooling causes crystalization
- crosslinking and crystalization cause stiffness, stretching (yield) strength, impact resistance, wear resistance, and creep resistance
Everything that I know on this subject, I learned from reading this patent.
119.224.26.241 (talk) 09:07, 16 October 2024 (UTC)Reply

Dyneema, Spectra and oriented polymers?

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Dyneema and Spectra are described here (as I'd always understood them to be) as "oriented-strand". This is how how they develop their remarkable strength, and why it's only the case for spun fibres rather than bulk materials. However the rest of the section then discusses "UHMWPE fibers" with no distinction being made.

Are all UHMW spun fibres oriented like this, and thus equally strong? Or are there "generic fibres" and "oriented fibres", of different strengths? Andy Dingley (talk) 20:07, 4 August 2015 (UTC)Reply


The Wire/Cable Section needs a rewrite or deletion

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First, the wire/cable section is almost a verbatim copy/paste from the citation (http://www.performancewire.com/product/halar/). Second, the section is actually a description of "HALAR" cable, which is not defined anywhere in the citation. A little more digging finds this page: http://toefco.com/what-is-halar-coating/: that reveals that HALAR is actually a brand name for a specific type of cable coating used to impart strength and chemical/electrical/temperature resistance to UHMWPE cables. Given that this section looks at best like mistaken information, and at worse looks like a possible copyright violation, it needs deletion or a major rewrite. — Preceding unsigned comment added by Bgovern (talkcontribs) 07:15, 17 July 2016 (UTC)Reply

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Dyneema Strength not Comparable to Steel

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Hello,

The first paragraph in the applications section notes that the Dyneema and Spectra products have a strength which is comparable to high strength steel. This is an overstatement since, if in reference to:

SAE High-Strength Low-Alloy (HSLA), or ASTM A490 (High strength structural bolts)

which have specified minimum yield stresses of about 80,000-psi and 130,000-psi, respectively.

Of course, these are minimum design strengths (in reality these yield stresses will be significantly higher), it is certainly still not comparable to the yield stress of 350,000-psi given here. The SAE and ASTM standard specs are not modest forms of steel. To my knowledge, A490 bolts are among the strongest forms of high-strength steel, and are applied for structural anchoring purposes.

But it is certainly not comparable to 350,000-psi, that kind of strength is a whole different ball game.


Crswong888 (talk) 11:01, 17 May 2018 (UTC)Reply
Well, SAE 6150 reaches 175ksi, but there are Bainite steels that do much better: see https://doi.org/10.1016/j.jallcom.2017.02.164 or http://www.phase-trans.msm.cam.ac.uk/2010/nano.html for examples. LeadSongDog come howl! 17:50, 17 May 2018 (UTC)Reply

A Commons file used on this page has been nominated for deletion

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The following Wikimedia Commons file used on this page has been nominated for deletion:

Participate in the deletion discussion at the nomination page. —Community Tech bot (talk) 15:52, 12 October 2018 (UTC)Reply

Ice rinks

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A notable use is in unrefrigerated ice rinks, if anyone cares to dig up a WP-approved source. 73.4.237.111 (talk) 22:41, 13 August 2024 (UTC)Reply