Talk:Dyneema

Wetting[edit]

This is a tough one: in the "Properties" section, my original language said something general about "poor wetting", which I mainly meant to refer to wetting of resin in a composite layup. Unfortunately, this was a very clunky way to get this concept across. A series of cosmetic fixes has led us to the current language, which says "does not get wet easliy". "Get wet" almost universally refers to water, which mostly misses the point. Any ideas on how to fix this?--Joel 02:09, 25 Jun 2005 (UTC)

UHMWPE at last[edit]

The big changes recently are due to the advent of a more general article on the material from which these fibers are made. I recommend you check it out!--Joel 30 June 2005 00:35 (UTC)

Olefin?[edit]

The polymer material is called an olefin in the article. But, if it is indeed based on polyethylene, it has to be a paraffin [alkane], since polyethylene does not have unsaturated chemical bonds. Nevertheless, having no knowledge of this particular material, I chose to abstain from editing the article right away, waiting instead for an expert to intervene.

Production?[edit]

I am concerned with the production section. Olefins are generally highly resistant to solvents, yet the production section says that Dyneema is is drawn into fibers as the solvent evaporates. My guess is that the fibers are drawn as the PE polymerizes. Can anyone find a citation? I will search for something myself as well.

Also, to the anonymous user above questioning the use of "olefin". In terms of organic chemistry, you are correct, but in the plastics industry, it is common to call anything in the PE or PP family an olefin. --Gbutler77 05:59, 11 February 2006 (UTC)[reply]

OK, I did a little research. Dyneema is made by "Gel Spiining" (see http://www.fibersource.com/f-tutor/techpag.htm).

Can we add any information or pictures from the site? I'm brand new to Wikipedia, so I am still learning what can be done.--Sonic 06:25, 11 February 2006 (UTC)[reply]

I changed the production section. Let me know if you want me to change anything. --Sonic 06:54, 11 February 2006 (UTC)[reply]

Dyneema vs. Spectra[edit]

Dyneema is not the same thing as Spectra. Dyneema is a brand name product made by DSM. Spectra is a brand name product made by Honeywell. They are both examples of PE fiber, but are competing products. Kevlar is also a brand name product made by DuPont, but is an aramid. Just opening up the discussion since the Dyneema page says, "Dyneema or Spectra." —Preceding unsigned comment added by 2006sf (talk • contribs)

As far as the article is written now, the article is about the material, not the brand name. Assuming that they are, in fact, the same material, then they should be in the same article. (Wikipedia doesn't generally have articles about brand names and usually uses the generic name—there just doesn't seem to be a generic name for this material). If the article is wrong and they are actually different materials, then they should be in separate articles. Can you provide some references to clarify this? — Saxifrage ✎ 21:41, 10 October 2006 (UTC)[reply]

Here are some technical differences from the book "High-Performance Fibers". In any event the article is wrong in my opinion on two counts (1) It promotes and is about a brand name and (2) Is factually incorrect since it implies/states that Dyneema is somehow "the technology", when in fact, UHMWPE is the technology, examples of which are Spectra and Dyneema and others....

Thanks,

	Dyneema® fiber	Spectra® fiber
Process	Gel Spinning	Gel Spinning
Fiber density (kg/m²)	970	970
Fiber denier/fil*	1-2 dpf	3.5-10 dpf
Tenacity (N/tex)*	2.8-3.7	2.6-3.4
Modulus (N/tex)*	91-122	75-120
Elongation (%)*	3.5-3.8	2.9-3.6

* Source “High-Performance Fibers” book edited by J.W.S.Hearle, Woodhead Publishing Ltd, Page 69, 2001

Sorry. I don't know how to organize the chart here... —Preceding unsigned comment added by 2006sf (talk • contribs)

Any reading of this article that says Dyneema is somehow "the technology" is reading too much into the title. In fact, the article clearly says, "Though the production details will undoubtedly be different, the resulting materials are comparable. This article refers to both materials by the name Dyneema." If there is no generic name, this is an acceptable way to treat the material.

Secondly, we don't have articles about different brand names of the same thing, unless those brand names are somehow relevant enough to have articles about the brand name separately from the material. Since this article is not about the brand name and is about the material, that objection just doesn't apply.

Now, with that out of the way, the question isn't settled. I can't tell from the above table whether they are differnt materials: are they? (Again, being different brands is irrelevant.) For instance, different brands of borosilicate glass are going to have slightly different properties but they're still all borosilicate glass.

A second issue is this: is there a generic name for the material? If so, this article should be renamed to whatever that is, or if it already exists, should be merged into an existing article about it. You said that both Spectra and Dyneema are UHMWPE: is that the generic name, or are they both a special kind of UHMWPE that doesn't have a name apart from Spectra/Dyneema? — Saxifrage ✎ 22:06, 11 October 2006 (UTC)[reply]

Given the lack of response, I'm changing the article back. Please address the points above if you disagree. — Saxifrage ✎ 20:41, 22 October 2006 (UTC)[reply]

The two brands in questions have some differences, but are indeed both examples of UHMWPE. All of these brand names like Kevlar and Dyneema appear to me to violate Wikipedia's policies on promoting brand names. I would suggest these materials be joined into one section of the UHMWPE article. While there are other uses of UHMWPE, as I understand, this seems like it would be the best place. A subsection of Applications of UHMWPE perhaps? BTW I am sf2006, but I could not log in under that name for some reason all of a sudden... Thanks. —Preceding unsigned comment added by Polyplas (talk • contribs)

We do have a policy against using Wikipedia for promotion, but Kevlar doesn't fall under that. Kevlar is culturally significant in the Real World due to its brand name, while Dyneema and Spectra aren't. (This is similar to the situation with Kleenex.) Thus, we have an article about UHMWPE (the general material), Kevlar (the brand and material) and an article about Spectra/Dyneema (a specific UHMWPE material?). Just so, we have Borosilicate glass (the material), Pyrex (the brand), and the articles Bomex and Kimax are being merged into Borosilicate glass.

The question is, is Spectra/Dyneema a special kind of UHMWPE? If so, it should have an article under some kind of name. If it's just UHMWPE under two brand names and isn't special, then they should be merged into UHMWPE or deleted entirely. To move forward this needs to be determined.

(Incidentally, the name you used before was 2006sf, not sf2006, so that might be why you couldn't log in. Pick either 2006sf or Polyplas to keep and abandon the other.) — Saxifrage ✎ 20:26, 1 November 2006 (UTC)[reply]

Sorry! Thanks. I will keep Polyplas. Also, I agree about Kevlar's significance. It is also an Aramid fibre and not PE fibre. For the other two UHMWPE is in my opinion the best place. I mentioned that there are other uses of UHMWPE based on that article. I would say that they are special kinds of UHMWPE and should either be in one "generically" titled article or the content moved to UHMWPE. Thanks again. —Preceding unsigned comment added by Polyplas (talk • contribs)

That sounds in line with what I've been suspecting: that neither are "special" in any way except for the gel-spinning process, which really doesn't change them that much. Unless there's a compelling reasons to have an article on Dyneema or Spectra apart from UHMWPE specifically, then this should be merged as you say. — Saxifrage ✎ 21:41, 1 November 2006 (UTC)[reply]

How does the process work next? Should I/we take the content from each article and create a new section under UHMWPE? Thanks. —Preceding unsigned comment added by Polyplas (talk • contribs)

If there's agreement here, that's half of what needs to be before we start the move. I'll post on Talk:Ultra high molecular weight polyethylene asking if there are any objections to merging in this material. Assuming there will be none, we can take the pertinent material from here and add it to that article in a couple days. I don't expect there to be a problem, but it's good to wait and see anyway, if even for only a few days. — Saxifrage ✎ 02:39, 4 November 2006 (UTC)[reply]

Great. Let's see how others on the UHMWPE article feel first. Thanks. —Preceding unsigned comment added by Polyplas (talk • contribs)

There's been no response for four days, so I'd say go ahead with it. If there are any objections after (say, if changes to the article get more attention than the message I left), then take it to the Talk page there and work it out. Be bold! (And remember to sign your posts.) — Saxifrage ✎ 20:24, 8 November 2006 (UTC)[reply]

Should I delete the Dyneema page? I don't know if the merge was technically successful. Thanks. —The preceding unsigned comment was added by Polyplas (talk • contribs) 19:22, 7 December 2006 (UTC).[reply]

I removed the merge tag from the UHMWPE article and I'm going to just change this page into a redirect to finish the merge as all the material here is now listed on the UHMWPE article. Wizard191 20:44, 17 December 2006 (UTC)[reply]