Talk:Polytetrafluoroethylene

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[edit] DO NOT REDIRECT Teflon here

As DuPont now uses the trademark Teflon for many products, not just Polytetrafluoroethylene (PTFE), that page should not redirect here. However, it should be changed to a disambiguation page.66.10.94.39 18:12, 11 September 2007 (UTC)

[edit] Two Teflons

"Teflon is the plastic with the lowest coefficient of friction. It is also used as a non-stick coating for pans and other cookware. Teflon is very unreactive, and so is often used in containers and pipework for reactive chemicals." -- yes, but given there are at least two teflons, which one? - - Tarquin

I think the above is for the traditional PTFE Teflon, which is called Teflon-TFE when it's needed to distinguish it from Teflon-PFA, the perfluoroalkoxy- version, which is a more recent development although it's been around too for a few years. Both Teflon-TFE and Teflon-PFA have quite similar properties and in many applications, either one can be used. My experience has been that Teflon-PFA is a bit more flexible and a bit more translucent. Teflon-TFE is the best and used for most applications, but Teflon-PFA is used for chemically inert plastic bottles. H Padleckas 22:35, 31 Oct 2004 (UTC)

Should we split off the two chemicals to articles with the full chemical name as title, leaving this article to point to them? -- Tarquin

I don't think there's that much to write about each one separately. Let's just keep this one article and mention both in here. H Padleckas 22:35, 31 Oct 2004 (UTC)

Hmm. It might be nice to mention what the teflon-application was in the space program... Was it something to do with the spacesuits? Should there be some mention of Gore-Tex® as well? questions... -- Cimon Avaro on a pogo-stick 04:14, Sep 11, 2003 (UTC)

I agree there should be some mention of Gore-Tex®. Gore-Tex® is Teflon with microscopically-sized holes through it which let gas pass through, but not liquid water. H Padleckas 22:35, 31 Oct 2004 (UTC)

Teflon insulated wire has been used in rockets and space vehicles for a long time. The excellent insulating properties and wear resistance as well as high temperature capabilities make it an excellent choice for those applications.

It can still be cut or abraded or melted if it comes in contact with something hot enough. Damaged teflon insulation was suspected as the primary cause of the Apollo 1 Command Module fire.

[edit] Teflon bullets

Can someone go into the use of Teflon in armor-piercing bullets? Kent Wang 09:58, 4 Mar 2004 (UTC)

[edit] Non stick

The article doesn't tell me why it's so non-sticky. Can anyone add that sort of layman detail? --[[User:Bodnotbod|bodnotbod » .....TALKQuietly)]] 19:18, Oct 13, 2004 (UTC)

Sure. Teflon is nonsticky because it has a very tight packed geometry. Like high thread-count sheets being smoother than low thread-count sheets, as the atoms which compose a substance are drawn closer together, the surface of the substance becomes "smoother". This smoothness is further increased by Teflon being inert and non-polar as well; meaning it doesn't "grab" at other chemicals and has full and stable electron geometries.

Non-stick redirects here. But some non-stick coatings are silicone-based (more for bakeware than stovetop applications), not fluorocarbon. --Jeff Worthington 23:54, 27 October 2006 (UTC)

Tightly packed structure is important- fluorine is somewhat larger than hydrogen and therefore the underlying electrons are not available for interaction (cause for friction). Also the final processing is important- Ck.mitra (talk) 08:24, 9 October 2008 (UTC)

non-polar also implies a high surface energy which in turn leads to non-stick. --Schwalbe 15:45, 30 October 2006 (UTC)

[edit] Teflon pan dangers

Much is said about the (sic) dangers of over heating teflon pans. Is the risk only during over-heating ... or is it believed that an over-heated pan has permanently altered such that it remains a risk in future use (even if not over-heated during subsequent use)?

[edit] Is Tephlon Cookware dangerous to humans?

I have heard that if you scrap a teflon frying pan with a metal object to stir the food while cooking the teflon can get into the food. This seems to make sense, but is that dangerous to humans at all? Thanks.

By definition, Teflon is inert. So long has it has not begun decomposition (studies suggest that sustained temperatures of over 260°C are necessary, and that the products generally evaporate away) all you will get in the food is PTFE - just about the least reactive compound known to man. So, to summarise, No. Adqam 16:48, 12 February 2006 (UTC)

Well, a cooking pan may reach 260°C if left on the fire, and evaporating composts can be inhaled. Scratching the teflon should be safe, but your frying pan would lose its non-sticking property. StefanoC 11:37, 17 February 2006 (UTC)

I have added a sentence to the safety section linking to a page on the FDA's website detailing how the toxic products of oil breakdown are more toxic than those of teflon at a similar temperature. Adqam 01:50, 20 March 2006 (UTC)

Sure, maybe teflon-derived vapors aren't dangerous, but it seems the question of whether teflon flakes are safe hasn't been answered yet. Teflon may be inert at high temperatures, but what about in the presence of stomach acid and digestive enzymes? If I'm frying some eggs, and I notice the eggs are flecked with bits of teflon that have scraped off the bottom of my pan, should I throw the eggs and the pan in the trash? MrPMonday 21:18, 14 March 2007 (UTC)

The flakes are perfectly safe to eat. It will simply move through your digestive system and be released naturally. It has not been shown to bio-accumulate. 72.72.7.210 19:37, 11 May 2007 (UTC)

[edit] How does Teflon react to UV?

I'm going to use a Teflon-tube as a secondary layer of insulation on a wire, but it is in a high-UV application. Will this cause a weardown of the specifications of the Teflon? If so, what will change?

Kent Paulsen

[edit] multi-linked polytetrafluoroethylene

I have changed

«Teflon is [[polymerization|poly]]tetra[[fluoride|fluoro]][[ethylene ]] (PTFE).»

(which renders as «Teflon is polytetrafluoroethylene (PTFE).»)

to this

«Teflon is polytetrafluoroethylene (PTFE). A [[polymerization]] of [[fluoride]] and [[ethylene]].»

(which renders as «Teflon is polytetrafluoroethylene (PTFE). A polymerization of fluoride and ethylene.»

User:H Padleckas, reverted it with a summary of RV last edit for correctness. I was never good at chemistry, so I accept that my sentence was most likely to be incorrect. But I still think that the current format is rather confusing for the reader. So I would appreciate if someone would write a correct sentence, avoiding the use of 3 links in the same word.--Nabla 22:31, 2005 Jun 6 (UTC)

I've tried to make more sense of the sentence. The problem is that while there are no fluoride ions in either the monomer tetrafluoroethylene (or tetrafluoroethene) or the polymer polytetrafluoroethylene (or polytetrafluoroethene), the alternative name ethylene tetrafluoride could be used in older chemical nomenclature. In IUPAC nomenclature, the prefix form fluoro- is preferred to avoid confusion. Note also that the fluorine atoms are present even in the monomer, substituting the hydrogen atoms in ordinary ethylene. 130.238.5.5 14:39, 13 October 2005 (UTC)

[edit] Cop Killing

I've heard it alleged (for example in Uncle Fester (author)'s Vest Busters: How to Make your Own Body-Armor-Piercing Bullets.) that aside from protecting the rifling, the teflon coating of an AP bullet reduces the friction between it and the fibres of a kevlar vest, allowing it to penetrate more kevlar before being stopped. Anyone knowledgable in such matters care to comment?

Teflon coating serves as a lubricant to reduce the wear of the barrel. Its terminal ballistics effects are negligible. The armor piercing bullet works just as a KE-penetrator, with its properties determined by small loss of energy on impact by deformation (as it is very hard), good transfer of energy into the target (pointed tip), and high kinetic energy (as it is heavy and E_k=mv²). See here: http://www.alphadogweb.com/firearms/copkillerbullets.htm --Shaddack 20:57, 17 July 2005 (UTC)

[edit] Teflon-FEP

From the article:

. Its melting point varies between 260 °C (FEP) and 327 °C (PTFE), depending on which specific Teflon polymer is being discussed.

What's FEP supposed to be? Thanks, --Abdull 15:55, 17 July 2005 (UTC)

Teflon-FEP is another type of Teflon sold by DuPont.
The FEP stands for Fluorinated Ethylene-Propylene. A Teflon-FEP molecule is a copolymer of perfluorinated ethylene and perfluorinated propylene, where all the hydrogens in the ethylene and propylene monomers are replaced by fluorine. H Padleckas 17:51, 17 July 2005 (UTC)

[edit] airsoft uses for teflon

[edit] Apparent contradiction - does teflon wear better than UHMWPE?

The article states "it is comparable with UHMWPE, where teflon displays lower resistance to wear than UHMWPE." Yet the UHMWPE article says "UHMWPE has better abrasion resistance than teflon." Which is it? ··gracefool |☺ 23:10, 3 September 2005 (UTC)

Given that resistance to wear is another name for abrasion resistance, both statements say the same - first that teflon can resist wear less well than UHMWPE, the second that UHMWPE resists wear better than teflon. --Shaddack 13:25, 6 September 2005 (UTC)

Ah right. I find "lower resistance to wear" confusing - I've changed it to a friendlier wording "although UHMWPE resists wear better than teflon". ··gracefool |☺ 12:41, 23 September 2005 (UTC)

[edit] Pravin Choksi

Mr. Pravin Choksi was the pioneer of the teflon industry in India. He established the Plastic Products Engineering Co. in November 1967 and truly revolutionised the industry.

I removed this paragraph from Toxicity because I could not find any sources for this claim, and because it was misplaced there. If you object, please comment first.

--Matthias Bauer 23:04, 8 November 2005 (UTC)

[edit] January 2006 DuPont Announcement

I've added the main points from this announcement from DuPont: Government Moves to Curb Use of Chemical in Teflon There is what appears to me to be a major contradiction in this news story, however. As I read it, DuPont has agreed to reduce "practically eliminate" factory emissions of the chemical during manufacture of Teflon. A government rep then goes on to say "This program calls on virtually eliminating those uses in those products and substituting with other materials that aren't displaying any levels of concern," This is obviously NOT the same thing. Reducing factory emissions during manufacture is NOT the same as stopping using it in products. The article does not make clear whether there are in fact TWO parts to the agreement that would cover both explanations, or whether there's only ONE agreement that has been misrepresented in the statement by the govt. official. For this reason, I have left out any suggestion that Teflons use in products will be stopped, until more clear info on this agreement becomes available. Jafafa Hots 13:17, 26 January 2006 (UTC)

Oh, one other thing.... the use of the words "new emissions" in the announcement seems to leave some serious wiggle room - it could conceivably mean that DuPont has merely agreed not to INCREASE emissions... If someone could get their hands on a copy of this agreement that would be great. Jafafa Hots 13:21, 26 January 2006 (UTC)

[edit] Can I get some feedback here?

Someone made some changes to the article section I added about the January 2006 announcement. Specifically, they changed the words "practially eliminate" (which was a direct quote of a DuPont official) to just eliminate, which has a different meaning. They also added other text which significantly changed the meaning of the supposed statements by DuPont, but while I had given a link to the news article with the quotes and info as I gave it, the only link this person provided was to a PR site of the Society for the Plastics Industry. In addition this person added some text stating that people "should feel safe" about teflon use... definitely not NPOV - this article should not be telling people to feel either unsafe or safe. Frankly, given the very POV nature of their edits, added text, and the link they provided, I suspect that the person who added this was an industry shill. (For the record, I am not anti-teflon, and I have and use teflon cookware)

I would revert these changes, but I am not sure that there wasn't SOME useful info in what they added, and anyway I'm just plain discouraged. Jafafa Hots 06:54, 7 February 2006 (UTC)

[edit] Teflon toxicity in animals

For the last eight years,I have been breeding fancy mice. During these eight years, I have noticed that my mice are very prone to cancers. I have eliminated 99.9% of these cancers by removing a couple of dietary ingredients. My question is simply,are rodents sensitive to the by-products of the breakdown of Teflon as used in the home kitchen.

No, Teflon is inert. If the pan is left at an extremely high temperature though, then it begins to decompose, which is not good.

As long as you pay attention when you're cooking for the mice and don't let the pan/oil overheat, it should be fine. 65.41.47.6 20:50, 27 April 2006 (UTC)

[edit] metric/english

Is it just me, or is there too much mixing of metric and english units in this article? Pounds, tons, celsius, farenheit? Shouldn't everything in wikipedia be metric?

That's exactly what I was thinking... Metric or English; pick one, and be consistant with it!  :-) MyrddinEmrys 02:16, 24 May 2006 (UTC)

Isn't science in general only to be used metric(World Standards)? I think so be NASA went metric direction because it cost him lots of moneys with damage missions. Andreas, Sweden :)

[edit] Removed Text

I removed the text below from the SAFETY section, but it seems to have no bearing on safety... or anything else at all. I leave it here in case someone wants to put it back somewhere better. --Mdwyer 21:46, 2 October 2006 (UTC)

When PTFE coated stir bars are exposed to a solution of solvated electrons in liquid ammonia the surface is converted to carbon.

[edit] Coefficient of Kinetic friction

The coefficient of kinetic friction of Teflon on Teflon is .04 (synovial joints in humans is .003).

This seems interesting. Should it be true, I think it ought to be in the article. Lcament 21:13, 10 October 2006 (UTC)

[edit] (R) ?

Is it really necessary to use (R) here? We don't do this with other registered products; and, moreover, Teflon is among the most generalized ones. CP/M ^comm |Wikipedia Neutrality Project| 11:41, 12 November 2006 (UTC)

Removed per Wikipedia:Manual of Style (trademarks). Femto 14:39, 12 November 2006 (UTC)

[edit] how do they get it to stick to pans

if it isn't verry sticky how do they get it so stick to things like pans?

First they make the metal surface of the pan very rough, covered in tiny scratches, dents and spiky bits. Then they spray a thin layer of teflon onto the rough surface - the teflon fits into all the tiny grooves. It is then baked for a while to make the PTFE set. Further layers of teflon can then be sprayed on.

Ben 14:11, 26 November 2006 (UTC)

Why the pan looks black whereas regular teflon is milky white? Just pondering... Ck.mitra (talk) 08:24, 9 October 2008 (UTC)

[edit] CHEMBOX????

This article would really benefit from a chembox - I am surprised it doesn't have one, given the importance (and unique properties) of PTFE. 209.244.31.53 21:21, 31 March 2007 (UTC)

[edit] Removed link to tuberose.com. There's a lot of wiggle room.

I removed the citation to tuberose.com/Teflon.html. While I think it might make a good starting place, bits like "chunks of PTFE are jagged, scary-looking chunks of synthetic chemicals that have no place in the human body. You really don’t want to eat this. Imagine what a metal spatula might do after scrambling eggs, flipping burgers or stir-frying some vegetables" cause me to lean toward considering this a bit unreliable; appeals to "it looks scary!" on a site which is selling alternative-medicine products aren't the most convincing. There's a lot of assertions about the dangers of Teflon pots and pans, but unfortunately everything is either funded by DuPont or written by folks like the above. There's the EPA report, which is good, but it's not final, and I'm just disappointed that despite plenty of news coverage and marketing flim-flam, reliable facts seem to be in such short supply. grendel|khan 21:21, 12 June 2007 (UTC)

[edit] Lowest coefficient of friction?

According to the Guinness World Records, Hi-T-Lube sliding against itself has a coefficient of friction of only 0.03 (and it is definitely a solid material). If this is the case, then it is incorrect to say that Teflon has the lowest coefficient of friction (which is stated above as 0.04). Bbi5291 21:08, 31 July 2007 (UTC)

[edit] Brand name

Teflon® is a registered brandname of E.I DuPont company. Shouldn't it be recognised as such, and not be redirected to PTFE?

DuPont sells at least 3 materials (TFE, PFA, FEP) under the Teflon® Brandname —The preceding unsigned comment was added by Sahilbablani (talk • contribs) 20:34, August 20, 2007 (UTC).

The products are similar enough that they overlap to a degree where separate articles may not be warranted. I've tagged the other articles you created on this subject. Please read over Wikipedia's guidelines on products and brand dnames before reverting these again. Chris Cunningham 23:53, 20 August 2007 (UTC)

[edit] Teflon in most Americans blood

Conclusive studies have proven that the substance commonly known as Teflon is in the bloodstream of most Americans. They have known this conclusively for about a year now. From what I have read it is not known how it got into peoples blood, and it is not known if it will hurt peoples babies. One of the many sources are here [[1]] and the medical journals are also online and capable of being sourced to. I don't know why this isn't in the article, Polytetrafluoroethylene in peoples blood is about as most relevent to humans as it can get. And humans are Wikipedias primary audience. JayKeaton 14:31, 8 October 2007 (UTC)

It is not Teflon, but perfluorooctanoic acid (PFOA), a substance used in Teflon processing. The article on PFOA has some information about the health concerns. This article (the one on polytetrafluoroethylene) already mentions PFOA (under "Carcinogens in production") and links to the relevant article. --Itub 09:45, 10 October 2007 (UTC)

The CBS article is light on the facts, but even it doesn't match up to the claims you're making. As Itub pointed out, it's not PTFE but PFOA, and it's not "in most Americans blood" but rather in the cord blood of a sample of newborns. (The headline at CBS gets the distinction between PTFE and PFOA wrong, contradicting the article there.) grendel|khan 14:04, 11 May 2008 (UTC)

[edit] Citation needed on K416

Gaseous diffusion plant in Tennessee is known as K-25. Reference cited does not appear to have any reference or information pertaining to the gaseous diffusion plant being being known as K416, or anything pertaining to gaseous diffusion at all. Cited reference is about gore-tex material which seems to have essentially nothing to do with uranium enrichment at all. For reference, K25 wiki page: http://en.wikipedia.org/description/K-25 where it is specifically cited as the gaseous diffusion plant.

As84kda (talk) 17:21, 13 April 2008 (UTC)

You are correct. When I first read it I thought that it meant that Teflon used to be called K416, but upon a more rigorous google search all of the references to teflon named K416 actually come from the wikipedia article. I do believe you are correct that it should be K-25, however I think it should be reworded so that it's clear that K-25 refers to the plant and not the material. --Wizard191 (talk) 19:23, 13 April 2008 (UTC)