Non-stick surface: Difference between revisions
Reverted good faith edits by 75.51.144.118 (talk): It's a ceramic coating and nothing more UNLESS independent reliable sources say otherwise. (TW) |
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Non-stick coatings are also used in [[lubrication]] applications. |
Non-stick coatings are also used in [[lubrication]] applications. |
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=History= |
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The [[Mycenaeans|Mycenaean Greeks]] might have used non-stick pans to make bread more than 3,000 years ago. Mycenaean ceramic griddles had one smooth side and one side covered with tiny holes. The bread was probably placed on the side with the holes, since the dough tended to stick when cooked on the smooth side of the pan. The holes seemed to be an ancient non-sticking technology, ensuring that oil spread quite evenly over the griddle.<ref>[http://www.livescience.com/42414-ancient-cooking-mycenaeans-portable-grills.html Ancient Greeks Used Portable Grills at Their Picnics], LiveScience</ref><ref>[http://www.archaeology.org/news/1707-140109-mycenaean-souvlaki-tray How to Cook Like a Mycenaean], Archaeology Magazine</ref> |
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==Development== |
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The modern non-stick pans were made using a coating of Teflon (polytetrafluoroethylene or PTFE). PTFE was invented serendipitously by [[Roy Plunkett]]<ref>https://www.chemheritage.org/classroom/chemach/plastics/plunkett.html</ref> in 1938, while working for a joint venture of the [[DuPont]] company. The substance was found to have several unique properties, including very good corrosion resistance and the lowest coefficient of friction of any substance yet manufactured. PTFE was used first to make seals resistant to the [[uranium hexafluoride]] gas used in the [[Manhattan Project]] during [[World War II]] and was regarded as a military secret. Dupont registered the Teflon trademark in 1944 and soon began planning for post-war commercial use of the new product.<ref name="IandTmag">{{cite magazine|journal=[[Invention and Technology Magazine]]|author=Anne Cooper Funderburg|title=Making Teflon Stick|series=Summer 2000|volume=16|issue=1|url=http://www.americanheritage.com/articles/magazine/it/2000/1/2000_1_10.shtml|accessdate=2009-05-06}}</ref> |
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By 1951 Dupont had developed applications for Teflon in commercial bread and cookie-making; however the company avoided the market for consumer cookware due to potential problems associated with release of toxic gases if stove-top pans were overheated in inadequately ventilated spaces. Marc Grégoire, a French engineer, had begun coating his fishing gear with Teflon to prevent tangles. His wife Colette suggested using the same method to coat her cooking pans. The idea was successful and a French patent was granted for the process in 1954. The [[Tefal]] company was formed in 1956 to manufacture non-stick pans.<ref name="IandTmag" /> |
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Not all modern non-stick pans use Teflon; other non-stick coatings have become available. For example, a mixture of [[titanium]] and [[ceramic]] can be [[sandblasting|sandblasted]] onto the pan surface, and then [[pottery firing|fired]] to {{convert|2000|C|F}}.<ref>{{cite encyclopaedia|encyclopedia=A to Z of Inventions and Inventors: M to P|article=Non-stick pan|author=Pennie Stoyles and Peter Pentland|pages=17|publisher=Black Rabbit Books|year=2007|isbn=9781583407899}}</ref> |
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== Uses and limitations == |
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[[File:100 0783.JPG|thumb|right|Food in a non-stick pan]] |
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With other types of pans, some [[Cooking oil|oil]] or fat is required to prevent hot food from sticking to the pan's surface. Food does not have the same tendency to stick to a non-stick surface; pans can be used with less, or no, oil, and are easier to clean, as residues do not stick to the surface. |
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Utensils used with PTFE-coated pans can scratch the coating, if the utensils are harder than the coating; this can be prevented by using non-metallic (usually plastic or wood) cooking tools. |
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According to writer Tony Polombo pans that are not non-stick are better for producing pan gravy, because the [[fond]] (the caramelized drippings that stick to the pan when meat is cooked) sticks to them, and can be turned into pan gravy by [[deglazing (cooking)|deglazing]] them—dissolving them in liquid.<ref>{{cite book|title=Cooking|chapter=Pots and Pans|author=Tony Polombo|pages=20|publisher=iUniverse|year=2006|isbn=9780595378661}}</ref> |
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{{Expand section|date=December 2009}} |
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== Health concerns == |
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Concerns have been raised over the possible negative effects of using PTFE-coated cooking pans. When pans are overheated beyond approximately 350 °C (660 °F) the PTFE coating begins to dissociate, releasing byproducts (PFOA) which can cause [[polymer fume fever]] in humans and can be lethal to birds.<ref name="IandTmag" /><ref>{{cite web |url=http://www.teflon.com/Teflon/teflonissafe/keyquestions.html#q2 |archiveurl=http://web.archive.org/web/20080117234907/http://www.teflon.com/Teflon/teflonissafe/keyquestions.html#q2 |archivedate=2008-01-17 |title=Safety of Teflon Non-Stick Coatings for Cookware|publisher=[[DuPont]]|accessdate=2009-05-06}}</ref><ref>{{cite web |url=http://www.ewg.org/reports/toxicteflon|author=Jane Houlihan ''et al.''|title=EWG finds heated Teflon pans can turn toxic faster than DuPont claims |publisher=[[Environmental Working Group|EWG]]|accessdate=2009-05-06}}</ref> |
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Processing of PTFE in the past used to include [[Perfluorooctanoic acid]] (PFOA) as an emulsifier, however PFOA is a [[persistent organic pollutant]] and poses both environmental and [[PFOA#Health_concerns|health concerns]], and is now being phased out of use in PTFE processing.{{cn|date=November 2013}} |
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==PTFE and similar compounds== |
==PTFE and similar compounds== |
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==External links== |
==External links== |
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* [http://home.howstuffworks.com/nonstick-cookware.htm How non-stick pan works] |
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*[http://news.bbc.co.uk/1/hi/technology/3178136.stm "Science plans 'non-stick' submarine", ''bbc.co.uk'', 10 October, 2003] |
*[http://news.bbc.co.uk/1/hi/technology/3178136.stm "Science plans 'non-stick' submarine", ''bbc.co.uk'', 10 October, 2003] |
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*[http://news.bbc.co.uk/2/hi/science/nature/6993719.stm "'Virtually non-stick' gum created", Rebecca Morelle and Liz Seward, ''BBC News'', 13 September 2007] |
*[http://news.bbc.co.uk/2/hi/science/nature/6993719.stm "'Virtually non-stick' gum created", Rebecca Morelle and Liz Seward, ''BBC News'', 13 September 2007] |
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[[Category:Brand name materials]] |
[[Category:Brand name materials]] |
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[[Category:Materials science]] |
[[Category:Materials science]] |
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[[Category:Cookware and bakeware]] |
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Revision as of 19:09, 25 January 2014
A non-stick surface is a surface engineered to reduce the ability of other materials to stick to it. A non-stick coating may be applied to a substrate to produce such a surface. One common application of non-stick coatings is cookware. Until recently PTFE (under the brand name "Teflon") dominated this market. Other coatings, including anodized aluminium and ceramics, have become popular.
Non-stick coatings are also used in lubrication applications.
History
The Mycenaean Greeks might have used non-stick pans to make bread more than 3,000 years ago. Mycenaean ceramic griddles had one smooth side and one side covered with tiny holes. The bread was probably placed on the side with the holes, since the dough tended to stick when cooked on the smooth side of the pan. The holes seemed to be an ancient non-sticking technology, ensuring that oil spread quite evenly over the griddle.[1][2]
Development
The modern non-stick pans were made using a coating of Teflon (polytetrafluoroethylene or PTFE). PTFE was invented serendipitously by Roy Plunkett[3] in 1938, while working for a joint venture of the DuPont company. The substance was found to have several unique properties, including very good corrosion resistance and the lowest coefficient of friction of any substance yet manufactured. PTFE was used first to make seals resistant to the uranium hexafluoride gas used in the Manhattan Project during World War II and was regarded as a military secret. Dupont registered the Teflon trademark in 1944 and soon began planning for post-war commercial use of the new product.[4]
By 1951 Dupont had developed applications for Teflon in commercial bread and cookie-making; however the company avoided the market for consumer cookware due to potential problems associated with release of toxic gases if stove-top pans were overheated in inadequately ventilated spaces. Marc Grégoire, a French engineer, had begun coating his fishing gear with Teflon to prevent tangles. His wife Colette suggested using the same method to coat her cooking pans. The idea was successful and a French patent was granted for the process in 1954. The Tefal company was formed in 1956 to manufacture non-stick pans.[4]
Not all modern non-stick pans use Teflon; other non-stick coatings have become available. For example, a mixture of titanium and ceramic can be sandblasted onto the pan surface, and then fired to 2,000 °C (3,630 °F).[5]
Uses and limitations
With other types of pans, some oil or fat is required to prevent hot food from sticking to the pan's surface. Food does not have the same tendency to stick to a non-stick surface; pans can be used with less, or no, oil, and are easier to clean, as residues do not stick to the surface.
Utensils used with PTFE-coated pans can scratch the coating, if the utensils are harder than the coating; this can be prevented by using non-metallic (usually plastic or wood) cooking tools.
According to writer Tony Polombo pans that are not non-stick are better for producing pan gravy, because the fond (the caramelized drippings that stick to the pan when meat is cooked) sticks to them, and can be turned into pan gravy by deglazing them—dissolving them in liquid.[6]
![[icon]](/wiki/File:Wiki_letter_w_cropped.svg){kind=small} | This section needs expansion. You can help by adding to it. (December 2009) |
Health concerns
Concerns have been raised over the possible negative effects of using PTFE-coated cooking pans. When pans are overheated beyond approximately 350 °C (660 °F) the PTFE coating begins to dissociate, releasing byproducts (PFOA) which can cause polymer fume fever in humans and can be lethal to birds.[4][7][8]
Processing of PTFE in the past used to include Perfluorooctanoic acid (PFOA) as an emulsifier, however PFOA is a persistent organic pollutant and poses both environmental and health concerns, and is now being phased out of use in PTFE processing.[citation needed]
PTFE and similar compounds
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer used in various applications including non-stick coatings. Originally developed by a DuPont-General Motors joint venture, today it is commonly known by DuPont's brand name Teflon, though other producers exist producing PTFE compounds under various other names. At temperatures above circa 600°F (320°C), which are normally only reached when dry pans are heated, toxic fumes are given off by such coatings; these can result in flu-like symptoms in humans and cause death in birds.[9][10]
Processing of PTFE in the past used to include Perfluorooctanoic acid (PFOA) as an emulsifier, however PFOA is a persistent organic pollutant and poses both environmental and health concerns, and is now being phased out of use in PTFE processing.[citation needed]
Non-stick coating systems often include a special treatment of the substrate. For example, Whitford Corporation's Excalibur consists of three layers of PTFE over a metallic substrate which is first grit-blasted to roughen it, then electric-arc sprayed with a proprietary stainless steel alloy.[11][12] According to Whitford, the irregular surface promotes adhesion of the PTFE and also resists abrasion of the PTFE.[13]
Teflon
Teflon is a trademark of DuPont used to refer to their non-stick products. While mainly being used as a trade name for PTFE, it is also used to market Perfluoroalkoxy (PFA, as "Teflon PFA") and Fluorinated ethylene propylene (FEP, as "Teflon FEP") compounds. DuPont's current line-up of non-stick coatings for cookware is (arranged in order of decreasing price and durability): DuPont Autograph, DuPont Teflon Platinum Pro, DuPont Teflon Platinum, DuPont Teflon Select, DuPont Teflon Xtra, DuPont Teflon Classic and DuPont Teflon with Radiance Technology.[14]
Non-PTFE compounds
Non-PTFE compounds are often based on Sol-gel technologies and marketed as "ceramic coatings".
See also
- Cooking spray
- Electroless nickel plating
- LiquiGlide
- Lunac (alloy and trans-ceramic coatings)
- Non-stick pan
- Silpat
- Silverstone (plastic)
- Tefal
- Teflon (nickname)
- Thread seal tape
References
- ^ Ancient Greeks Used Portable Grills at Their Picnics, LiveScience
- ^ How to Cook Like a Mycenaean, Archaeology Magazine
- ^ https://www.chemheritage.org/classroom/chemach/plastics/plunkett.html
- ^ a b c Anne Cooper Funderburg. "Making Teflon Stick". Invention and Technology Magazine. Summer 2000. Vol. 16, no. 1. Retrieved 2009-05-06.
- ^ Pennie Stoyles and Peter Pentland (2007). "Non-stick pan". A to Z of Inventions and Inventors: M to P. Black Rabbit Books. p. 17. ISBN 9781583407899.
- ^ Tony Polombo (2006). "Pots and Pans". Cooking. iUniverse. p. 20. ISBN 9780595378661.
- ^ "Safety of Teflon Non-Stick Coatings for Cookware". DuPont. Archived from the original on 2008-01-17. Retrieved 2009-05-06.
- ^ Jane Houlihan; et al. "EWG finds heated Teflon pans can turn toxic faster than DuPont claims". EWG. Retrieved 2009-05-06.
{{cite web}}: Explicit use of et al. in:|author=(help) - ^ American Cancer Society, Teflon and Perfluorooctanoic Acid (PFOA)
- ^ Tugend, Alina (October 14, 2006). "Teflon Is Great for Politicians, but Is It Safe for Regular People?". New York Times. Retrieved 15 September 2013.
- ^ Nicholas J. Wall, US 5069937 "Thermal spraying of stainless steel", 1988
- ^ Laurence W. McKeen, Fluorinated coatings and finishes handbook, 2006, p. 117
- ^ Excalibur brochure, PDF
- ^ http://www2.dupont.com/Teflon/en_US/products/cookware_coatings/index.html