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Author Topic: How do non-stick coatings work, and how are they attached to the surface?  (Read 8995 times)

Offline neilep

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Dear Panologists,


see my pans ?



Nice eh ?...notice that despite not actually cooking anything they are not sticking to each other !!


What i'd like to know is....what is the non stick stuff ?.....and how does the non-stick stuff stick to the pan !


I really don't know.....I hope I do soon !!


hugs

Neil
xxx


« Last Edit: 04/03/2008 23:37:09 by chris »


 

Offline Karen W.

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I believe it is spray I am not sure if it is still Teflon! Though I will have to check the sprays have changed over the years and the newer material seems to be tougher.

 Used to be cooking in teflon would kill your pet birds.. with the fumes... made me worry about myself!

I believe it is some form of polymers! Here is the process!

http://www.madehow.com/Volume-7/Teflon.html

Nonstick cookware

    * 7 One of the most common and visible uses of PTFE is coating for nonstick pots and pans. The pan must be made of aluminum or an aluminum alloy. The pan surface has to be specially prepared to receive the PTFE. First, the pan is washed with detergent and rinsed with water, to remove all grease. Then the pan is dipped in a warm bath of hydrochloric acid in a process called etching. Etching roughens the surface of the metal. Then the pan is rinsed with water and dipped again in nitric acid. Finally it is washed again with deionized water and thoroughly dried.
    * 8 Now the pan is ready for coating with PTFE dispersion. The liquid coating may be sprayed or rolled on. The coating is usually applied in several layers, and may begin with a primer. The exact makeup of the primer is a proprietary secret held by the manufacturers. After the primer is applied, the pan is dried for a few minutes, usually in a convection oven. Then the next two layers are applied, without a drying period in between. After all the coating is applied, the pan is dried in an oven and then sintered. Sintering is the slow heating that is also used to finish the billet. So typically, the oven has two zones. In the first zone, the pan is heated slowly to a temperature that will evaporate the water in the coating. After the water has evaporated, the pan moves into a hotter zone, which sinters the pan at around 800F (425C) for about five minutes. This gels the PTFE. Then the pan is allowed to cool. After cooling, it is ready for any final assembly steps, and packaging and shipping.

Byproducts/Waste

Though PTFE itself is non-toxic, its manufacture produces toxic byproducts. These include hydrofluoric acid and carbon dioxide. Work areas must be adequately ventilated to prevent exposure to gases while PTFE is being heated, or when it cools after sintering. Doctors have documented a particular illness called polymer fume fever suffered by workers who have inhaled the gaseous byproducts of PTFE manufacturing. Workers must also be protected from breathing in PTFE dust when PTFE parts are tooled.

Some waste created during the manufacturing process can be reused. Because PTFE was at first very expensive to produce, manufacturers had high incentive to find ways to use scrap material. Waste or debris generated in the manufacturing process can be cleaned and made into fine powder. This powder can be used for molding, or as an additive to certain lubricants, oils, and inks.

Used PTFE parts should be buried in landfills, not incinerated, because burning at high temperatures will release hydrogen chloride and other toxic substances. One study released in 2001 claimed that PTFE also degrades in the environment into one substance that is toxic to plants. This is trifluoroacetate, or TFA. While current levels of TFA in the environment are low, the substance persists for a long time. So TFA pollution is possibly a concern for the future.
« Last Edit: 18/02/2008 21:22:33 by Karen W. »
 

Offline Carolyn

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Used to be cooking in teflon would kill your pet birds.. with the fumes... made me worry about myself!

Sorry Neil....just have to drift off topic for a second.

KAREN!  THANK YOU!!! 

Finally a solution to my bird problem!  No more firecrackers, rubber snakes, loud music, etc.....

I just need to have a big ole' Teflon cookout! ;D

YES!!!  I think I'll plan one for this weekend!
 

Offline Karen W.

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LOL...LOL.. Thats funny! Poor whittle birdies.....


Carolyns Killing our whittle birdies!!!! OH NO!!!!!! LOL!
 

Offline DoctorBeaver

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Evil, cruel woman!
 

Offline Karen W.

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LOL LOL LOL....
 

Offline Carolyn

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Evil, cruel woman!

Yes I am....but I'm a lot of fun! ;)
 

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