That burnt layer of cheese refusing to release from the pan. That cake stubbornly clinging to its baking tin and crumbling out in pieces (#fail). Those sad and dry remnants of fried eggs singed to your pan. Aren’t these annoying cooking hassles? They sure are for me.
One can avoid the dark despair of broken cakes and un-scrubbable burnt pans, thanks to what began as a military secret during World War II: polytetrafluoroethylene (a.k.a. PTFE or Teflon).
This plastic polymer of carbon and fluorine atoms began as a sealant in the production of the atomic bomb, but it is now part of a common household item: the non-stick pan.
Teflon’s unique physical properties give it one of the lowest coefficients of friction of any solid. If you have taken a physics class, you may recognize the following equation, which would represent the force of friction between a Telfon coated pan and an egg, for example:
Force of friction = (coefficient of friction) x (mass of egg) x (gravitational constant)
Therefore, Teflon’s low coefficient of friction equates to low friction force. Just as ice skates glide along an ice rink, an egg “glides” without much friction on a non-stick pan. Prior to the production of Teflon pans, butter or grease were the only options in eliminating this cuisine-ruining friction.
However, what does it mean to “eliminate friction.” Where’d it go? If you took a strong magnifying glass to a regular pan, you would find many ridges and valleys scraped into the pan, even if it looks and feels smooth. Similar to the interlocking nature of a zipper, an egg can become interlocked with all these ridges in the pan. Coating a pan with butter or Teflon fills in all these ridges, creating a smooth flat surface. Then, the egg can’t grip onto anything; hence, minimal friction!
If Teflon is not supposed to stick to anything, then how does it stick to the pan itself?
The production process is surprisingly straightforward. Manufacturers first propel jet streams of abrasive sand against the pan to roughen its surface and engrave as many nooks and crannies as possible. This allows a primer layer of Teflon to lock into these little holes. Since Teflon can easily polymerize, or chemically combine, with itself, they coat the pans in additional layers of Teflon that stick to the primer layer. However, the Teflon coating can be damaged. Excessive heat can break down the carbon bonds, although normal cooking typically doesn’t reach temperatures high enough (about 570 F) to release toxic chemicals in the air. More commonly, metal utensils physically scrape off the Teflon in little flakes. To make your non-stick pans last longer, I would suggest wooden or plastic utensils.
You’re probably wondering how toxic it is for humans to unwittingly ingest tiny flakes of Teflon. The USDA claims the tiny flakes will simply pass through your system, although they suggest not using badly scratched pans. Unlike stainless steel or cast iron pans, non-sticks are meant to be replaced every now and then, especially when there are visible scratches and other signs of damage. Until then, however, take good care of and enjoy the convenience of your non-stick pans! Who would have guessed that classified technology meant for the atomic bomb would revolutionize how we fry our eggs?
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