January 04, 2004

Ask Jen Pete

Victor asks, "How do they get Teflon to stick to pans?" Personally I think that he has been smoking some interesting herbs and spices because people on fresh air don't seem to worry about things like that, but in the interest of science I sent my crack investigative team out and they found the following from CECIL ADAMS:

Smart-aleck radio hosts think this one is sooo funny. Obviously they don't remember the first Teflon pans in the 1960s, which required special non-scratchy cooking utensils, lest you scrape the Teflon off. Fact is, the reaction when Teflon was invented pretty much consisted of, "Whoa, Teflon, the nonstick miracle! So tell us, genius, how do we make it stick to the pan?"

Teflon, known to science as polytetrafluoroethylene, is a pain to work with because it's nonsticky in all directions, the pan side (the bottom) as well as the food side (the top). Teflon is a fluorinated polymer, a polymer being a passel of identical building-block molecules linked together to make a long chain--the stuff of most plastics. Fluorine, due to certain electrochemical properties you'll thank me for not explaining now, bonds so earth tightly with the carbon in Teflon that it's virtually impossible for other substances, e.g., scrambled egg crud, to get a chemical-type grip or, for that matter, for Teflon to get a grip on anything else. In addition, the finished Teflon surface is extremely smooth, giving said egg crud little chance to get a mechanical-type grip.

So how do they get Teflon to stick to the pan? First they sandblast the pan to create a lot of microscratches on its surface. Then they spray on a coat of Teflon primer. This primer, like most primers, is thin, enabling it to flow into the the micro-scratches. The primed surface is then baked at high heat, causing the Teflon to solidify and get a reasonably secure mechanical grip. Next you spray on a finish coat and bake that. (The Teflon finish coat will stick to the Teflon primer coat just fine.) Works a lot better than the early Teflon pans, but you can still ruin Teflon cookware by subjecting it to extremely high heat. This causes the bonds between some of the carbon atoms to break, giving other undesirable stuff a chance to bond thereto and making the Teflon look like Jeff Goldblum in the last reel of The Fly.

Scientists continue to search for something better, and recent reports suggest they may have succeeded. Dow Chemical researcher Donald Schmidt has come up with another fluorinated polymer that can be used like paint and cured with moderate (as opposed to high) heat. Even better, you wind up with a coating that's nonsticky on only one side, presumably the outside. The only drawback: Schmidt's coating won't withstand heat. That doesn't matter if you're trying to make, say, graffiti-proof wall tile, but don't look for Schmidtlon-coated frying pans anytime soon.

So there you have it Victor. Hope that this helps to clear up the issue for you. My crack investigative team is still working on the second part of your question so stay tuned.

Posted by Pete at January 4, 2004 06:20 PM


I was telling my wife this story about Teflon just the other day. She looked at me like something with two heads because I actually knew the details. In the future, I'll just send her along to your blog so that others can get the "you're a freak for knowing that" look from her.

Posted by: physics geek at January 5, 2004 01:25 PM