# Wrapping plastic in aluminium foil to protect it from heat

Does it make any sense to wrap the plastic handle of a pan in aluminium foil to protect it from overheating when placing it to the hot oven?

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The foil has two effects: it insulates and reflects.

Thermal insulation does not offer immunity from heat. It reduces the flow of heat. In other words, it delays. In this case, the actual insulation isn't caused by the aluminum foil (which conducts quite well) but by the air layers that it traps.

Reflecting radiation would help if it wasn't happening in an oven. Radiation which is reflected away doesn't turn into heat, but inside the closed environment of an oven the radiation just gets converted to heat somewhere else. It will take a while to get to the handle, so it's another delay.

So, in summary, the foil just buys you a bit of time. From personal experience, I'd estimate it at minutes, certainly less than an hour.

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The insulation effect of Al foil is minimal: Al is a very good conductor of heat (as well as electricity). – hdhondt May 19 '14 at 10:41
@hdhondt That what he also writes, right? – Bernhard May 19 '14 at 13:50
I think gold conducts even better, and yet spacecraft use gold foil – MSalters May 19 '14 at 13:55
And iron and steel are actually a pretty lousy conductors of heat (compared with Al or Au), yet the roast inside the big pot gets quite warm and toasty... Your plastic handle is not going to like it at all, and will make a giant mess inside the oven. – Jon Custer May 19 '14 at 22:14

MSalters answer is all correct, but even in an oven the reflective nature of foil may help (as it would under a grill, but the effect is smaller in an oven). To explain, let's assume the plastic is perfectly black: Wherever the heat is coming from must be hotter than the air in the oven and the other items in the oven. This is particularly obvious if the oven heats with a visibly glowing element, but will be true even if the element is behind a metal panel. A black plastic handle could easily reach a higher temperature than the air temperature (the nominal temperature) in this case. The foil will reflect this radiated heat quite efficiently, significantly slowing the rate of temperature rise.

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Everything will want to go to equiliberium for temperature in the oven.

Aluminium foil is not a good insulator.

Suggest three courses of action:

1. Remove plastic handle

2. find a different pan with a metal handle and use an insulator (i.e. oven mitten) when removing pan from oven

3. find a material with a good insulating value to protect the plastic handle

COA 3 will be the most difficult due to you solution will most likely be large/clumsy and will cost \$

Use the KISS (Keep It Simple Stupid) principle to solve your problem.

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You'd need the oven mitt anyway. Reminds me of my first year undergrad housemate - took a plastic container out of the oven (it was ovenproof) and burnt his hand -"plastic doesn't get hot". He was studying engineering. – Chris H May 19 '14 at 19:35
@ChrisH: He underestimated the effect, but he did have a point. A bad conductor with a low heat capacity might not store enough heat in one place to burn your fingers, nor can it transfer the heat from other places quick enough. – MSalters May 20 '14 at 7:37
@MSalters, true enough, it's an effect we use a lot in cooking and other places. But it's not one I'd recommend relying on when taking a dish from a 200°C oven! In fact your point explains why the burns weren't too bad. – Chris H May 20 '14 at 7:46

No. If your saucepan can take the heat of an oven, the handle needs no protection. If it can't take the heat of an oven, there's really nothing you can do to provide any practical protection to the handle.

Not only will there be heat transfer from the surrounding air (and radiant heat from the heating element/burner and all the hot interior surfaces of the oven), but heat will also be conducting into the handle from the body of the pan.

In all likelihood, to achieve what you want by putting the pan in the oven will require it to be there long enough that the handle is going to approach oven temperature no matter what you do. So, you need a pan with a handle that can withstand such temperatures.

There are some materials we commonly describe as plastics, like bakelite, which can take a lot of heat, but still much less than what you'd commonly use in an oven.

Bottom line: if it doesn't say oven safe on the label, it doesn't belong there, no matter what you try to do with it or to it.

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