Insulator or conductor depending on the circumstances. Aluminum foil conducts heat, but it cuts off air flow and reduces evaporation of fluids. Aluminum foil reflects and thus minimizes radiation transmission. With foods it is more useful as an insulator. It also acts as an insulator on windows. But, aluminum is definitely a good heat conductor.
Insulator
No
No. Aluminum is a very good conductor of heat.
plastic
yes
Aluminum is a conductor of thermal energy and electrical energy.
It actually isn't a good insulator. Tin foil and aluminum are good conductors, not insulators.
insulators
Aluminum will conduct both electric current and heat, so it would be a bad insulator of either.
If I had to choose the best insulator out of steel wool, aluminum foil, cotton and bubble wrap, I would choose the aluminum foil.
yes it is because it traps the coolness inside.