Insulated Parametric Flask

Generate 250-1000ml flasks with an insulating chamber of air to reduce heat transfer. Set your desired volume and flask radius, and the height will adjust to meet that volume. Clearly, not all volume + radius combinations result in valid models.

More of a design challenge than a practical object, for obvious reasons. If you choose to use as a container for drinks, I recommend only using for COLD liquids, as anything hot may (A) melt the plastic, (B) cause expansion of the insulating space leading to rupture, and (C) release more toxic stuff. I also recommend sealing the inside with food-grade epoxy (it exists!) to reduce transfer of chemicals into your drink.

Print the gasket in flexible filament. It goes inside the cap to prevent leaking.

Use at your own risk; I'm no toxicologist or chemist. Word has it plastic is not health food.