What are the functions of different parts of the thermos bottle?
1. Stopper made of plastic or cork - The tight stopper prevents air from entering or leaving the flask, so convection isn't possible either.
2. Silvered inner and outer glass wall - The glass is usually lined with a reflective metal layer. Unbreakable flasks do away with the glass. Instead, they have two layers of stainless steel with a vacuum and a reflecting layer in between them.
3. Vacuum between inner and outer wall - The vacuum prevents conduction.
4. Outer casing made of plastic or metal – the container mounted inside its outer, plastic or metal case