How is a thermos flask made? Why do they use silver colour to paint it?

Answer 1

Themosflask is designed to prevent transfer of heat from or to the material kept in the flask. Transfer of heat takes place through three modes, namely 1. conduction, 2. convection, and 3. radiation.
Transfer of heat simply by contact without any movement of the particles is conduction.Convection is through movement of particles and for radiation no medium is required.
The container is made up of or covered with a bad conductor,threby conduction is minimised.The flask ie. the inner container is made up of two layers of glass and vacuum is created inbetween, so that there is no medium for transfering heat through convection.

The inner glass layers are coated with mercur;y so that the heat rays passing through the flask are continuously reflected and entangled in between the two coated layers, therby preventng transfer of heat through radiation.
No scope for loosing or gaining heat. Fine? Let us have a hot coffee or a cool drink from the thermos.

Answer 2

The thermos flask is made by plastic and metallic glass and they use silver colour to paint because the heat or cold objects kept in the flask will remain at around same tempature because the silver colour cannot obsurpe the heat and cold temparatures and it will reflects the heat or cold into inside it so the drink kept in thermos flask keeps at constant temparature for long time where as in another flasks it will not constant

Answer 3

thermos flask is made up of glass with twin walled chamber.
the glass is blown when in elastic condition inside a mould to get the shape and simultaneously pressurised from the opposie end o form as twin walled chamber. there is a sharp buylb which is delicae at the bottom of the flask which was the starting point of blowing.
very small volume of hot air is entrapped in between the 2 walls of the flask.
it is almost equivalent to a condition of vacuum in between the 2 glass walls in the thermos flask.

they paint the outer wall portion of the twin wall which is holding the air with silver paint in order to reflect the heat back to the fluid which is poured into the flask.the layer touching hot coffee or milk side will be plain glass and the layer in contact with air and the outer layers inner side will be painted with silver paint which will make the glass hold the heat for a longer time in the fluid.

Answer 4

Thermos flasks work by having 2 containers. The main container (that holds the liquid) is sealed inside a 2nd container with a void between them, meaning, no air, nothing... this void stops heat or cold from escaping from the thermos. The silver furthers this protection.

Joke:

A blonde walked into the lunchroom and proudly showed off her new thermos to her co-workers. "It keeps hot things hot, and cold things cold!" she exclaimed... When asked what she had in the thermos, she brightly replied "2 cups of coffee and a popsicle!"

Answer 5

thermos flask is made of two layers of glasses with a vaccum between them.. this vaccumn prevents conduction of heat. usually its inner walls are coated with silver colour because that colour have the tendancy to reflect rays..so that the heat or cold ill remain unchanged for some hours..it'll be having a tip at its bottom.if that tip is broken the vaccum between d 2 walls will be filled by air ,as a result conduction will take place resulting in loss of original temperature
so handle it carefully while u experiment with it :-)

Answer 6

thermos flask keeps the water hot or cold, so the shiny surface like silver can insulate the heat.

Answer 7

The stopper is usually made of plastic which is a poor conductor of heat and prevents loss of heat 4m top due 2 conduction. the flask is closed at top n warm air cannot escape 4m the top so no loss of heat by convection. the outer surface of inner wall and inner surface of outer wall are silvered n shiny. thus, heat 4m inside cannot escape n heat 4m outside cannot enter by radiation as silvered inner n outer surfaces reflect back this heat.