The vacuum insulation layer in the thermos cup can delay the heat dissipation of the water and other liquids inside, so as to achieve the purpose of heat preservation.
The main reason why the thermos cup can keep warm is because the container has three characteristics in structure:
(1) The mouth of the bottle liner is made smaller, and the mouth of the bottle is covered with a cork stopper, which can reduce evaporation, prevent the flow of gas on the liquid surface, and reduce the loss of heat.
(2) The cup is made of double-layer glass. Both glass and cork are poor conductors of heat. The distance between the layers is only 8 mm. The interlayer is vacuumed to effectively prevent heat conduction.
(3) The double-layer glass surface of the bottle liner is evenly plated with a layer of silver. The bright silver-plated surface can return the heat radiation that reaches the surface, thus preventing the heat loss due to heat radiation.