The thermos cup is generally a water container made of ceramic or stainless steel plus a vacuum layer. The top has a cover and is tightly sealed. The vacuum insulation layer can delay the heat dissipation of the water and other liquids contained in it, so as to achieve the purpose of heat preservation.
The thermos cup is developed from the thermos bottle. The principle of insulation is the same as that of the thermos bottle, but people make the bottle into a cup for convenience.
