Vacuum insulated bottles are indispensable in people’s daily life. Many people like to drink ice water, and the bottle can keep the water temperature, so many people basically use it. So, why it can keep warm or cold, do you know the principle behind it?
The vacuum insulated bottles is developed from the thermos flask. The principle of heat preservation is the same as that of the thermos flask.. For the convenience of carrying, the flask is made into a bottle. Earlier, people used thermos flasks to store hot water.
There are 3 ways of heat transfer: heat conduction, heat convection and heat radiation. The liner of the bottle is a double-layer glass structure, and the middle is vacuumed to reduce heat conduction; the glass liner is blocked with a cork that is not easy to transfer heat, and hot water can be poured in to reduce heat convection; the liner is coated with Silver, which can reflect the heat radiation inside the bottle back. Don’t underestimate each small thermos bottle, it perfectly uses the three heat transfer methods to achieve the best heat preservation effect.
The earliest thermos bottle liner was the inner liner of a small thermos bottle, but for the convenience of drinking, the inner liner mouth became open. With the development of society, this kind of fragile glass liner thermos cup has been rarely seen, and more thermos cups are made of stainless steel, but the principle of heat preservation is the same.
The stainless steel thermos cup has a double-layer structure, and the inner tank and the two layers of stainless steel on the cup body are welded and combined to form a vacuum, which does not transfer heat; the cock of the thermos cup has good sealing performance, and the heat lost through convection is very small. Copper or silver is plated between the inner tank and the two layers of stainless steel on the cup body, which can effectively reduce the heat lost by radiation. The stainless steel bottle is easy to carry, durable and easy to clean, and has gradually become a new favorite in the market.
Generally speaking, the worst part of a thermos bottle is the bottleneck, so a thermos cup with a large capacity and a small mouth will have a better heat preservation effect. When traveling by car or doing outdoor sports, a large-capacity thermos cup becomes a must-have equipment.
The thermos keeps the temperature not the warmth, so not only does it keep hot water at a certain temperature, but it can also keep things like sorbet at a certain temperature. The structure of the thermos cup makes it difficult for the heat inside to dissipate, and it is not easy for the heat outside to enter the inside, so the thermos cup can keep “warm” and “cold”.