The stainless steel thermos is developed from the insulated water bottle. The principle of insulation is the same as that of the insulated bottle, but people make the bottle into cups for convenience. There are three ways of heat transfer: radiation, convection and transmission. The silver cup gall in the insulating cup can reflect the radiation of hot water. The vacuum of the bottle gall and the bottle body can block the heat transfer, but the bottle which is not easy to transfer the heat can prevent the heat convection. The principle of magnetized water is also applied to the thermos flask, in which magnets are added to the bottom and cap of the bottle to make the water magnetized.
There are many kinds of stainless steel thermos sold on the market, and the price difference is very large. For some consumers, they do not understand the principle and often spend a lot of money to buy unsatisfactory products. How can we buy a high quality vacuum stainless steel thermos?
First of all, it depends on the appearance of the thermos bottle. See if the polishing of the inner and outer surfaces is uniform, whether there are bruises and scratches.
Second, whether the mouth welding is smooth and consistent is related to the comfort of drinking water together.
Third, the quality of plastic parts is poor. Not only will it affect the service life, but also the sanitation of drinking water.
Fourth, see if the internal seal is tight. Whether the screw plug and cup body fit properly. Whether it is free to spin in and out, whether it leaks water. Fill a bottle of water and put it upside down for four or five minutes or shake it forcefully for a few minutes to verify whether it is leaking. Looking at the heat preservation performance, this is the main technical index of the stainless steel thermos. Generally, it is impossible to inspect according to the standard when choosing and purchasing, but it can be inspected by hand feeling after filling hot water. The lower part of the stainless steel thermos bottle with poor thermal insulation effect will be heated after two minutes of filling hot water, while the lower part of the thermos bottle is always cool.