What factors determine the insulation time of insulated water cups and insulated kettles

The thermal insulation principle of the thermos cup is to isolate the temperature from being transmitted outwards under the vacuum state between the double-layer sandwich walls to maintain heat. I believe many friends know the principle of cold air falling and hot air rising. Although the hot water in the thermos cup cannot conduct heat outward through the wall of the water cup, when the hot air rises, the heat will be conducted outward through the cup cover. Therefore, the temperature of the hot water in the thermos cup Most of it is passed from the mouth of the cup to the lid.

Knowing this, for a thermos cup with the same capacity, the larger the mouth diameter, the faster the heat conduction will be. For a thermos cup of the same style, the water cup with a good lid insulation effect will have a relatively longer heat preservation time. From the appearance, For similar cup lids, the plug-type cup lid has a better heat preservation effect than the ordinary flat-head screw-top cup lid.

In addition to the appearance comparison mentioned above, what is more important is the vacuuming effect and the welding quality of the water cup. Regardless of the type of stainless steel thermos cup, a welding process will be used. The welding quality will directly affect whether the water cup is insulated, how long it will be kept warm, etc. Usually the welding processes currently used by water cup factories are argon arc welding and laser welding. The welding is incomplete or the welding is seriously missed. Those with relatively thin solder joints, incomplete or weak soldering will usually be picked out after the vacuuming process, but due to the same time and normal temperature when vacuuming together Some water cups will also have different vacuum integrity due to the size of the getter. This is why the same batch of insulated cups will have different insulation times.
Another reason is that the weak welding is not obvious and has not been picked out through inspection before it appears. When consumers use it, the position of the virtual welding is broken or expanded due to impacts and falls, etc. This is why some consumers just The thermal insulation effect is still very good when in use, but after a period of time the thermal insulation effect decreases significantly.

In addition to the above various reasons that have an impact on the insulation time of the thermos cup, frequent alternation of hot and cold water and long-term use of acidic drinks also have an impact on the insulation time.