304 food grade, no problem. First of all, it is recommended to drink water from a stainless steel cup, and secondly, it is recommended to drink water from glass or ceramics.
1. For the purpose of health care, we often add other auxiliary materials, such as stones or other substances, to the water to increase the negative ions of water or change other physical properties of water. Take negative ions as an example. Drinking water from a plastic cup can't increase negative ions, stainless steel is the best, glass ceramics are barely. But there is also a problem with stainless steel, which is nickel release, but this is very small.
2. It should be noted that do not drink tea with stainless steel. Usually tea contains a variety of vitamins, in addition to a large amount of theophylline, tea sesame oil, and tannic acid. The tea leaves in the stainless steel thermos cup are soaked in high temperature water for a long time, which will lead to the destruction of various vitamins in the tea leaves, the tannic acid and theophylline will seep out in large quantities at the same time, and the tea sesame oil will also volatilize in large quantities.
Expansion information
1. The stainless steel thermos cup is made of double-layer stainless steel inside and outside. The inner tank and the outer shell are combined by welding technology, and then the air in the interlayer between the inner tank and the outer shell is extracted by vacuum technology to achieve the effect of vacuum insulation. .
2. Stainless steel thermos cups are divided into: ordinary thermos cups (the heat preservation time is generally less than three hours after the boiling water is poured in), vacuum thermos cups (through the vacuuming process, the boiling water can be kept warm for more than 8 hours). Generally speaking, the cup material The thinner it is, the longer the hold time.
3. However, the cup body is easy to be damaged and deformed, which affects the service life; measures such as coating the outer layer of the vacuum cup with metal film and copper plating can also increase the degree of heat preservation; the vacuum cup with large capacity and small diameter has a longer heat preservation time, on the contrary Small-capacity, large-diameter vacuum insulated cups have a short holding time; the service life of the vacuum cup also depends on the cleaning of the inner layer of the cup and the vacuuming time, and the most important thing is the structure of the vacuum furnace.