First, look at the label identification, whether it is detailed and scientific.
Second, look at the material. 304 and 316 stainless steel are preferred for the inner tank, but other materials can also be selected as long as they are clearly marked and meet the national safety standards. Pay attention to the inside of the cup cover in direct contact with the contents and the material of the straw to see whether it meets the food safety standards. Basically, there are few 201 materials selected now, unless they are shoddy. Most of the household dining utensils in the market will choose 304 as the first choice, because 304 stainless steel is stronger than 201 in strength and corrosion resistance. Of course, the standard of 316 is higher, and the production cost is relatively high. When selecting a vacuum flask, at least 304 stainless steel vacuum flask should be taken as the minimum standard. The outer packaging instructions of many cups and other utensils will even be stamped with steel seal SUS304 or 18 / 8. Both of them can be selected. 18 / 8 is an index ratio, that is, the ratio of chromium to nickel is 18:8, which is the ratio of 304 stainless steel. When chromium and nickel are 18 / 10, it is a higher level of 316 stainless steel. However, there are still few 316 stainless steel materials on the market. After all, the cost is much higher.
Third, look at the appearance. Pay attention to whether the external surface, welding position, printed words and patterns of the cup are normal, and check whether the switch button of the cup cover is normal, and whether the rotation performance and sealing are guaranteed; Check whether all parts are easy to disassemble, wash and reassemble.
Fourth, look at heat preservation and energy efficiency. When the product is placed at the specified ambient temperature of 20 ℃± 5 ℃, the higher the retention temperature of 95 ℃± 1 ℃ hot water after the specified time, the better the thermal insulation efficiency.