1. Observe the quality of the inner and outer surfaces of the stainless vacuum flask. A good vacuum flask usually has a smooth inner and outer liner without scratches and bumps. At the same time, pay attention to whether the mouth of the cup is smooth and whether there are welds.
2. To test the thermal insulation performance of stainless vacuum flasks, generally speaking, ss vacuum flask is divided into inner and outer bladders. There is a vacuum between the inner and outer bladders, which can fully ensure the thermal insulation performance of the vacuum flasks. Some inferior vacuum flasks are not vacuum treated, so how to identify them simply?
It's very simple, pour hot water into the cup, tighten the lid, let it stand for a few minutes, and then touch the outer surface and bottom of the cup with your hands. If there is a very obvious burning sensation, it means that the thermal insulation of the flask is relatively poor. If there is no obvious feeling, it means that the thermal insulation performance is basically good. Generally speaking, the normal holding time of the stainless vacuum flask is more than 6 hours.
3. When buying stainless vacuum flasks, you must go to regular shopping malls to buy them, at least from the source of supply, and don't endanger your health for petty profits.
4. When buying brand products of stainless vacuum flasks, general brand vacuum flasks will have manuals, and various materials and parameters will be marked on the instructions. You can choose vacuum flasks according to these data.
5. To test the airtightness of the stainless vacuum flask, the heat preservation performance of the flask is not only affected by vacuum treatment, but also mainly affected by the airtightness of the cup, so how to test the airtightness of the flask? Very simple, fill the flask with water, tighten the lid, place it horizontally for a few minutes, and then put it upside down for a few minutes to see if there is water overflowing. If not, it means that the flask is well sealed and can be used with confidence.