1. To test the thermal insulation, the main function of the thermal insulation lunch box is to preserve the temperature. So when selecting the thermal insulation lunch box, we must pay attention to the degree of thermal insulation. The test method is also very simple. Generally, we just need to put boiled water into the thermal insulation lunch box, and then cover the lunch box. After three minutes of storage, we can touch the outside of the thermal insulation lunch box with our hands, If the temperature of the outside and bottom is relatively high, it proves that the thermal insulation performance of such a thermal insulation lunch box is generally not very good, and the heat dissipation speed is very fast. Basically, it will become cool after being stored for 2-3 hours.

2. Check the sealing. Another point is that when we add boiling water to test the thermal insulation performance, we can also put the insulation box upside down and observe whether there is water seepage. If there is water seepage, it proves that the sealing of the insulation box is not very good. If we bring some food with soup and water, it is easy to cause spillage.

3. Observe that most of the thermal insulation lunch boxes are made of stainless steel, but some are plastic. If they are plastic thermal insulation lunch boxes, we need to smell the smell of the lunch boxes. If the smell is strong and pungent, we do not recommend that you buy them. How to choose an insulated lunch box? The above is the selection method of insulated lunch boxes. When you choose, you must pay attention to the material of insulated lunch boxes. It is recommended that you buy stainless steel insulated lunch boxes. The thermal insulation performance is very good. Generally, the food you bring in in the morning can be kept warm after noon.