1. Choose the right material: the stainless steel vacuum flask must be 304 stainless steel or 316 stainless steel, and the inner tank should be 304 steel, so as to ensure that the heavy metal dissolved in the vacuum flask for water does not exceed the standard, including lead. The amount of heavy metal dissolved in the stainless steel cup of 201 or 202 is more than 100 times that of 304 steel. Insulation cup made of 304 steel cup, there must be material 304 on the outer packaging, which is easy to identify.
2. Choose products that use tailless vacuum: the vacuum of stainless steel vacuum flasks currently on the market is divided into tailed vacuum and tailless vacuum. The former is a traditional process, and the latter is a process at home and abroad. Tailless vacuum products have high vacuum, long holding time, large effective capacity and long service life.
3. Pay attention to the design details of the inner container and cup lid: the surface of the inner container and outer container of a good vacuum flask is uniformly polished, the interface is well-made, the edge of the vacuum cup mouth is smooth and flat, and the screwing of the lid and the cup mouth should be flexible. Clearance, the cup lid plastic has no peculiar smell, and the appearance of the product can be customized according to the crowd.
