Vacuum flask rust for many reasons, the main reason for the material, water, environment and other factors. The material in the iron-containing component of excessive, will rust phenomenon, it is recommended to look at the manual to buy vacuum insulation cup did not indicate what material, 430 materials and 201 materials will be relatively easy to rusty. 2, if it is water, rust, rust-like red spots, cleaning water containing minerals (calcium, magnesium, iron), and the role of the results, such as stain becomes obvious in the following order. (1) citric acid (10G) diluted with warm water and pour into a vacuum flask. (2) for 2-3 hours with a soft brush clean, then rinse with water. (3) it is sufficiently dried. 3, if the vacuum flask open the lid more nearby environment dust, dust will stick on the inner wall surface of the insulated cup may cause rust, it is suggested that the lid tightly closed when not vacuum insulated cup. For further understanding of the vacuum insulated cup product knowledge, can Baidu consult Guangzhou vacuum flask manufacturers Baidu space.