The problem of acid-base stability, if the acid and alkali resistance of defoaming is not good, causes the decomposition of silicone oil, resulting in the failure of defoamer. Some chemical components dissolve silicone oil into the system, so that defoamer no longer has the function of defoaming, but as a surfactant system, the foam of the system will be more than that without adding defoamer.            Correct use of defoamers can achieve twice the result with half the effort. There are many kinds of defoamers on the market, including defoamers for fermentation, defoamers for sewage treatment, organic silicon defoamers, defoamers for textile printing and dyeing, polyether defoamers, etc. Therefore, it is necessary to select the appropriate defoamer according to the industry and application system. Only in this way can the effect be more obvious.