Because the surface of the bubble film adsorbs the surfactant, the surface tension is reduced. Therefore, under local pressure, the bubble film becomes thinner at the same time, and the surface tension will increase due to the thinning of the surfactant. It is precisely because of the difference in surface tension between the new surface and the original surface that when the bubble film is thinned by external impacts, an elastic restoring force is generated, so that the bubble film can not be broken and plays a role in stabilizing the bubble. If we manage to disrupt this elasticity, we can disrupt the stability of the bubble. Some experts believe that the role of the defoamer is to destroy the elasticity of the bubble film. When the defoamer is added to the foam system, it will diffuse to the air-liquid interface, making it difficult for surfactants with foam stabilization effect to recover the elasticity of the membrane.