Study On Application Of Defoamer Agent In Waterborne Wood Paints

Waterborne wood paints have superior environmental advantages, becausethe dispersion medium is water and there is none volatile organic solvents inuse. But there are different uses of surfactants in the system, which makes itprone to bubbles and difficult to defoaming in waterborne wood paints, this isa common problem. The formation of bubbles in paints production processwill result in ineffective dispersion and overflow. The bubbles will also resultin shrinkage, spot and other surface defects on the film during and afterconstruction. Defoamer agent is a good choice for defoaming in waterbornewood paints.This topic is for waterborne wood paints, focused on various problemsencountered in the process of application of defoamer agents in waterbornewood paints, including selection of defoamer agents, assessment ofdefoaming property and compatibility for defoamer agents, as well aspre-treatment of defoamer agents.There are kinds of defoamer agents in the market, however, there isno universal defoamer agents. So we need to select an excellent defoameragent for a particular emulsion. The selection of defoamer agent consists of three stages in this study. The first stage is the initial selection of defoameragent, through a simple experiment to study defoaming property and thecompatibility between defoamer agent and emulsion. Paint choices in thesecond stage, using the selected defoamer agents by the first stage to producepaint and making an investigation for defoaming property and compatibilityduring the producing process. The third stage is a durable review fordefoaming property. We use density method to evaluate the defoamingproperty for storage over time. After these three stages, we get a gooddefoamer agent for the emulsion.Through three stages in the experiment of choice, we get good defoameragents for the emulsion, which has excellent defoaming property andcompatibility at the same time. In addition, we also found some defoameragents that will have a good defoaming effect with little dosage. But thecompatibility of these defoamer agents with emulsion system is poor, and itrequires high shear dispersion for a long time in the dispersion process.Therefore, it’s difficult to use. In order to make them easy to use, weintroduced high pressure homogenization method for preprocessing them toretain its high defoaming property while improving its compatibility withemulsion, so the defoamer agents can be dispersed under low shear quickly.After the experiment, we successfully achieved this goal.