Powder defoamers are solid-form antifoaming agents produced through specialized processes that load highly efficient active ingredients (such as polysiloxanes and polyethers) onto porous carriers (like silica or calcium carbonate), followed by drying treatment. Their defoaming mechanism activates when the powder contacts foaming systems: the carrier rapidly releases hydrophobic active components that disrupt foam film elasticity by reducing local surface tension, while simultaneously hydrophobic particles directly puncture bubble membranes to induce rupture. This product form offers significant advantages including convenient transportation, stable storage, and resistance to volatilization deterioration, making it particularly suitable for various dry powder systems such as building dry-mix mortars, powder coatings, detergents, and wettable pesticide powders. Application involves direct blending into dry mixtures whereupon contact with water it delivers sustained defoaming action, effectively controlling process-generated foam while ensuring optimal end-product performance and quality.