Defoamers for Brown Stock Washers, 1997 Pulping Conference Proceedings
Foam can be a serious problem on brown stock washers due to the presence of high concentations of fatty acid and resin acid soaps formed during the pulping process. Foam is stabilized by marginally soluble materials that concentrate at the air-water interface. Defoamers are water-insoluble materials that also concentate at the air-water interaface and spread to distrupt the foam. Numerous defoamers are available for brown stock washers. Most consistent of hydrophobic particles dispersed in a hydrocarbon carrier containing oil-soluble surfactants. Some of these products are extended with water. Silicone products have recently been introduced for this application.