EFFECT OF POLY(VINYL ALCOHOL) ADSORPTION ON BINDER SEGREGATION DURINGDRYING

The effect of poly(vinyl alcohol) adsorption on segregation was quanti tatively studied by a model experiment of one-dimension drying and sim ulated by a mathematical model, It was clear that the adsorption of PV A on alumina particle was a slow process, and the adsorbed binder was not desorbed at higher temperature. PVA segregation can significantly be limited by fully adsorbing the binder before drying. The simulation and experiments agreed very well. The effects of drying temperature, initial concentration of the binder, and thickness of specimen on the surface segregation are discussed quantitatively. Mathematical simulat ion has a great potential for predicting the segregation of soluble co mponents during drying, especially for such cases as thin films and sm all granules where it is difficult to determine the distribution of th e component directly.