RESEARCHES ON ACTIVE CLAY APPLIED TO PAPER INDUSTRY

Bentonite can be used as a sizing material and when it is used in rosin sizing, it can improve the weakness of rosin sizing and increase size. In this experiment, the standard process of hand-made paper screening is first determined, explained, and then the precision of size test is obtained. It is shown that size degree should be represented by statistical method. According to this method, we obtained the following results and made considerations on them.(1) Sizing can be made by bentonite only. In this case both lodding and sizing effects are obtained.(2) When bentonite is added in rosin sizing, it increases size degree and makes rosin size more stable and firm.(3) This characteristic is due to its property of lyophile colloid and the larger the swelling degree is, the better.(4) When acidic clay (SANSEI-HAKUDO) is used, it can prevent, to some extent, the decrease of size in steam drying, but sizing is apt to be mottled.