| 摘要 |
A process for making cellulose acetate from wood pulp takes wet wood pulp and instead of converting it into dry pulp sheet which is the usual feedstock for acetate, dries and mechanically separates the pulp into a cellulose flock using a pin mill through which a hot drying gas is passed. Deactivation of the cellulose is avoided by control of the drying gas exit temperature to 80 DEG C to 95 DEG C and of the moisture content of the cellulose flock to 4 to 15% by weight. The flock produced may be acetylated directly without any need for reactivation treatments additional to the normal activation with acetic acid. |
