Abstract
This is a fundamental research on the quantitative evaluation of wet kneaded mass prepared by a paddle type kneader together with the analysis of kneading and the following extrusion granulation processes. A compaction tester of wet kneaded mass has been newly developed and the compression properties of mass are characterized by pressure transmission between the upper and lower punches of the tester. Dispersion condition of a binder liquid among the wet kneaded mass prepared under various kneading times is investigated. Extrusion pressure through a single hole on the lower punch is also measured. The pressure transmission is found to have a linear relationship between the dispersion of binder liquid and the extrusion pressure. This result leads to the conclusion that the proposed method provides the generalized measuring means of the wet kneaded mass. An extrusion granulation by a dome-type extruder is conducted using the wet kneaded mass and physical properties of the extruded pellets, such as friability, specific surface area and disintegration time, are investigated. Good linearity can be found between the pressure transmission and the physical properties of the pellets. As the results of these findings, the kneading condition, i. e., the dispersion of binder liquid among the wet kneaded mass can be understood and the physical properties of pellets prepared by the extrusion granulation can be predicted by the pressure transmission measured by our newly developed compression tester.
