Force-Time-Curves of a Modern Rotary Tablet Machine I. Evaluation Techniques and Characterization of Deformation Behaviour of Pharmaceutical Substances

Abstract

According to the geometry of punch heads and the interdependent punch movements force-time-curves of a rotary-tablet press are divided into periods by the aid of the signal of an inductive sensor. The decrease of compaction load in the interval of the flat punch top is mainly due to plastic flow of the compressed substances. Brittle or plastic deformation behaviour is easily distinguished and quantified by the combination of a standard press and a highly advanced data acquisition and off-line software evaluation. Additionally it is shown that there is no need to use a complex equipment for displacement measurement to gather reliable data on compaction mechanisms. Even if the machine deformation is considered, calculated displacement data may surpass measured data in precision.