Oates R J, Mitchell A G
Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada.
J Pharm Pharmacol. 1990 Jun;42(6):388-96. doi: 10.1111/j.2042-7158.1990.tb06577.x.
An indirect method of calculating punch displacement on a rotary tablet press from measurements of the change in punch force with the turret position was in good agreement with direct measurements of punch displacement made using a linear variable displacement transducer (LVDT)-slip ring system. The direct measurements were made during the compaction of three direct compression agents using Manesty punches. However, the agreement between calculated and experimentally determined punch displacements was unsatisfactory when IPT punches were used. The IPT punches have a much flatter punch head profile than the Manesty punches. Due to this difference, the analytic equation does not accurately describe the dynamics of the press under normal operating conditions. Terms in the analytic equation, determined originally under static conditions, were re-evaluated under dynamic conditions for both sets of tooling using the LVDT-slip ring system. Excellent agreement for both IPT and Manesty punches was found between punch displacement calculated using the revised analytic equation and direct experimental measurements. Punch displacements determined from punch head profile and machine geometry only, without taking machine deformations into account, were shown to differ widely from the calculated and experimental values.
一种通过测量冲压力随转塔位置的变化来计算旋转式压片机冲头位移的间接方法，与使用线性可变位移传感器（LVDT）-滑环系统直接测量冲头位移的结果高度一致。直接测量是在使用曼esty冲头压制三种直接压片辅料的过程中进行的。然而，当使用IPT冲头时，计算得出的冲头位移与实验测定的冲头位移之间的一致性并不理想。IPT冲头的冲头头部轮廓比曼esty冲头平坦得多。由于这种差异，解析方程无法准确描述正常运行条件下压片机的动力学特性。最初在静态条件下确定的解析方程中的各项，在动态条件下使用LVDT-滑环系统对两组模具进行了重新评估。使用修订后的解析方程计算出的冲头位移与直接实验测量结果之间，对于IPT和曼esty冲头均显示出极佳的一致性。仅根据冲头头部轮廓和机器几何形状确定的冲头位移，而不考虑机器变形，结果显示与计算值和实验值有很大差异。
