Aug 18 2007
Instron, a leading provider of testing equipment designed to evaluate the mechanical properties of materials and components, announces its collaboration with Huxley Bertram Engineering of Cambridge, to redevelop the ESH Powder Compaction Simulator, a key piece of equipment in the pharmaceutical development laboratory.
Designed to characterize new and existing powder formulations to allow reliable transfer of tablet designs from laboratory to production press, the simulator is built to pharmaceutical standards and contains two seal-less hydraulic actuators supplied by Instron. Advanced hydraulic design and control loop “Gain Scheduling” give significant improvements in the speed and precision of powder compaction testing.
The simulator’s design includes a pair of vertically-opposed highly dynamic hydraulic actuators mounted in a very stiff load frame. Operating speeds over 1 m/s are achieved, over very short travels with rapidly changing loads, requiring very precise control. Special transducers and amplifiers are used to give the precision and synchronization required for control and measurement of compression events, lasting only a few milliseconds. The new machine design has been reduced in size and is consequently stiffer, resulting in better control and easy access for operation or cleaning.
Instron’s 8800 Controller is used to achieve accuracy at high speed and uses a very high loop gain in combination with high response control valves. It allows optimization of all four control loop terms according to the load applied, resulting in loop gain values twice as high as would be possible without it. Crucially, the Integral control term can be manipulated to reduce errors according to the load experienced. Since the loop gains are updating in real time, it is not necessary to run cyclic tests or repeated tests to achieve reduced errors.
The ESH Powder Compaction Simulator is manufactured and marketed by Huxley Bertram Engineering Limited.