Instrumentation

Die wall pressure is of fundamental importance in the tableting process, and accurate die wall pressure measurements are essential to understand compaction behaviour.

Pressures: up to 350 MPa | Sensors: up to 3 sensors | Temperature: to 80°C

Output: Die wall pressure is captured at three points around the tablet at different heights, alongside upper and lower punch loads through compaction and ejection. Residual radial pressure and residual lower punch load are clearly resolved. Peak die wall pressure and peak residual die wall pressure are presented in tabular form.

Tablet failure often occurs during ejection from the die, and die wall friction is a critical parameter to study for reliable production quality. The Ejection Force Measuring Punch is designed for detailed studies of ejection force during tablet manufacture, and is used on the Huxley Bertram Compaction Simulator or the simple Tablet Test Fixture.

Punch type: B

Results: Force measurement near the punch tip eliminates most inertial forces from the load trace, giving a clean high-frequency response. Inertial effects are only visible at the moments the punch starts to move upwards and when it contacts the tablet.

Temperature is an important factor in any tableting process and especially critical for temperature-sensitive compounds. There has historically been a shortage of reliable internal-tablet temperature data because of the difficulty of measuring at production-press timescales. The Huxley Bertram Temperature Instrumented Punch delivers a fast enough response to capture internal tablet temperatures at typical production press speeds.

Compatible with the temperature-controlled upper punch and die set.

Punch type: B

Results: A clean, high-resolution temperature plot. Comparative tests show that high-speed low-load compactions generate higher temperatures than slow high-load compactions. The thermocouple also detects heat from air compression at the start of the compaction event.

Micro-tablet development presents a different set of challenges for the formulation scientist. With appropriate scale measuring devices and tablet handling accessories, individual micro-tablets can be formed and analysed using the same workflow as full-size tablets.

Punch type: F | Force capacity: 2 kN (standard) | Calibration range: 0–2 kN typical | Linearity: ±0.5% FS

Multi-layer tablet development requires measurement of the bond strength between layers. Tablets made on the simulator can be conveniently tested using the Shear Tester fixture. Rigid construction and high-speed sensitive load measurement give reliable results, and a micrometer measuring fixture enables accurate, repeatable setting of the joint line.

A full load trace shows both peak force and the manner of failure.

Punch type: Shear Tester