GranuPack: High resolution tapped density analyzer

Principle

GranuPack instrument is an automated and improved tapped density measurement. This instrument allows us to study the packing dynamics of a powder. The ability of the sample to pack is directly related to the micro properties of the grains such as PSD, shape, roughness. Information on the packing ability (Hausner ratio, Carr index, and characteristic tap number n_1/2) helps to classify powders in terms of flowability and processability.

To perform a measurement, the sample is fed in an initialization tube that will release the powder slowly in the measurement cell. The initialization protocol ensures repeatable pouring of the powder to remove user dependency. Once the cell is filled, a light hollow cylinder is placed on top of the powder bed to keep the interface flat. During the test, the GranuPack will tap the powder with either 1mm or 3mm free fall taps. After each tap, the height of the sample will be measured automatically with an inductive sensor. From the height comes the volume and the density, the software will plot in real-time the packing dynamic of the powder. At the end of the measurement, several characteristics will be displayed in the table like the Hausner Ratio, the Carr index, the bulk density, the final density, and the characteristic tap number n_1/2.

Key Benefits

• Measure the bulk density, the tapped density, Carr index and the Hausner ratio automatically
• Quick measurement
• Measurement is simple and intuitive
• Recorded standard operating procedures increase the repeatability of measurements
• Unique initialization protocol to remove user dependency
• Standard cell compliant with ISO8967, ASTM B527, USP 616, ChP 2020, section 4, Chapter 0993, Page 152, and EP 2.9.34.

Differentiators

• The software is guiding you step by step to perform a measurement both for classic and standard-compliant measurement
• The characteristic tap number n_1/2 to measure the packing dynamics
• The test is fully automated. Once the powder is poured inside the cell the user is no longer required
• All the data are stored in the software and can be accessed and compared easily
• The cell can be dismantled and cleaned easily
• The initialization protocol ensures low to no user dependency
• The measurement features a low decibel level
• The system is closed for safety requirements
• Designed and principle are fully patented and unique

Applications

The GranuPack is compatible with a large range of powders and used in many applications:

• Batch to batch qualification due to its high accuracy (0.4% for metals and 0.6% for excipients)
• Stability of powder bed in AM to insure good layer density homogeneity
• Compaction dynamics for tableting processes in pharma
• Hausner ratio and Carr index to ensure optimal bag filling in the food industry
• Packing dynamics to prevent caking during transportation or due to vibration
• Measurement is fast (15 minutes for a classic test)
• Influence of environmental conditions (humidity, temperature) on powder behavior (cf. figure n_1/2 / RH)

Options

Granupack High-Temperature

The influence of temperature on the packing dynamics can now be investigated thanks to the new GranuPack High-Temperature instrument and its laser sensor. Numerous industrial processes involve powder heating which leads to major modification of the powder packing properties.

For example, the setting of solid bridges due to pre-sintering will have drastic consequences on the packing behavior of the powder.

The GranuPack now allows measurement up to 200°C with its hearing cell controlled directly by the software.

Paper: Influence of temperature on the packing dynamics of polymer powders

Link to the news about the Granupack HT