ISO 23145-1:2007

Overview

ISO 23145-1:2007 defines a standardized constant-volume method for determining the tap density (bulk density after tapping) of granulated or ungranulated fine ceramic powders (advanced/technical ceramics). The procedure yields a reproducible measure of the mass per unit volume of a powder after it has been allowed to settle and then compacted by a defined tapping routine.

Key topics and requirements

• Scope: Tap density measurement of ceramic powders using a constant-volume measuring method (Part 1 of ISO 23145).
• Apparatus:
  • Stainless-steel cylindrical container of about 100 cm3 with diameter/height ratio ≈ 1.
  • Ring to increase container height (example dimensions given: ring 50 mm, container ~50 mm diameter × 51 mm height).
  • Sieve per ISO 565 with 0.71 mm opening.
  • Balance precision 0.1 g (use 0.01 g for very fluffy powders such as aerosil).
  • Tap/tamping device with stroke (10 ± 1) mm and frequency < 180 blows/min.
• Procedure highlights:
  • Weigh empty container; fill with sieved powder and tamp with 1 000 blows while maintaining a powder overfill 20–30 mm above container.
  • Remove ring, level excess powder with a straightedge, and weigh.
  • Repeat with 100 blows to check repeatability; difference between the two measured masses must be ≤ 0.3 % (if not, repeat 100‑blow step).
  • Perform three test runs and report the average tap density.
• Pre‑treatment: Drying is permitted when required - (110 ± 10) °C for ≥1 h, cooled in a desiccator; do not dry powders containing volatiles. Desired drying endpoint: mass loss < 0.1 %/30 min (if used).
• Calculation: Tap density = (mass of powder after tamping) / (volume of container). Units reported as g/cm3 or kg/m3.
• Test report requirements: Identification, test date, operator, sample description (material, manufacturer, lot), pre‑treatment, results and observations.

Applications and users

ISO 23145-1 is used for consistent powder characterization and quality control in ceramics manufacturing, R&D and materials laboratories. Typical users:

• Materials and process engineers
• Ceramic powder manufacturers and suppliers
• Quality control and testing laboratories
• R&D groups developing formulations, compaction and sintering processes

Related standards

• ISO 23145-2 (bulk density without tapping)
• ISO 3953, EN 725-8, JIS R 1628, ASTM B527 (related methods for bulk/tap density of powders)

Keywords: ISO 23145-1, tap density, bulk density, ceramic powders, fine ceramics, constant‑volume method, tap tester, powder characterization, powder testing.