ISO 23145-2:2012

Overview

ISO 23145-2:2012 specifies a laboratory test method for determining the untapped density (untapped bulk density) of granulated or ungranulated ceramic powders using a constant‑volume measuring technique. Part of the ISO 23145 series for fine/advanced ceramics, this standard defines apparatus, sampling, procedure, calculation and reporting requirements for reproducible measurement of bulk density when the powder is simply poured into a container without tapping or compaction.

Key topics and technical requirements

• Scope: Untapped density measurement of ceramic powders by constant-volume method.
• Principle: Measure the mass of powder that freely falls into a stationary container; untapped density = mass/volume.
• Apparatus:
  • Stainless‑steel funnel with orifice Ø 2.5 mm and alternative Ø 5.0 mm (non‑magnetic, corrosion‑resistant).
  • Cylindrical container of 100 cm3 volume with diameter:height ≈ 1.
  • Sieve per ISO 565 (aperture 0.71 mm).
  • Balance with precision 0.1 g (0.01 g for very fluffy powders).
  • Straight edge for levelling, stand and vibration‑free base.
• Sampling and pretreatment:
  • Test powders in the as‑received condition unless drying is required.
  • If dried, heat at (110 ± 5) °C for ≥ 1 h and cool in a desiccator; note any pretreatment.
  • Perform three test portions and average results.
• Procedure highlights:
  • Weigh empty container (m0), fill funnel and allow powder to flow into container, level with straight edge, lightly tap container to prevent spillage, weigh filled container (m1).
  • Use alternative funnel or gentle poking if flow is obstructed (record any such events).
• Calculation:
  • p = (m1 − m0) / V, where V = 100 cm3.
  • Round to 0.001 g·cm−3 (or 1 kg·m−3) per ISO 80000‑1.
• Reporting: Conform to ISO/IEC 17025 - include laboratory ID, environmental conditions, sample identification, pretreatment, untapped density result, and any anomalies.

Applications and users

ISO 23145-2 is used for powder characterization, quality control and process monitoring in industries and labs working with fine and advanced ceramics. Typical users:

• Materials scientists and ceramic engineers
• QA/QC and testing laboratories
• Powder manufacturers and suppliers
• R&D groups developing ceramic components or formulations

Practical applications include batch acceptance testing, comparative evaluation of powder lots, input data for powder handling and forming process design (pressing, granulation, feedstock preparation), and documentation of material properties for procurement or certification.

Related standards

• ISO 23145-1 (Tap density)
• ISO 565 (Test sieves)
• ISO 80000-1 (Quantities and units)
• ISO/IEC 17025 (Laboratory competence)
• ASTM B212, ISO 3923‑1, EN 725‑9, JIS R 1628 / R 1639‑2 (related powder density methods)

Keywords: ISO 23145-2, untapped density, bulk density, ceramic powders, fine ceramics, test method, constant-volume measurement, laboratory testing.