EN ISO 23145-2:2016 specifies a laboratory test method for determining the untapped (un-tapped) bulk density of ceramic powders (granulated or ungranulated) using a constant‑volume measuring method. It forms Part 2 of ISO 23145 (Part 1 covers tap density) and is intended for fine/advanced/technical ceramics where accurate powder bulk density data are needed for materials characterization and quality control.
Key topics & technical requirements
- Scope: Untapped density of ceramic powders measured by allowing powder to fall freely into a fixed-volume container without vibration.
- Principle: Measure mass of a known constant volume of powder after free-fall filling; density = mass / volume.
- Apparatus essentials:
- Funnels with orifice diameters 2.5 mm and 5.0 mm (stainless steel, non‑magnetic).
- Cylindrical container of 100 cm3 volume and diameter:height ≈ 1.
- Sieve per ISO 565 with 0.71 mm aperture.
- Balance precision 0.1 g (or 0.01 g for very fluffy powders).
- Straight edge for levelling and a vibration‑free stand.
- Sampling & pretreatment: Test as‑received unless drying is required. If dried, heating at (110 ± 5) °C for ≥1 h is recommended and drying actions must be recorded.
- Procedure highlights:
- Pass powder through sieve, fill funnel, allow free flow into container, level with straight edge without compression or vibration, tap lightly to avoid spillage, weigh container + powder.
- Perform three test portions and average results.
- Calculation & reporting:
- Untapped density p = (m1 − m0) / V (masses in g, V in cm3). Round to 0.001 g/cm3 (or 1 kg/m3) per ISO 80000‑1.
- Test report must follow ISO/IEC 17025 requirements and include sample ID, environmental conditions, any pretreatment, results and any anomalies (e.g., orifice blockage, powder poking).
Applications - who uses this standard
- Ceramic materials laboratories, R&D and quality control teams in advanced ceramics manufacturing.
- Powder suppliers and formulators for specification, acceptance testing and batch control.
- Process engineers and product developers using bulk density for powder handling, compaction, mixing, spray drying and sintering process design.
- Third‑party testing laboratories seeking accredited, repeatable methods.
Related standards & references
Keywords: EN ISO 23145-2:2016, untapped density, bulk density of ceramic powders, fine ceramics, powder characterization, constant-volume method.
