Overview
ISO 9136-1:2004 - Abrasive grains - Determination of bulk density - Part 1: Macrogrits specifies a laboratory test method for measuring the bulk density of bonded and coated abrasive macrogrits. This international standard defines the apparatus, sample preparation, measurement procedure, calibration methods and repeatability requirements for reliable, comparable bulk density data.
Key topics and technical requirements
- Scope: Bulk density test method for bonded and coated abrasive macrogrits (macro-sized grains).
- Apparatus: Stand, funnel, quick‑opening release valve, measuring cylinder and overspill tray.
- Funnel dimensions (preferred): total height 240 mm, top diameter 160 mm, cylindrical outlet 20 ± 0.5 mm diameter, outlet height 40 ± 1 mm.
- Measuring cylinder: nominal volume (200 ± 0.5) cm3; internal diameter 64 mm, internal height 62.2 mm.
- Height of fall (funnel outlet to bottom of measuring cylinder): 138 ± 1 mm.
- Sample preparation:
- Grain sizes F100 or P100 and finer - dry at 110 °C for 1 hour, then cool to room temperature before testing.
- Coarser grains - dry at room temperature.
- Measurement procedure:
- Fill a 250 ml beaker with test grains, pour into funnel with outlet closed, position the measuring cylinder centrally, open valve and allow free fall without vibration.
- Remove heaped material flush with the rim using a straight blade at ~45°; avoid vibration to prevent compaction.
- Weigh the filled measuring cylinder to 0.01 g.
- Calculation: Bulk density ρ = m1 / V (mass of grains in the cylinder divided by the cylinder volume).
- Calibration: Two permitted methods - (A) gravimetric fill with water and glass plate; (B) dimensional measurement of the cylinder. The cylinder volume must be checked regularly.
- Repeatability: Duplicate determinations by the same operator and apparatus should not differ by more than ±0.02 g/cm3.
Applications and users
- Quality control laboratories in abrasives manufacturing to verify batch-to-batch consistency.
- R&D teams developing coated or bonded abrasives where grain packing, dosing and application performance depend on bulk density.
- Procurement and specification engineers validating incoming abrasive grain lots against contract requirements.
- Test houses and certification bodies performing material characterization for product data sheets.
Related standards
- ISO 6344-1 - Coated abrasives: grain size analysis and definitions.
- ISO 8486-1 - Bonded abrasives: grain size designation (Macrogrits F4 to F220).
- ISO 9136-2 - Abrasive grains - Determination of bulk density - Part 2: Microgrits.
Keywords: ISO 9136-1, bulk density, abrasive grains, macrogrits, test method, measuring cylinder, funnel dimensions, calibration, repeatability, coated abrasives, bonded abrasives.
