Overview
ISO 9136-2:1999 specifies a laboratory test method for determination of the bulk density of bonded and coated abrasive microgrits. The standard describes required equipment, sample preparation, test conditions and calculation of bulk density expressed in g/cm³. It is intended to provide reproducible results for quality control, product specification and material comparison.
Key Topics
- Scope: Test method for microgrits (Part 2 of ISO 9136). The standard complements Part 1 for macrogrits.
- Equipment: A metering device (vibration-fed funnel and horizontal vibration channel), a polished measuring cylinder and an overspill tray with shield. Example funnel and channel dimensions are provided in the standard to ensure repeatable metering.
- Measuring cylinder: Specified polished inner volume V = (200 ± 0.5) cm³, achieved with an inner diameter of 64 mm and an inner height of 62.2 mm. Calibration methods are given:
- Method A: fill with water under a flat glass plate and determine mass to compute volume using water density.
- Method B: calculate volume from internal dimensions (0.01 mm margin of error).
- Sample preparation: Dry microgrit for 1 hour at 110 °C, cool to room temperature before testing.
- Test conditions: Preferably perform tests at (23 ± 2) °C and relative humidity (50 ± 6) %. Metering speed is adjusted so the measuring cylinder fills in 30–90 s with a steady stream.
- Procedure highlights:
- Place dried microgrit in the funnel; regulate vibration to produce an even stream into the vibration channel.
- Allow the material to heap 2–3 cm above the rim of the measuring cylinder, then level off with a straight blade at ≈45°.
- Avoid vibration during weighing to prevent compaction.
- Calculation: Bulk density (ρB) in g/cm³ is computed as ρB = m1 / V, where m1 is the net mass of microgrit in the measuring cylinder and V is the cylinder volume.
- Repeatability & sampling: Determine bulk density from three samples; the result is the arithmetic mean. Duplicate determinations by the same operator/apparatus shall not differ by more than ±0.02 g/cm³.
Applications
- Quality control of bonded and coated abrasive products to ensure consistent packing and performance.
- Product specification and acceptance testing for manufacturers and suppliers.
- Materials comparison and process optimization in R&D and production.
- Inter-laboratory consistency when the prescribed equipment and procedures are followed.
Related Standards
- ISO 9136-1:1989 - Abrasive grains - Determination of bulk density - Part 1: Macrogrits
- ISO 6344-1:1998 - Coated abrasives - Grain size analysis - Part 1
- ISO 6344-2:1998 - Coated abrasives - Grain size distribution of macrogrits P12 to P220
- ISO 6344-3:1998 - Coated abrasives - Grain size distribution of microgrits P240 to P2500
- ISO 8486-1:1996 and ISO 8486-2:1996 - Bonded abrasives - Grain size distribution designation and determination
This summary highlights the practical elements of ISO 9136-2:1999 for engineers and quality professionals working with abrasive microgrits. For test execution and compliance, refer to the full standard text for exact dimensions, tolerances and procedural figures.