Overview - ISO 8460:1987 (Instant coffee bulk density testing)
ISO 8460:1987 specifies laboratory methods to determine the free‑flow (untamped) and compacted (tamped) bulk densities of instant (soluble) coffee. These standardized tests define apparatus, sample handling, operating steps and reporting requirements so manufacturers, packers and test laboratories can consistently measure how much volume a given mass of instant coffee occupies.
Key topics and technical requirements
- Two methods covered
- Free‑flow bulk density: pour a sample through a specified hopper/funnel into a cylindrical receptacle (approx. 205 ml) and weigh the filled receptacle.
- Compacted bulk density: place a fixed mass (typically 25 g) into a 250 ml graduated cylinder and apply a fixed number of taps (generally 300) using a tapping/tamping volumeter; read resulting volume.
- Apparatus and dimensions
- Hopper/trémie mounted at a constant distance (40.0 ± 1.5 mm) above receptacle top.
- Receptacle: cylindrical stainless steel, capacity known to 1 ml.
- Tapping device per ISO 787‑11: cam, support, foot drop height 3 ± 0.1 mm, rotation frequency 250 ± 15 min⁻¹, counter and low‑friction guide.
- Measurement precision and calculations
- Use a balance accurate to 0.1 g.
- Free‑flow density = mass of coffee (difference between filled and empty receptacle) divided by receptacle volume (g/ml).
- Compacted density = sample mass divided by post‑tapping volume (g/ml); volume read to 2 ml.
- Repeatability: two determinations on same sample must agree within 2% of the mean.
- Environmental and sampling notes
- Tests should not be carried out in high humidity (avoid >60% relative humidity for free‑flow; similar warnings apply for tamped tests).
- Follow ISO 6670 sampling guidance (annex B referenced).
Practical applications and users
- Who uses ISO 8460:
- Instant coffee manufacturers and formulation labs
- Quality control and R&D laboratories
- Packaging engineers and fill‑line operators
- Trade/inspection bodies and regulatory labs
- Why it matters:
- Ensures consistent filling and accurate net weight control for powders
- Helps assess handling effects (settling, breakage) on volume and bulk density
- Informs packing design, container sizing and logistics
Related standards
Keywords: ISO 8460, instant coffee, bulk density, free‑flow density, compacted bulk density, tapping volumeter, coffee soluble testing, packing and QC.
