Overview
EN ISO 61:2023 (ISO 61:2023) specifies a laboratory method for determining the apparent density (mass per unit apparent volume) of loose moulding materials that cannot be poured through a specified funnel. Published by CEN/ISO, this standard applies to loose plastics moulding materials such as slice, granular or powder and updates the earlier edition (supersedes EN ISO 61:1999).
Key topics and technical requirements
- Scope: Apparent density test for materials that do not flow through the funnel covered by ISO 60 (ISO 60 is referenced for pourable materials).
- Apparatus:
- Balance accurate to 0.1 g
- Ruler accurate to 1 mm
- Measuring cylinder: smoothly finished, capacity (1000 ± 20) ml, internal diameter (90 ± 2) mm
- Plunger: hollow cylinder, mass (2300 ± 20) g, diameter slightly less than cylinder internal diameter
- Procedure:
- Place (60 ± 0.2) g of material little by little into the measuring cylinder, level the surface.
- Lower the plunger slowly until fully supported by the material; wait 1 minute and measure material height to nearest 1 mm.
- Perform three determinations on the sample. Test samples shall not be reused.
- Calculation and reporting:
- Apparent density d (g/ml) is calculated by d = m / (A · h), where m = mass (g), A = cross-sectional area (cm²) and h = height (cm).
- Report the arithmetic mean of three determinations and take two significant digits.
- Test report must reference ISO 61:2023 and include material ID, individual results and mean, statistical data if required (standard deviation, coefficient of variation or confidence limits), observations and test date.
Applications and users
- Quality control and incoming inspection of plastic compounds, powders and granules
- R&D and materials characterization in plastics manufacturing and compounding
- Test laboratories and certification bodies performing standardized physical tests
- Process engineers using apparent density to inform feed systems, dosing, and molding process settings
Keywords: EN ISO 61:2023, ISO 61:2023, apparent density, plastics, moulding material, measuring cylinder, plunger, test method, loose moulding materials.
Related standards
- ISO 60 - Determination of apparent density for materials that can be poured from a specified funnel (recommended complementary method).
