Overview
EN ISO 6186:2023 - Plastics: Determination of pourability (ISO 6186:2023) specifies two simple funnel-based test methods for measuring the pourability (flowability) of plastics in powdered and granular form. The standard measures the flow time of a defined mass or volume through a specified funnel under controlled conditions. Method A provides information relevant to material processability; Method B is optimized for process control during manufacture. The standard notes that the methods may not be suitable for all powdered or granular plastics.
Key topics and technical requirements
- Test principle: Measure time for a defined quantity of material to flow through a funnel of specified dimensions (flow time, in seconds).
- Apparatus:
- Metal funnel (stainless steel example) with polished interior and surface roughness Ra 0,8 (per ISO 21920-2).
- Outlet nozzle diameters: 10 mm, 15 mm, 25 mm (alternate diameters may be agreed and require corresponding funnel height adjustment).
- Funnel support, stopwatch (0.1 s accuracy), balance (0.1 g accuracy).
- Outlet closing device; funnel must be earthed to discharge electrostatic charges.
- Conditioning: Test as received unless atmosphere affects results; optional conditioning 24 h at 23 °C ±1 °C and 50 % ±5 % RH per ISO 291.
- Procedure:
- Start with d = 10 mm; increase nozzle diameter if material does not flow.
- Method A: pour 150 g ±1 g into funnel, prevent compaction, remove closing device and time until empty. Three repeats; clean between tests.
- Method B: overfill funnel, level off, then remove closing device and time until empty. Three repeats.
- If electrostatic effects prevent flow, retest after adding an agreed antistatic agent and record this in the report.
- Results & reporting:
- Report mean flow time (nearest whole second) with method and nozzle (e.g., t = 22 s A10).
- Describe flow behavior: flows too fast / uniformly / intermittently / does not flow.
- Test report must reference the standard, sample ID, moisture content, antistatic agent used (if any), individual results and mean, deviations, and date.
Applications and users
- Practical uses include:
- Quality control and acceptance testing of powdered/granular plastics.
- Processability assessment during material selection for injection molding, extrusion feeding, dosing and hopper design.
- Manufacturing process control to monitor batch-to-batch consistency.
- Troubleshooting powder flow issues and evaluating antistatic treatments.
- Typical users: plastics manufacturers, material suppliers, testing laboratories, R&D teams, and production engineers responsible for powder handling and dosing systems.
Related standards
- ISO 291 - Plastics: standard atmospheres for conditioning and testing.
- ISO 21920-2 - Surface texture and Ra definition (referenced for funnel interior roughness).
Keywords: EN ISO 6186:2023, ISO 6186:2023, pourability, plastics, powdered plastics, granular plastics, flow time, funnel test, method A, method B, process control, processability.
