Overview
ISO 294-3:2020 - "Plastics - Injection moulding of test specimens of thermoplastic materials - Part 3: Small plates" specifies dedicated two-cavity ISO moulds (type D11 and D12) for producing 60 mm × 60 mm test plates. The standard defines mould geometry, gating, runner and sensor locations, and procedural points used to produce consistent thermoplastic test specimens for mechanical and physical testing. It also describes optional inserts to generate weld lines for targeted property studies (Annex A).
Key topics and technical requirements
- Specimen dimensions: Plates 60 × 60 mm; preferred thickness 1.0 ± 0.1 mm (D11) or 2.0 ± 0.1 mm (D12).
- Mould type: Two-cavity, one-end gated ISO moulds with interchangeable cavity plates and gate inserts.
- Sprue and runner:
- Sprue diameter (nozzle side) ≥ 4 mm (per ISO 294-1).
- Runner length 25–30 mm; runner depth = plate thickness h; runner width at gate ≥ (plate width + 6 mm).
- Gate length 4.0 ± 0.1 mm; gate height (75 ± 5)% of cavity height.
- Moulding controls & instrumentation:
- Pressure sensor position within the cavity is mandatory for moulding shrinkage measurement per ISO 294-4; sensor must be flush with the cavity surface.
- Ejector pins (if used) must be outside the 50 mm central test area.
- Heating/cooling systems and polishing/interchangeable features per ISO 294-1.
- Injection-moulding machine: Recommended minimum locking force example - ≈880 kN (for maximum melt pressure 80 MPa).
- Procedure notes:
- Material conditioning and general injection procedures per ISO 294-1:2017.
- Recommended injection velocity: comparable to that used for type A ISO moulds.
- Reporting: Test-specimen preparation report must reference ISO 294-3:2020 and include required process and moulding details (see ISO 294-1 Clause 6).
Applications and who uses it
- Used by materials laboratories, plastics test labs, R&D groups, quality control teams, mould designers and injection moulding manufacturers to:
- Produce standardized small plates for tensile, impact, shrinkage and optical tests.
- Study weld line effects using inserts (Annex A) and generate reproducible specimens for tensile or tensile-impact testing.
- Validate mould designs, control process variables, and compare material performance with consistent specimen geometry.
- Useful for material suppliers, certification bodies and engineers requiring traceable, comparable thermoplastic test data.
Related standards
Keywords: ISO 294-3:2020, injection moulding, thermoplastic test specimens, small plates, D11 D12 ISO mould, moulding shrinkage, weld lines, pressure sensor.
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