Overview
EN ISO 295:2004 - Plastics: Compression moulding of test specimens of thermosetting materials (ISO 295:2004) sets out general principles and a reproducible procedure for preparing test specimens from heat‑ and pressure‑moulded thermosetting powder moulding compounds (PMCs). The standard covers specimen preparation, mould design guidance and the details to be recorded in a moulding report to ensure comparable test results across laboratories and suppliers. It applies to PMCs based on phenolic, aminoplastic, melamine/phenol, epoxy and unsaturated polyester chemistries and excludes specialized methods required for unusual flow properties.
Key topics and technical requirements
- Scope & purpose: Standardises the preparation of test specimens for property testing of thermosetting materials to improve reproducibility and comparability.
- Apparatus and mould design: Guidance for steel compression moulds (single‑ or multi‑cavity), cavity shapes (e.g., ISO 3167 multipurpose specimen), and practical details such as:
- Recommended plate mould: type E (120 mm × 120 mm) with common specimen thickness of 4 mm.
- Surface finish: mould face roughness Ra 0.4–0.8 µm.
- Dimensional controls: edge taper not greater than 3°, clearance between cavity wall and punch typically ≤ 0.1 mm.
- Material conditioning and charge preparation: Instructions on conditioning powders, drying, preheating and pre‑plastification where applicable.
- Moulding conditions and procedure: Principles for temperature control, curing (crosslinking) time, pressure transmission, and ejection methods to avoid specimen damage.
- Quality & documentation: Required content of the moulding report, precision considerations and specimen marking to trace specimen faces and orientation.
Practical applications
- Ensures consistent, reproducible test specimens for mechanical, thermal, electrical and dimensional testing of thermosetting PMCs.
- Used to produce plates or specimen blanks from which tensile, flexural, impact, electrical and other test pieces are machined.
- Supports quality control, material specifications, incoming inspection and comparative R&D of thermosetting compounds.
Who should use this standard?
- Materials and compound manufacturers (PMC producers)
- Test laboratories and certification bodies
- R&D and product development teams working with thermosetting plastics
- Quality engineers specifying test methods and reporting requirements
Related standards
EN ISO 295 references and complements other ISO standards such as:
Keywords: EN ISO 295:2004, compression moulding, thermosetting materials, test specimens, PMCs, mould design, moulding report.
