Overview
EN ISO 527-3:2018 - Plastics - Determination of tensile properties - Part 3: Test conditions for films and sheets - specifies test conditions for determining the tensile properties of plastic films and sheets less than 1 mm thick, based on the general principles in ISO 527-1. It updates and supersedes earlier editions and is adopted by CEN members. The standard is not normally suitable for cellular materials or plastics reinforced by textile fibres; sheets >1 mm should be tested to ISO 527-2.
Key topics and technical requirements
- Scope & applicability: Applies to films and sheets ≤1 mm thickness; refers users to ISO 527-2 for thicker sheets and to ISO 527-1 for general principles.
- Apparatus & test speeds: Tensile-testing machines must maintain specified test speeds. Typical test speeds for films and sheets include 5, 50, 100, 200, 300 and 500 mm/min (as aligned with ISO 527-1).
- Specimens: Preferred specimen is a strip (specimen type 2) - 10–25 mm wide, ≥150 mm long, with 50 mm gauge length. Dumb-bell specimens (types 5, 1B, 4) are allowed for certain materials or routine QC. Initial grip distances and alternative gauge lengths (e.g., reducing gauge for very high elongation materials) are addressed.
- Thickness measurement: Devices complying with ISO 4593 (mechanical scanning) are used for thickness measurement; very thin films (<0.01 mm) or embossed films use ISO 4591 gravimetric techniques.
- Extensometer & grips: Thin specimens shall not carry the weight of the extensometer; grips and cutting/punching methods must produce smooth, notch-free edges.
- Specimen preparation & quality: Cutting, punching, and inspection (low-power magnifier) are specified to avoid edge defects; punch dies must be kept sharp.
- Test procedure & reporting: Clauses cover conditioning, number of specimens, calculation and expression of results, precision and required test report content (see ISO 527-1 for calculation principles).
Applications and users
- Who uses it: Materials laboratories, quality-control teams, R&D departments, film and sheet manufacturers, converters, and procurement/specification engineers.
- Practical uses:
- Characterize tensile strength, modulus and elongation at break for plastic films and sheets.
- Support incoming/outgoing quality control and material qualification.
- Compare materials for packaging, agricultural films, laminates and flexible components.
- Provide standardized data for specifications, compliance and supplier evaluation.
Related standards
- ISO 527-1 - General principles for tensile testing of plastics
- ISO 527-2 - Test conditions for moulded and extruded plastics (sheets >1 mm)
- ISO 4593 - Thickness by mechanical scanning
- ISO 4591 - Gravimetric thickness for very thin or embossed films
By following EN ISO 527-3:2018, organizations obtain repeatable, comparable tensile-property data for thin plastic films and sheets, enabling reliable material selection and quality assurance.