Overview
ISO 527-3:2018 - Plastics - Determination of tensile properties - Part 3: Test conditions for films and sheets - specifies standardized test conditions for measuring the tensile properties of plastic films and sheets thickness ≤ 1 mm. It implements the general principles of ISO 527-1 and gives detailed requirements for specimen shape, preparation, test speeds, measurement of thickness and reporting. The document is intended for flat film and sheet materials and is not normally suitable for cellular plastics or plastics reinforced by textile fibres.
Key topics and technical requirements
- Scope: Applies to films and sheets less than 1 mm thick; for thicker sheets see ISO 527-2.
- Specimen types & dimensions: Preferred strip specimen (type 2): width 10–25 mm, overall length ≥150 mm, gauge length 50 mm ±0.5 mm, initial grip distance 100 mm ±5 mm. Dumb-bell specimens (types 5, 1B, 4) are permitted for specific materials (details and figures provided in the standard).
- Specimen preparation: Cut or punch edges must be smooth and free from notches; use sharp dies or suitable cutters and examine edges with a low-power magnifier. Discard specimens with imperfections.
- Gauge marks & measurement: Two parallel gauge marks required (marking device edge 0.05–0.10 mm wide). Thickness measurement methods: ISO 4593 (mechanical scanning) or ISO 4591 (gravimetric) for very thin or embossed films.
- Test apparatus & speeds: Tensile-testing machine per ISO 527-1, capable of speeds commonly used for films/sheets (5, 50, 100, 200, 300, 500 mm/min). Extensometers must not be carried by the specimen when testing thin films.
- Anisotropy: If film properties vary with orientation, prepare specimens parallel and perpendicular to the orientation direction.
- Number of specimens, conditioning, procedure, calculations: Refer to ISO 527-1 for general rules; ISO 527-3 provides film-specific adaptations.
- Reporting: Include reference to ISO 527-3:2018, specimen type and test speed, plus the standard information listed in ISO 527-1.
- Precision: Interlaboratory precision data are not yet available.
Applications and users
ISO 527-3:2018 is used by:
- Materials laboratories performing tensile testing of plastic films and flexible sheets
- Quality control and R&D teams in packaging, film extrusion, lamination and polymer film manufacturing
- Test laboratories certifying mechanical performance for procurement specifications
- Product designers and regulatory bodies needing standardized tensile data for comparative evaluation
Keywords: ISO 527-3:2018, plastics tensile testing, films and sheets, tensile properties, specimen preparation, test speeds, gauge length.
Related standards
- ISO 527-1:2012 - General principles for tensile testing of plastics
- ISO 527-2 - Test conditions for moulding and extrusion plastics (sheets >1 mm)
- ISO 4593 - Thickness measurement by mechanical scanning
- ISO 4591 - Gravimetric thickness determination