Overview
ISO 15988:2003 specifies biaxially oriented transparent poly(ethylene terephthalate) (PET) films, primarily intended for packaging use either alone or as laminated film with other materials. The standard covers classification, appearance, dimensional and physical requirements, test methods, packaging and marking to ensure consistent quality and performance for packaging manufacturers, converters and brand owners.
Key elements include classification into two groups (films treated with corona discharge and films not treated), dimensional tolerances, mechanical and barrier property limits, and requirements applicable where food contact is involved.
Key Topics
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Classification: Films are classified as either treated with corona discharge or not treated.
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Appearance: Films shall be free from visible flaws, slackness, wrinkles, stains or foreign matter that impair serviceability. Splices in rolls must be clearly marked.
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Dimensions and tolerances:
- Width and roll length tolerances are agreed between parties; example width steps are in 40 mm increments.
- Inside core diameter tolerances are specified (examples: 76 mm, 152 mm with +2/0 mm tolerance).
- Thickness tolerance: ±10% of nominal thickness (examples provided for common nominal thicknesses).
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Physical and barrier properties (selected limits from the standard):
- Tensile strength at break: ≥ 150 MPa (longitudinal and transverse)
- Tensile strain at break: ≥ 200 %
- Dimensional change on heating: ≤ 3.0 % (longitudinal and transverse)
- Coefficient of oxygen transmission: ≤ 140 fmol·100 µm/m2·s·Pa (expressed per 100 µm)
- Coefficient of water vapour transmission: ≤ 10 g/100 µm·m2·24 h (expressed per 100 µm)
- Haze: ≤ 8 %
- Wetting tension (for corona-treated films): ≥ 40 mN/m
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Test conditions and methods: Conditioning and testing of tensile properties, haze and wetting tension are performed at (23 ± 2) °C, (50 ± 5) % RH after at least 8 h conditioning (ISO 291). Referenced test standards include ISO 527-3, ISO 4593, ISO 14782, ISO 15105-1/2 and ISO 15106-1/2/3 for barrier measurements, and ISO 8296 for wetting tension.
Applications
- Primary use: high-clarity packaging films for consumer goods and industrial products.
- Use cases: standalone packaging films, laminated structures for enhanced barrier performance, and finished packaging where food-contact regulatory compliance is required.
- Practical benefits: predictable barrier properties, mechanical robustness (high tensile strength and elongation), controlled optical quality (low haze) and a printable surface option via corona treatment.
Related Standards
ISO 15988:2003 references and aligns with several ISO test methods and conditioning standards. Key related standards:
- ISO 291 - Standard atmospheres for conditioning and testing
- ISO 527-3 - Tensile properties for films and sheets
- ISO 4593 - Thickness determination for films
- ISO 14782 - Haze determination
- ISO 15105-1/2 - Gas-transmission rate (oxygen) methods
- ISO 15106-1/2/3 - Water vapour transmission methods
- ISO 8296 - Wetting tension
For converters, pack designers and compliance teams, ISO 15988:2003 provides a practical framework to specify, test and accept biaxially oriented PET films with consistent performance for packaging applications.