Overview
ISO 17555:2021 specifies requirements and test methods for biaxially oriented polypropylene (BOPP) films used mainly for packaging. It applies to films composed of more than 95% polypropylene (PP) by mass and covers single films and films intended for laminates. The standard defines appearance, dimensional and mechanical property limits, conditioning and test procedures, packaging and marking recommendations.
Key topics and technical requirements
- Scope & classification
- Applies to PP films >95% by mass.
- Two types: Type 1 (surface-treated: corona, flame or plasma) and Type 2 (untreated).
- Appearance
- Films shall be free from flaws, wrinkles, stains or marks that impair serviceability. Splices in rolls should be visibly marked.
- Gloss measured per ISO 2813 when relevant for end-use.
- Dimensions & tolerances
- Width: nominal to +4 mm (examples use 40 mm width steps).
- Roll length: nominal to +1% (table of common roll lengths provided).
- Core inside diameter: preferably 76 mm or 152 mm.
- Thickness: average within ±10% of nominal; measured per ISO 4593 at multiple points depending on film width.
- Mechanical & thermal properties
- Tensile strength at break: ≥ 100 MPa (longitudinal and transverse) - test per ISO 527-3.
- Tensile strain at break: ≤ 270% (longitudinal) and ≤ 150% (transverse).
- Dimensional change on heating: limits of ≤10% (longitudinal) and ≤8% (transverse) after specified heating cycles (120 °C/15 min or 130 °C/5 min).
- Barrier, optical and surface properties
- Water vapour transmission: coefficient requirement (see ISO 15106 series) - film must meet the indicated maximum (table specifies ≤2.0, measured at 40 °C, 90% RH).
- Haze: ≤5.0% for Type 1 (treated) and ≤4.0% for Type 2 (only for transparent films) - per ISO 14782.
- Wetting tension: ≥36 mN/m for Type 1; Type 2 films have lower wetting tension (
