ISO 7765-1:1988

Overview

ISO 7765-1:1988 specifies a reproducible test procedure to determine the impact resistance of plastics film and sheeting (thickness < 1 mm) by the free‑falling dart (dart impact) staircase method. The standard defines two test variants:

• Method A: 38 mm diameter hemispherical dart, drop height 0.66 m (suitable for approx. 0.05 kg–2 kg mass range).
• Method B: 50 mm diameter hemispherical dart, drop height 1.50 m (suitable for approx. 0.3 kg–2 kg mass range).

The aim is to establish the projectile mass that causes failure in 50% of the specimens under specified conditions using a controlled mass‑increment “staircase” procedure.

Key topics and requirements

• Scope: Films and sheets less than 1 mm thick; test gives a statistically estimated mass (or energy proxy) producing 50% failures.
• Test technique: Staircase (up/down) method - after each impact the dart mass is increased or decreased by a constant increment (Am) depending on whether the specimen failed.
• Dart and apparatus: Hemispherical darts mounted on rods (specified lengths and diameters), a specimen holder with jaws, electromagnet or other reproducible release device, blocking collar for added masses, protective shielding and damping.
• Mass increments and sample planning: Recommended Am typically 5–15% of the expected 50% rupture mass; choose increments so 3–6 mass levels are used. Prepare sufficient material to provide at least 30 test specimens.
• Conditioning and environment: Specimens conditioned at 23 °C ±2 °C and 50% ±5% relative humidity for at least 40 hours (tighter tolerances for disputes).
• Specimen requirements: Free of visible defects, thickness within ±10% of nominal; avoid slippage in the clamp (techniques to detect and prevent slippage are specified).
• Stopping/analysis rules: The staircase procedure yields a calculated “mass of rupture” for 50% failure; the standard includes rules for test sequencing and basic stopping criteria (e.g., counting failures after a prescribed number of trials).

Applications and users

ISO 7765-1 is widely used for:

• Quality control and production acceptance testing of flexible packaging films and industrial sheeting
• Material specification and supplier comparisons
• R&D and formulation development for polymer films (packaging, medical, agricultural films, liners)
• Independent testing laboratories and certification bodies Typical users: film manufacturers, converters, packaging engineers, QA/QC labs, material scientists.

Related standards

• ISO 7765-2 (Plastics film and sheeting - other dart/penetration methods)
• ISO 291 (conditioning atmospheres)
• ISO 4591 / ISO 4593 (methods for measuring film/sheet thickness)

Keywords: ISO 7765-1, plastics film impact resistance, free‑falling dart, staircase method, dart impact test, film testing, sheeting impact test, packaging film quality.