ISO 7765-2:2025

Overview

ISO 7765-2:2025 - Plastics film and sheeting - Determination of impact resistance by the free-falling dart method - Part 2: Instrumented puncture test specifies an instrumented puncture test for measuring puncture impact properties of plastic films. The method records force–deflection or force–time diagrams at a nominally constant striker velocity and is applicable to films up to 1 mm thickness. It is intended where detailed characterization of impact behaviour is required or when only a small number of specimens are available (i.e., the staircase method of ISO 7765-1 is not suitable).

Key topics and technical requirements

• Test principle: Free-falling striker (dart) impacts a clamped film while instruments record force and deflection at near-constant striker velocity.
• Measured outputs: Force–deflection and force–time diagrams, peak penetration forces, energy-absorption capacities and biaxial deformability.
• Apparatus components:
  • Test device and energy carrier
  • Striker (dart)
  • Clamping device for specimens
  • Instruments for force measurement and deflection measurement
  • Thickness gauge and conditioning equipment
• Specimen handling: Sampling, preparation, conditioning and a specified test atmosphere are defined to ensure comparable results.
• Result reporting and calculations: Procedures for expressing impact-penetration forces, absorbed energy and transition behaviour between brittle and tough failure modes.
• Scope for variable conditions: Allows determination of the brittle–tough transition region by varying temperature, penetration velocity or relative humidity.
• Precision and test report: Sections on reproducibility/precision and the required elements of the test report are included.

Practical applications and users

• Who uses it:
  • Materials and packaging manufacturers for product development and QC
  • Independent test laboratories and certification bodies
  • R&D teams evaluating polymer formulations, additives or multilayer constructions
  • Industries where film puncture performance is critical (packaging, medical films, automotive interior films, agricultural films, protective covers)
• Why use it:
  • To obtain detailed dynamic response data (force–deflection/force–time) beyond a single failure energy value
  • To compare energy absorption and deformability across materials and thicknesses (≤1 mm)
  • To assess environmental effects (temperature, humidity) and impact speed on puncture resistance
  • To test limited numbers of specimens where staircase methods are impractical

Related standards

• ISO 7765-1 - Plastics film and sheeting - Determination of impact resistance by the free-falling dart method - Part 1: (staircase method) - for single-value failure-energy testing.
• Other parts of the ISO 7765 series for complementary impact-resistance testing and reporting.

Keywords: ISO 7765-2:2025, plastics film, impact resistance, free-falling dart, instrumented puncture test, puncture impact properties, force–deflection, energy absorption.