Overview
ISO 7765-2:2022 specifies an instrumented puncture test for assessing the impact resistance of plastics film and sheeting using the free‑falling dart method. The standard records force‑deflection or force‑time diagrams at nominally constant striker velocity to characterize puncture behaviour, energy absorption and deformation. It applies to films up to 1 mm thickness and is intended when detailed dynamic response data are needed or when only a small number of specimens are available (so the staircase method in ISO 7765‑1 is not suitable).
Key topics and requirements
- Test principle: A striker penetrates the film normal to its plane while instruments record force and deflection. Results include peak force, deformation at peak force, energy to peak and total penetration energy.
- Apparatus: Requires an energy carrier (typically a falling mass/dart), a striker, a clamping device (support and ring), a force sensor (load cell) and a deflection measurement system. A thickness gauge is also required.
- Measured parameters: Peak force (FM), deformation at peak force (sM), energy to peak force (WM) and total penetration energy (WT). Optional failure force/energy definitions are provided where a clear failure point exists.
- Specimen and conditioning: Applicable to films ≤1 mm. Conditioning and test atmosphere follow standard practices (see ISO 291). Thickness measurement references ISO 4593.
- Test execution: Test specimen clamped and impacted at nominally constant striker velocity; electronic recording yields force‑deformation or force‑time diagrams. Data analysis may use mean curves if dynamic resonance affects raw signals.
- Scope for material behaviour: Enables identification of brittle, tough or very tough impact responses and the brittle-to-tough transition by varying temperature, penetration velocity or humidity.
- Alignment and updates: This 2022 second edition replaces ISO 7765‑2:1994 and aligns force measurement and calculation clauses with ISO 6603‑2; it also updates impact failure definitions, clamping guidance and reporting requirements.
Applications and users
ISO 7765‑2:2022 is used by:
- Film manufacturers for product development and quality control
- Test laboratories and materials characterization labs performing impact resistance and puncture testing
- R&D teams comparing energy‑absorption and biaxial deformability of polymer films
- Packaging, medical, automotive and electronics industries where film puncture performance is critical
- Regulatory and compliance bodies specifying test methods for film durability
Practical uses include material selection, formulation optimization, comparative benchmarking and investigating environmental effects (temperature, humidity, strain rate) on puncture performance.
Related standards
- ISO 7765‑1 - Free‑falling dart method (staircase method) for impact failure energy
- ISO 6603‑2 - Instrumented puncture/impact testing alignment for force measurement and calculations
- ISO 291 - Standard atmospheres for conditioning and testing
- ISO 4593 - Film thickness determination by mechanical scanning
Keywords: ISO 7765-2:2022, instrumented puncture test, plastics film impact resistance, free-falling dart method, force-deflection diagram, puncture energy, film testing.
Open preview (PDF)Plastics film and sheeting — Determination of impact resistance by the free-falling dart method — Part 2: Instrumented puncture test