Overview
ISO 8295:1995 specifies a laboratory method to determine the coefficients of starting (static) and sliding (dynamic) friction for plastics film and sheeting. It applies to non‑sticky plastic film up to approximately 0.5 mm thick and covers film-to-film and film-to-other-material tests. The standard is intended primarily for quality control of slip properties and is not a comprehensive machinability test for processing equipment.
Key topics and technical requirements
- Scope: Non‑sticky plastics film/sheeting, up to ~0.5 mm thickness; film vs film or film vs other surfaces.
- Specimen size & conditioning:
- Test specimens about 80 × 200 mm; at least three pairs sampled across width/circumference.
- Condition specimens ≥16 h in standard atmosphere 23/50 per ISO 291 before testing.
- Apparatus:
- Horizontal test table (flat, smooth, non‑ferromagnetic metal).
- Sled with square contact base of 40 cm² (edge ≈ 63 mm), covered with fine elastic material (felt) to ensure uniform pressure.
- Total sled mass 200 g ±2 g (normal force ≈ 1.96 N ±0.02 N).
- Force‑measuring system with error ≤ ±2% and transition time ≤ 0.5 s; force drag adjusted to 2 N/cm ±1 N/cm for static friction measurements.
- Test speed:
- Normal speed 100 mm/min ±10 mm/min. For specialist films an alternative 500 mm/min ±10 mm/min may be used (must be reported).
- Measurement definitions & procedure:
- Static coefficient ps = Fs / P, where Fs is the peak static frictional force after a specified contact time (15 s before movement in the procedure).
- Dynamic coefficient pd = Fd / P, where Fd is the average frictional force over the first 6 cm of sliding (excluding the static peak).
- Test variants: film vs film, film vs metal or other materials (lower specimen replaced).
- Handling cautions: keep surfaces free of dust, fingerprints; account for additive bloom and ageing; eliminate static electricity before testing.
- Reporting: include reference to ISO 8295, sample identification and age (if known), which surface tested, static and dynamic coefficients, description of other contact materials, and any deviations from the standard.
Applications and users
- Quality control and specification testing in plastic film manufacture, converters, packaging material suppliers, and laboratories verifying slip/anti‑block performance.
- Useful for R&D when comparing slip additives, surface treatments or film formulations.
- Not intended as a full assessment of processing machinability - other factors (electrostatic charge, air cushion, abrasion, temperature) also affect machine performance.
Related standards
- ISO 291 - Standard atmospheres for conditioning and testing (used for specimen conditioning)
- ISO 5725 series - Accuracy (trueness and precision) of measurement methods (used for precision/repeatability assessment)
Keywords: ISO 8295, coefficients of friction, plastics film testing, static friction, dynamic friction, film and sheeting, quality control.
