Overview
ISO/TS 21488:2020 - Plastics: Test method for exposing polyolefins outdoors combining natural weathering and artificial irradiation specifies a hybrid outdoor exposure method that combines natural solar weathering (daytime) with controlled artificial irradiation (night or cloudy conditions). The technique preserves the realism of outdoor exposures while accelerating degradation by adding laboratory radiation when sunlight is absent. It is intended for polyolefin materials and products (or product portions) to evaluate changes in visual, optical, mechanical and other properties caused by outdoor service.
Key topics and technical requirements
- Principle: Continuous, cyclical exposure where specimens receive natural outdoor solar radiation during daytime and controlled artificial irradiation (e.g., UVA-340 fluorescent or metal halide sources) during night or low-sun conditions to provide accelerated, realistic weathering.
- Scope and applicability: Specifically for polyolefins; suitable for specimens taken from materials, parts, or full products.
- Apparatus & instrumentation:
- Test chamber or movable box enabling alternating exposure to sun and artificial sources.
- Artificial radiation sources compatible with ISO 4892‑3 (UVA‑340) and IEC 60068‑2‑5 (metal halide).
- Radiometer for measuring radiant exposure, black‑standard / black‑panel thermometer (BPT/WPT), specimen holders and mounting fixtures.
- Test conditions: Control and record radiation, relative humidity, and temperatures (black‑panel, white‑panel, specimen and air temperatures). Time settings for sunrise/sunset and cloudy conditions determine automated day/night switching.
- Procedure: Specimen conditioning, mounting, cyclic exposure (natural then artificial), radiant exposure measurement and scheduled property assessments. Results are reported per the standard’s test‑report requirements.
- Annexes: Informative examples for sites and apparatus design (e.g., a Seosan example and apparatus sketches).
Practical applications and users
- Who uses it: Materials scientists, polymer formulators, test laboratories, product designers, quality control teams, and standards & compliance professionals working with polyethylene, polypropylene and other polyolefins.
- Why use it:
- Estimate outdoor lifetime and performance under realistic environmental cycles.
- Accelerate weathering evaluation in regions with frequent cloud cover or low direct solar irradiance.
- Combine benefits of natural weathering (authentic exposure) with lab irradiation (shorter test time, controlled dose).
- Typical use cases: Outdoor component validation, formulation comparison, qualification testing for outdoor-grade polyolefin products (pipes, geomembranes, packaging components, outdoor fixtures).
Related standards
Keywords: ISO/TS 21488:2020, polyolefins, outdoor weathering, artificial irradiation, accelerated weathering, UVA‑340, metal halide, radiant exposure, black‑panel temperature.