Overview
EN ISO 877-2:2025 - Plastics - Methods of exposure to solar radiation - Part 2: Direct weathering and exposure behind window glass (ISO 877-2:2025) defines standardized outdoor exposure procedures for plastics. It specifies two test methods: Method A (direct exposure to solar radiation) and Method B (exposure behind window glass, i.e., glass‑filtered solar radiation). The standard’s purpose is to provide a repeatable way to assess property changes in plastics after specified exposure stages under natural solar radiation.
Key topics and technical requirements
- Scope and principle: Describes the intent to evaluate changes in physical and appearance properties after natural solar exposure; general guidance is referenced to ISO 877-1:2025.
- Test methods: Method A (direct weathering) and Method B (exposure behind window glass) for assessing effects of unfiltered and glass‑filtered solar radiation respectively.
- Apparatus and fixtures:
- Racks capable of the required inclination; specimens must be at least 0.5 m from the ground or obstructions.
- Racks/holders must allow free shrinkage, expansion or warping with minimal stress.
- Area beneath/in the vicinity of racks should have low reflectance and representative ground cover (e.g., gravel in deserts, low‑cut grass in temperate areas).
- Dedicated test fixtures for Methods A and B and apparatus for measuring climatic factors and solar radiant exposure.
- Specimens and mounting: Guidance on specimen preparation, secure mounting, and avoidance of shadows from nearby objects.
- Exposure stages and measurement:
- Definition of exposure stages and procedures for recording solar radiant exposure and climatic observations.
- Procedures for determining and expressing changes in properties and for preparing a comprehensive test report.
- Documentation: Normative references (notably ISO 877-1) and bibliographic references are included.
Practical applications
- Verifying long‑term performance of plastics used outdoors (façade components, glazing seals, automotive exterior parts, polymeric coatings).
- Comparing formulations, fillers, stabilizers and additives for UV/weather resistance.
- Supporting material selection, quality control, product development and conformity evidence for construction, automotive, consumer products and glazing industries.
- Assessing the difference between direct solar exposure and the effects of glass‑filtered solar radiation for interior‑facing or window‑protected materials.
Who should use this standard
- Materials and compound formulators, test laboratories and OEM test engineers
- Product designers, architects and façade/glazing specifiers
- Regulatory and conformity assessment bodies requiring standardized outdoor weathering data
Related standards
- ISO 877-1:2025 - Plastics - Methods of exposure to solar radiation - Part 1: General guidance (normative reference)
- Other parts of the ISO 877 series for additional exposure methods and guidance
Keywords: EN ISO 877-2:2025, plastics weathering, solar radiation exposure, direct weathering, exposure behind window glass, outdoor aging tests, solar radiant exposure.
