ISO 877-2:2009

Overview

ISO 877-2:2009, titled Plastics – Methods of exposure to solar radiation – Part 2: Direct weathering and exposure behind window glass, is an international standard developed by the International Organization for Standardization (ISO). This standard specifies controlled methods for exposing plastic materials directly to solar radiation or behind window glass. The primary goal is to assess the changes in the physical and chemical properties of plastics after defined exposure durations. This enables manufacturers and researchers to evaluate the durability and weather resistance of plastics under real-world sunlight conditions, including the influence of glass-filtered solar radiation.

Key Topics

• Exposure Methods

  • Method A: Direct exposure of plastics to solar radiation in open conditions (direct weathering).
  • Method B: Exposure of plastics behind window glass, where solar radiation is filtered through glass, simulating indoor or sheltered outdoor environments.

• Test Apparatus and Fixtures

  • Specifications for racks and mounting devices that allow controlled inclination and orientation towards the sun.
  • Construction materials for test fixtures include corrosion-resistant metals, such as aluminum alloys or stainless steel, and optionally untreated wood in dry climates.
  • For method B, the exposure fixture consists of an open-bottom box with a flat glass cover allowing solar radiation to pass while protecting specimens from direct weather conditions.

• Exposure Conditions

  • Exposure angle determined by the site latitude and intended application, ranging typically between 0° and 90° tilt from horizontal.
  • Locations free from shadows during sun elevation above 20° are preferred to ensure consistent solar exposure.
  • Consideration of various environments such as urban, rural, and forested areas to simulate actual conditions of use.

• Measurement and Monitoring

  • Use of radiometers positioned behind the glass cover to measure solar radiation dose accurately.
  • Regular cleaning and maintenance of glass covers and test specimens to maintain consistent exposure conditions.
  • Monitoring of climatic factors and solar radiant exposure for precise documentation.

• Results and Reporting

  • Evaluation of property changes caused by solar radiation using systems consistent with other ISO procedures, such as ISO 4582, for color and variation measurement.
  • Standardized test reports capturing duration, conditions, and observed changes for reproducibility and comparison.

Applications

ISO 877-2:2009 is essential for industries and sectors that rely on the long-term performance and stability of plastics exposed to sunlight, including:

• Automotive and Transportation
  Assessing plastics used in vehicle components exposed to direct sunlight or through glass windows.

• Construction and Building Materials
  Testing plastics used in windows, panels, facades, and other building materials that experience varying degrees of solar exposure.

• Consumer Goods
  Evaluating outdoor and indoor plastic products such as furniture, appliances, and packaging for colorfastness, mechanical integrity, and UV resistance.

• Research and Development
  Providing a standardized framework to develop new UV-stabilized or weather-resistant plastic materials.

• Quality Control
  Ensuring consistent product quality and compliance with durability claims through validated exposure testing.

Related Standards

• ISO 877-1:2009 – Plastics - Methods of exposure to solar radiation - Part 1: General guidance
  Provides foundational principles and guidelines applicable to all parts of ISO 877.

• ISO 4582 – Plastics – Determination of changes in colour and variations in properties after exposure to daylight under glass, natural weathering or laboratory light sources
  Standardizes measurement of property changes following solar exposure tests.

• ASTM G 24 – Standard Practice for Conducting Exposures to Daylight Filtered Through Glass
  Supplementary guidance on exposure behind glass, complementing ISO 877-2 protocols.

Practical Value

By adhering to ISO 877-2:2009, manufacturers and testing laboratories can reliably simulate the natural aging process of plastics exposed to sunlight and glass-filtered solar radiation. This enables better prediction of product lifespan, optimization of polymer formulations for enhanced durability, and informed decisions regarding material selection for specific environments. Regular monitoring and standardized reporting ensure transparency and comparability across different studies and regions, reinforcing quality assurance in the global plastics industry.

Keywords: ISO 877-2, plastics solar exposure, direct weathering, exposure behind glass, weathering test methods, solar radiation testing, plastics durability, UV resistance, plastic material aging, standardized weathering test