ISO 1600:1990

Overview

ISO 1600:1990 - Plastics - Cellulose acetate - Determination of light absorption on moulded specimens produced using different periods of heating provides a standardized test method for assessing the light absorption properties of cellulose acetate plastics. This standard outlines procedures for preparing and moulding specimens under controlled heating conditions, then measuring their ability to absorb visible light. While the method is primarily intended for cellulose acetate with a specific acetic acid yield (54% ± 2.5%), it may also apply to other transparent, non-strongly coloured plastics that can be processed under similar conditions.

By quantifying light absorption at both the blue and red ends of the visible spectrum, this ISO standard enables consistent characterization of changes in transparency, yellowness, and lightness due to different moulding conditions. Such data support quality assurance and ensure material performance in applications where optical clarity is critical.

Key Topics

• Scope of Application: Targeted at cellulose acetate, but suitable for similar transparent plastics not strongly coloured.
• Test Methodology:
  • Preparation of material, including two options for incorporating plasticizers.
  • Die moulding of specimens using controlled heating durations.
  • Determination of initial and post-heating optical density using photoelectric absorptiometry at defined wavelengths.
• Measurement Principles:
  • Absorption measured at approximately 440 nm (blue) and 640 nm (red) characterizes material transparency.
  • Calculating light absorption based on specimen thickness standardizes results (optical density at 25 mm).
• Safety Considerations: Highlights the need for proper safety and health protocols due to potentially hazardous chemicals and equipment.

Applications

ISO 1600:1990 is utilized in various stages from product development to quality control for plastics where optical clarity and color stability are essential. Its practical value includes:

• Material Selection and Comparison: By quantifying optical density, manufacturers and product designers can select the most suitable materials for applications such as transparent packaging, optical components, and display panels.
• Process Optimization: Enables plastics processors to understand how heating time during moulding affects the optical properties of cellulose acetate, optimizing production parameters.
• Quality Assurance: Provides a repeatable method for verifying the consistency of light absorption properties across product batches.
• Research and Development: Useful for comparative studies and innovation in transparent or light-sensitive plastics.

Industries such as automotive, consumer electronics, packaging, and lighting benefit from the insights provided by this testing standard, ensuring compliance with material specifications and customer requirements.

Related Standards

For a complete approach to testing and evaluation of plastics, the following related international standards may also be relevant:

• ISO 565:1990 – Test sieves - Metal wire cloth, perforated metal plate and electroformed sheet - Nominal sizes of openings (referenced for sample preparation).
• ISO 585:1990 – Plastics - Unplasticized cellulose acetate - Determination of moisture content.
• ISO 527 – Plastics-Determination of tensile properties (for mechanical characterization).
• ISO 2813 – Paints and varnishes-Determination of gloss value at 20°, 60°, and 85° (complementary for appearance properties).
• ISO/TC 61 – Technical Committee for Plastics standards.

By following ISO 1600:1990 and referenced documents, organizations ensure standardized and reliable evaluation of transparent plastics, supporting compliance throughout the global plastics supply chain.