Overview
EN ISO 1600:1999 establishes an internationally recognized method for determining the light absorption of cellulose acetate plastics. The procedure measures changes in optical density when moulded specimens are produced with different periods of heating. With applications extending to other transparent, lightly colored plastics that can be moulded under the specified conditions, this standard helps manufacturers and laboratories assess material quality and the effects of processing variables on optical properties. The standard is widely referenced in the plastics and polymer industry for quality control and research.
Key Topics
- Scope and Applicability: Suitable for cellulose acetate with an acetic acid yield of 54% ± 2.5%. Other transparent, non-strongly colored plastics that can be moulded similarly may also be tested.
- Measurement Principle: Light absorption is characterized by recording optical density at two points - the blue (around 440 nm) and red (around 640 nm) ends of the visible spectrum. These data points suffice to profile the material’s light absorption properties.
- Sample Preparation: The standard outlines specimen preparation, including methods for incorporating plasticizers and detailed die moulding instructions.
- Variable Heating Cycles: Two sets of specimens are prepared - “initial light absorption” is measured from those using the minimal heating period; additional specimens are subjected to extended heating to determine changes in absorption after further processing.
- Calculation: Optical density at 25 mm specimen thickness is calculated using measurements from the absorptiometer, standardizing results for comparability.
- Reporting Requirements: Results must be reported with reference to this standard, including identification details of the tested product and the date of testing.
Applications
EN ISO 1600:1999 has significant practical value in various areas of the plastics industry:
- Quality Control: Used by manufacturers of cellulose acetate and similar thermoplastics to assess the optical clarity and consistency of their products.
- Material Certification: Provides a standardized approach for certifying materials that must meet specific light transmission or absorption criteria, ensuring materials are fit for use in optical applications.
- Process Optimization: Assists in evaluating how moulding conditions, especially heating periods, impact the visual and functional properties of plastics.
- Research and Development: Valuable in developing new transparent plastic formulations where control of optical density is critical.
- Comparative Testing: Allows laboratories to compare the effects of different processing methodologies on light absorption characteristics, supporting innovation in plasticizer incorporation and moulding techniques.
Related Standards
In conjunction with EN ISO 1600:1999, several standards are relevant for organizations dealing with transparent plastics and cellulose acetate:
- ISO 565: Specifies sieve mesh sizes, relevant for sample preparation.
- ISO 585: Describes determination of moisture content in unplasticized cellulose acetate, important for accurate specimen preparation.
- ISO 527: (Plastics - Determination of tensile properties) for broader mechanical assessment.
- ISO 11357: (Plastics - Differential scanning calorimetry) often referenced for understanding thermal properties in parallel with optical properties.
Employing EN ISO 1600:1999 ensures consistency and reliability in the measurement of light absorption in cellulose acetate and related plastics, supporting the production of materials with controlled transparency and color stability. Adhering to this standard aids compliance, enhances product reputability, and aligns with best practices in polymer quality assurance.
