ISO 75:2020 - Plastics — Determination of temperature of deflection under load

ISO 75 specifies methods for determining the temperature at which plastic materials deform under a specified load, known as the heat deflection temperature (HDT). This test evaluates the material's thermal resistance under mechanical stress.

Scope:

• Testing Methodology: Details procedures for subjecting plastic specimens to a bending load in a liquid or air medium with increasing temperature at a controlled rate.
• Load Specifications: Defines standard loads (1.80 MPa, 0.45 MPa, or 8.0 MPa) to simulate different stress conditions.
• Measurement Parameters: Measures the temperature at which the specimen reaches a specified deflection (0.25 mm).
• Material Applicability: Applicable to thermoplastics and thermosets, filled or unfilled, including composites.

Applications:

• Material Selection: Helps in selecting suitable plastics for applications requiring high-temperature performance.
• Quality Control: Ensures consistency in material performance during production processes.
• Performance Testing: Evaluates a material’s ability to maintain structural integrity under heat and load.
• Research and Development: Supports the development of plastics with enhanced thermal properties.