The standard acknowledges that some specific plastic materials may have their own detailed specification that references ASTM D618-21 but with certain modifications. In such a case, the material's own specification takes precedence over this standard.
This standard is a critical quality control tool for the global leather supply chain: Durability
: It provides a scientific basis for assessing the overall strength and durability of the leather coating, simulating wear-and-tear such as the creases formed during walking. Unuo Instruments Technical Methodology The test utilizes a specialized machine called a Bally Flexometer to simulate repeated bending. iTeh Standards Apparatus and Calibration : The Bally Flexometer must operate at a rate of cycles per minute Specimen Preparation : Samples are typically cut to astm d61821 pdf
The test can be conducted in two main ways to simulate different environments:
Because the molecular structure of polymers is highly sensitive to ambient temperature and atmospheric moisture, skipping or altering the conditioning phase invalidates standard testing. Authentic copies of the document can be searched and officially acquired via the ASTM International D618-21 Product Page. Why Conditioning Matters in Plastic Testing Unuo Instruments Technical Methodology The test utilizes a
48 hours at 50 ± 3 °C followed by direct water immersion at 23 °C.
To maintain the integrity of these procedures, ASTM D618-21 mandates strict control over the laboratory environment: : Defined as relative humidity. Why Conditioning Matters in Plastic Testing 48 hours
The values stated in SI units are to be regarded as standard. The Testing Procedure
Water immersion at 50°C for 48 hours, then cooled to 23°C before testing. Procedure D: High humidity conditioning (96% RH at 23°C). Notation and Technical Details
This test method covers the determination of the extractable content of plastic materials, including: