A: For Cycle A (standard), a minimum of 40 hours, but moisture equilibrium may take longer (e.g., 4 days for thick nylon bars).
Implementing ASTM D618-21 in a testing workflow involves five critical steps:
To manage this variability, provides a standardized framework for preparing plastic specimens. Utilizing this standard ensures that tests conducted in different labs, or on different days, yield comparable results.
Explains why conditioning is necessary for data repeatability. astm d618-21 pdf
Used to simulate direct contact with water or fluid environments.
ASTM standards are copyrighted documents. To get an official, legal PDF of ASTM D618-21, you have three primary options:
In the realm of plastics manufacturing, engineering, and quality control, ensuring consistent and reproducible test results is paramount. Because many plastic materials are hygroscopic (they absorb moisture from the air) or thermally sensitive, their physical, electrical, and mechanical properties change based on environmental conditions. A: For Cycle A (standard), a minimum of
: As the name suggests, specimens are fully immersed in distilled water at 50°C ± 1°C for 48 hours. After immersion, they are cooled to 23°C for testing. This is used to evaluate the effects of water absorption on plastic materials.
ASTM D638 (Tensile), D790 (Flexural), D256 (Izod Impact)
This practice ensures that all plastic materials reach equilibrium in temperature and moisture before physical, mechanical, or electrical evaluation. Eliminating environmental variables allows laboratories worldwide to achieve consistent, repeatable results. Overview of ASTM D618-21 To get an official, legal PDF of ASTM
D618 Standard Practice for Conditioning Plastics for Testing
Two days later, he placed a conditioned sample into the tension tester. The machine whirred, pulling the plastic to its limit. Instead of a sharp crack , the material stretched, yielded, and held firm. The numbers on the screen matched the safety requirements perfectly.