Without standardizing the ambient conditions prior to testing, comparing material data sheets from different manufacturers becomes impossible.
ASTM D618-21 is a standard practice established by ASTM International
Once conditioning concludes, test the specimens immediately. If they must leave the chamber before testing, they should be stored in a desiccator or sealed poly bag and tested within 30 minutes. ISO 291 vs. ASTM D618-21
ASTM D618-21 PDF: Standard Practice for Conditioning Plastics for Testing astm d618-21 pdf
: This is the most common method. It uses an environmental chamber set to 23°C and 50% relative humidity. The conditioning time depends on thickness: 40 hours for specimens ≤7 mm and 88 hours for those >7 mm. This method is best for general testing and routine quality control.
The ASTM D618-21 standard is significant because it provides a standardized approach to conditioning and testing plastics. This helps to ensure that test results are consistent and comparable across different laboratories and testing facilities.
, titled "Standard Practice for Conditioning Plastics for Testing," is the definitive guide used to control these environmental factors before and during testing. What is ASTM D618-21? ISO 291 vs
: This method conditions specimens at 23°C and 96% relative humidity for a specified time. It’s useful for applications where plastics will be used in consistently damp environments.
Users of the standard should be aware of its relationship with its international counterpart. ASTM D618-21 explicitly notes a technical difference in Note 1: "This standard and ISO 291 address the same subject matter, but differ in technical content. , or both". ASTM D618-21, in contrast, offers a broader set of procedures, providing more flexibility for a wider range of plastic types and testing scenarios.
Tell you which are most sensitive to these conditions List related ASTM standards for testing The conditioning time depends on thickness: 40 hours
Plastics are surprisingly sensitive. Their physical and electrical properties can shift dramatically with changes in temperature and humidity, directly impacting test results in a way that makes reliable comparisons difficult. To solve that, was created—it’s the standard practice for conditioning plastics before testing.
The 2021 update (ASTM D618-21) keeps the fundamental principles of previous versions (such as D618-13 or D618-08) while ensuring the document remains up-to-date with current industry needs.
This is the most widely utilized procedure for general-purpose plastics testing [1]. Specimens thick are conditioned at RH for a minimum of 40 hours [1]. Specimens thicker than require a minimum of 88 hours.
When sourcing the official , laboratories must ensure compliance with international copyright regulations:
ASTM D618-21 is a and is not legally available for free public distribution. The 2021 edition is the current active version, and as of early 2024, a new revision was in development (work item WK94270), highlighting the standard's continued evolution.