ASTM D968-22 PDF

Overview

ASTM D968-22 - Standard Test Methods for Abrasion Resistance of Organic Coatings by Falling Abrasive defines laboratory procedures for measuring the abrasion resistance of organic coatings applied to rigid surfaces, such as metal or glass panels. Developed by ASTM International, this standard plays a vital role in assessing the durability of coatings exposed to wear in industrial, commercial, and institutional settings. It covers two distinct test methods using different abrasives-falling sand and falling silicon carbide-to simulate real-world abrasive forces and provide insights into the protective qualities of various coating systems.

Key Topics

• Purpose of the Standard: ASTM D968-22 focuses on quantifying the abrasion resistance of organic coatings, which is essential for understanding their performance in environments exposed to physical wear and tear.

• Test Methods:

  • Method A – Falling Sand Abrasion Test: Utilizes naturally graded silica sand as an abrasive to determine the volume of sand required to wear through a coating.
  • Method B – Falling Silicon Carbide Abrasion Test: Uses graded silicon carbide, a more aggressive abrasive, better simulating harsher service conditions such as those experienced by ship deck coatings.

• Interpretation of Results: The amount of abrasive required to wear through a specific coating thickness (measured in litres or kilograms per micrometer) is reported as the abrasion resistance value. Results are most reliable within a single laboratory and are especially useful for comparative ranking of multiple coatings rather than producing highly reproducible numerical values across laboratories.

• Significance of Abrasive Choice: Silica sand produces a slower rate of abrasion and can provide finer differentiation between coatings, especially for flooring and similar applications. Silicon carbide offers a faster, more aggressive abrasion, suitable for heavy-duty environments.

• Lab Practices and Limitations: Due to the variability inherent in abrasive testing, ASTM D968-22 recommends using ranking systems rather than absolute values for interlaboratory comparisons. Consistent preparation, application, and environmental control are critical for reliable results.

Applications

ASTM D968-22 is widely used in the coatings and materials industry to evaluate the abrasion resistance of paints and protective finishes. Typical practical applications include:

• Quality control and product development: Manufacturers use these test methods to benchmark new coating formulations and ensure compliance with durability specifications.
• Specification compliance: Specifiers and procurement professionals can reference results from these tests to validate coating performance for flooring, ship decks, machinery, automotive parts, and architectural surfaces.
• Research and comparative analysis: Laboratories and research institutes use ASTM D968-22 to compare different coatings and select suitable products for aggressive service environments.

Using this standard helps industries select coatings based on measured performance under simulated wear conditions, supporting longer-lasting, cost-effective, and safer products.

Related Standards

For a comprehensive evaluation of coatings, ASTM D968-22 often works in conjunction with these related standards:

• ASTM D16: Terminology for Paint, Related Coatings, Materials, and Applications
• ASTM D823: Practices for Producing Films of Uniform Thickness on Test Panels
• ASTM D1005: Measurement of Dry-Film Thickness Using Micrometers
• ASTM D7091: Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings
• ASTM E11: Specifications for Woven Wire Test Sieve Cloth and Test Sieves
• ANSI B74.12: Specification for Abrasive Grain Size
• FEPA Standard 42-2: Grains of Fused Aluminum Oxide, Silicon Carbide, and Other Abrasives

Practical Value

Using ASTM D968-22 ensures reliable, repeatable testing of abrasion resistance for paints and coatings, supporting informed choices in product development, procurement, and quality control. By following these standardized methods, manufacturers and end-users can optimize coating selection for durability in demanding applications, reducing maintenance costs and enhancing product lifespan. This test method is recognized internationally, forming an important part of the quality assurance process for abrasion-resistant coatings.