Overview
ASTM D185-07(2023) - Standard Test Methods for Coarse Particles in Pigments establishes procedures to determine the presence and quantity of coarse particles in dry pigments, particularly those larger than 45 micrometers (μm). This standard is essential for quality control in paint and coating manufacturing, ensuring the smoothness of finished paint films by identifying pigment agglomerates or undispersed coarse particles that could negatively impact film texture and performance.
The test methods described are integral for grading raw materials used in industrial coatings, paints, and other applications where pigment dispersibility and uniformity are critical.
Key Topics
- Coarse Particle Detection: The standard covers methodologies for isolating and quantifying coarse particles in pigment samples, focusing on particles larger than 45 μm.
- Quality Control in Pigment Production: Utilizes precise procedures to assure pigment quality, preventing defects in paint films due to undispersed, oversized particles.
- Sieve Analysis: Prescribes the use of a 45 μm (No. 325) test sieve conforming to ASTM E11, ensuring consistency and repeatability in testing.
- Sample Preparation and Handling: Details best practices for weighing, dispersing, sieving, and collecting retained material to avoid sample loss and ensure accurate results.
- Safety and Compliance: Reminds users to establish proper safety, health, and environmental protocols while adhering to relevant local regulatory requirements.
Applications
The procedures outlined in ASTM D185-07(2023) are widely applied in:
- Paint and Coating Manufacturing: Ensuring raw pigment quality to achieve smooth, defect-free paint films by detecting and grading out pigments with unacceptable levels of coarse particles.
- Pigment Supply Chain: Used by pigment producers and suppliers as a quality assurance tool, facilitating compliance with stringent customer specifications.
- Research and Development: Supports formulation scientists and chemists in evaluating new pigment sources or optimizing dispersion processes for innovative coatings and paints.
- Industrial and Commercial Quality Assurance: Serves as a reference method for inspection and certification labs assessing batch-to-batch pigment consistency.
By implementing this standard, manufacturers and suppliers can minimize product defects such as roughness, poor coverage, or compromised durability caused by coarse pigment agglomerates.
Related Standards
- ASTM E11 - Specification for Woven Wire Test Sieve Cloth and Test Sieves: Defines the requirements for sieves used in the coarse particle determination procedure.
- ASTM D01 Series: Encompasses additional test methods and standards for paints, pigments, and related coatings, materials, and applications.
- International Standards Relevant to Pigment Testing: The content of ASTM D185 aligns with global principles, including those set by the World Trade Organization Technical Barriers to Trade (TBT) Committee, facilitating international acceptance and harmonization.
Practical Value
Adhering to ASTM D185-07(2023) enables organizations to:
- Maintain consistent product quality and compliance with global standards
- Reduce the risk of product recalls or customer complaints related to surface finish
- Optimize raw material selection and manufacturing processes for higher efficiency and yield
- Enhance reputation in domestic and international pigment and paint markets
Keywords: coarse particles, pigments, agglomerates, quality control, sieve analysis, paint smoothness, ASTM D185, pigment grading, industrial coatings, test methods