ASTM D7724-18(2023)e1 PDF

Overview

ASTM D7724-18(2023)e1 is an international standard published by ASTM, titled Standard Test Method for Carbon Black-Non-Dispersible Matter by Mechanical Flushing (NDM). This test method specifies procedures for determining the quantity of non-dispersible matter in regular untreated carbon blacks after mechanical water flushing. The presence of non-dispersible matter in carbon black is crucial for certain molded or extruded products, as it can directly impact surface appearance and quality.

The standard outlines the apparatus, sampling methods, and calculation procedures used to quantify non-dispersible matter. The results guide product specifications and quality assurance processes in industries relying on carbon black pigments and fillers.

Key Topics

• Test Scope and Limitations

  • Applicable to regular, untreated carbon blacks; not suitable for oil-treated grades, as oil hampers proper wetting by water.
  • Uses SI units exclusively to maintain consistency.
  • Does not specifically address safety, health, or regulatory concerns; users are responsible for compliance with relevant practices.

• Test Method Summary

  • A measured sample of carbon black is flushed with water through a specified wire-mesh sieve.
  • The non-dispersible matter remaining on the sieve is dried and weighed, and the amount is expressed in mg/kg (ppm).
  • The sieve size used for testing is agreed upon between the purchaser and manufacturer.

• Precision and Reporting

  • Provides guidance on repeatability and reproducibility based on round-robin testing.
  • Results must be properly identified with sample and sieve details, reported to the nearest mg/kg (ppm).

Applications

ASTM D7724 is mainly used in the carbon black manufacturing and processing industries, along with other sectors where carbon black is a key material. Key practical applications include:

• Quality Control of Carbon Black: Ensures batches have acceptable levels of non-dispersible particles, reducing risk of surface defects in final products.
• Production of Molded and Extruded Products: Critical for applications such as automotive components, plastic pipes, and hoses, where surface finish and uniformity matter.
• Supplier-Purchaser Agreements: Enables standardized testing results for contractual quality requirements between carbon black producers and end-users.
• Regulatory and Compliance Testing: Used by laboratories and manufacturers to demonstrate conformance to international product quality standards.

Testing in accordance with ASTM D7724 helps manufacturers minimize defects, enhance product performance, and build stronger assurance in the supply chain.

Related Standards

For comprehensive testing and quality evaluation, ASTM D7724 is often used alongside other key ASTM standards:

• ASTM D1799 – Practice for Carbon Black-Sampling Packaged Shipments
• ASTM D1900 – Practice for Carbon Black-Sampling Bulk Shipments
• ASTM D4483 – Practice for Evaluating Precision for Test Method Standards in the Rubber and Carbon Black Manufacturing Industries
• ASTM E11 – Specification for Woven Wire Test Sieve Cloth and Test Sieves

These related documents support effective sampling, evaluation, and quality control in carbon black handling and processing.

Keywords: ASTM D7724, carbon black, non-dispersible matter, mechanical flushing, quality control, molded products, extruded products, carbon black testing, ASTM standards.