ASTM D6020-00(2020)

Overview

ASTM D6020-00(2020), Standard Practice for Calculation of (Non-Mineral) Combined Tanning Agents and Degree of Tannage, is an internationally recognized guideline developed by ASTM International. This practice outlines procedures for determining the combined levels of tannin and nonextractable organic resins, as well as the degree of tannage in vegetable-tanned leather and leather incorporating organic retannages. The standard plays a critical role in quality control and product assessment in the leather industry, particularly for vegetable-tanned materials. Note that ASTM D6020-00(2020) does not apply to wet blue leathers.

Key Topics

• Combined Tannin Content: Provides methodologies to quantify tannins and nonextractable organic matter, such as vegetable tannins and acrylic lubricants, that are not removed by water or hexane extractions.
• Degree of Tannage: Offers calculations to determine how thoroughly leather has been tanned, thereby reflecting its structural and performance characteristics.
• Reference Methods: Relies on supporting ASTM test methods (D2868, D2875, D2876, D3495) for quantifying key constituents, such as water-soluble materials, chloroform-soluble substances, insoluble ash, and hide substance.
• Reporting Standards: Specifies reporting requirements for combined tannin percentages (to the nearest 0.1%) and degree of tannage (to the nearest 0.5°), ensuring consistency and traceability.
• Applicability and Limitations: Designed for vegetable-tanned and organically retanned leathers, this standard is not suited for leathers produced with mineral tanning methods such as wet blue.

Applications

The practical applications of ASTM D6020-00(2020) include:

• Leather Quality Control: Used extensively by tanneries and laboratories to verify the presence and levels of non-mineral tanning agents in leather products.
• Material Compliance: Supports manufacturers and suppliers in meeting regulatory and product performance requirements, particularly for vegetable-tanned leather goods.
• Product Development: Facilitates research and development by enabling precise monitoring of organic tanning agent integration, which can impact flexibility, durability, and final product performance.
• Performance Verification: Assists in comparing batches or alternative tanning processes by quantifying the degree of tannage, aiding in process optimization and quality assurance.
• Trade and Procurement: Provides a standardized basis for specifying and accepting vegetable-tanned leather, enhancing trust among producers, buyers, and regulatory agencies worldwide.

Related Standards

For comprehensive testing and evaluation in alignment with ASTM D6020-00(2020), the following related ASTM test methods are referenced:

• ASTM D2868: Test Method for Nitrogen Content (Kjeldahl) and Hide Substance Content of Leather, Wet Blue and Wet White
• ASTM D2875: Test Method for Insoluble Ash of Vegetable-Tanned Leather
• ASTM D2876: Test Method for Water-Soluble Matter of Vegetable-Tanned Leather
• ASTM D3495: Test Method for Hexane Extraction of Leather

These standards provide foundational procedures for measuring the specific parameters necessary to implement the practice outlined in ASTM D6020-00(2020).

ASTM D6020-00(2020) is crucial for any organization engaged in the production, processing, or analysis of vegetable-tanned leather, ensuring standardized, reliable assessment of tanning agents and promoting international consistency in the characterization of leather materials.

Keywords: combined tannins, degree of tannage, leather quality control, tannin analysis, vegetable-tanned leather, ASTM leather standards, organic tanning agents