ASTM D2210-21 PDF

Overview

ASTM D2210-21: Standard Test Method for Grain Crack and Extension of Leather by the Mullen Test is an internationally recognized ASTM standard that specifies a reliable method for determining the resistance of light leather materials to grain cracking and measuring their extension properties. Using controlled hydraulic pressure via the Mullen Test, this method ensures manufacturers, quality control laboratories, and buyers can evaluate the durability and performance of leathers such as those used in shoe uppers, garments, gloves, and upholstery.

By applying pressure to the flesh side of a leather specimen, this standard assesses the force required to crack the grain and quantify leather extension. The data supports quality assurance, specification compliance, and ongoing manufacturing control.

Key Topics

• Hydraulic Pressure Testing: Explains the use of steady hydraulic pressure to stress leather specimens until grain cracking occurs.
• Measurement of Extension: Informs on measuring the stretch (extension) of leather at various loads or at grain failure to evaluate lasting stress resistance.
• Apparatus and Specimens: Describes equipment such as the Mullen tester, diaphragms, dial gauges, and specimen size selection.
• Result Interpretation: Highlights methods for calculating cracking pressure, stretch (as percentage), thickness, and pumping rate.
• Precision and Repeatability: Outlines criteria for consistent results within and between laboratories, enhancing test reliability.
• Exclusions and Limitations: Specifies that this method is for light leathers (not wet blue or wet white) and that defects like cuts or scratches will influence results.
• Safety Responsibilities: Reminds users to address all safety, health, and environmental concerns and adhere to regulatory requirements.

Applications

ASTM D2210-21 is widely applied in sectors that require assured leather quality and durability, including:

• Footwear and Accessories: Helps test shoe uppers and gloves for resistance to cracking and adequate extension, vital for wear and comfort.
• Upholstery: Supports assessment of upholstery leather's ability to withstand stretch and stress without surface cracking.
• Garment Leathers: Ensures garment leathers have appropriate extension and strength for lasting use.
• Manufacturing Quality Control: Enables producers to monitor production consistency, identify batch variations, and control input material quality.
• Specification and Contract Acceptance: Offers clear criteria for accepting or rejecting leather lots based on standardized testing.
• Research and Development: Aids in developing new leather materials or finishes with targeted performance characteristics.

Related Standards

When employing ASTM D2210-21, the following referenced ASTM standards frequently support or complement the test procedure:

• ASTM D1610: Practice for Conditioning Leather and Leather Products for Testing - essential for sample preparation and consistency.
• ASTM D1813: Test Method for Measuring Thickness of Leather Test Specimens - ensures accurate measurement of specimen thickness prior to testing.

Keywords: leather testing, grain crack, Mullen test, ASTM D2210, leather extension, hydraulic pressure, lasting property, quality control, light leathers, footwear, glove leather, upholstery leather.

Summary: ASTM D2210-21 is an authoritative standard that ensures precise evaluation of the grain crack resistance and extension properties of light leathers, facilitating quality assurance throughout the leather industry. Its adoption enhances confidence in leather performance for both manufacturers and consumers.