ISO 7622-2:2022

Overview

ISO 7622-2:2022 sets the international standard for testing the tensile strength of steel cords in conveyor belts with a steel carcass. This standard specifies the longitudinal traction test method, a destructive testing procedure used to determine the maximum tensile breaking strength of steel cords that make up the carcass of steel cord conveyor belts. It provides a clear, reproducible process tailored exclusively for conveyor belts reinforced with steel carcasses, ensuring consistent measurement and quality control.

The document applies primarily in scenarios where litigation is involved or when no manufacturer’s compliance certificate is available, supplementing ISO 7622-1, which covers elongation measurement.

Key Topics

• Test Methodology: The procedure involves preparing and conditioning test specimens cut from the conveyor belt, then subjecting the steel cords to a clinically controlled tensile test using appropriate dynamometric tensile testing machines.
• Test Specimens: Three types (A, B, and C) of specimens are described, each requiring precise preparation to isolate the steel cords for accurate tensile testing.
• Apparatus Requirements: Specifies machine capacities, rate of jaw separation (100 ± 10 mm/min), jaw types to avoid slippage, and specimen holding requirements.
• Conditioning: Test specimens must be conditioned per ISO 18573 to ensure consistent atmosphere (temperature and humidity) before testing.
• Tensile Strength Calculation: The tensile strength, expressed in newtons per millimeter (N/mm), is calculated using the breaking force and belt dimensions, providing a theoretical maximum tensile strength value.
• Test Reporting: Detailed reporting requirements include test specimen type, environmental conditions during testing, force measurements, and calculated tensile strength values.

Applications

• Quality Assurance in Manufacturing: Ensures steel cord conveyor belts meet strength requirements before shipment or installation.
• Failure Analysis: Provides an established testing method for investigating belt failures or disputes regarding belt strength.
• Material Research and Development: Assists manufacturers and researchers in evaluating new steel cord designs or rubber compounds for improved tensile strength performance.
• Regulatory Compliance: Supports compliance verification with contractual or industry requirements for conveyor belt tensile strength.
• Maintenance and Safety Checks: Enables plant operators and service professionals to assess long-term belt integrity and prevent operational downtime caused by belt failures.

Related Standards

• ISO 7622-1: Steel cord conveyor belts - Longitudinal traction test - Part 1: Measurement of elongation. This standard focuses on elongation measurement to complement the tensile strength assessment of ISO 7622-2.
• ISO 18573: Conveyor belts - Test atmospheres and conditioning periods. Defines conditioning environments critical for consistent tensile testing results.
• Other ISO 7622 series parts: Cover additional aspects of steel cord conveyor belt testing, important for a comprehensive belt evaluation.

Keywords: ISO 7622-2, steel cord conveyor belts, tensile strength test, longitudinal traction test, conveyor belt testing standards, steel carcass conveyor belts, dynamometric tensile testing, test specimen preparation, conveyor belt quality control, international standards for conveyor belts.