Overview
ISO 21179:2013 is an international standard published by the International Organization for Standardization (ISO) that specifies a standardized test method to determine the electrostatic field generated by a running light conveyor belt. This standard applies specifically to light conveyor belts as defined in ISO 21183-1 and addresses the dynamic measurement of the electrostatic field-a critical factor in evaluating the antistatic behavior of conveyor belts beyond static electrical resistance testing (ISO 21178).
This method ensures consistent and reproducible results for assessing electrostatic properties, which is essential for conveyor belt manufacturers, quality control laboratories, and industries where static electricity poses operational or safety risks.
Key Topics
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Scope and Purpose
ISO 21179:2013 focuses on measuring the electrostatic field generated dynamically by light conveyor belts during operation, reflecting real-use conditions better than static electrical resistance tests.
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Test Apparatus
The test setup includes:
- Electrically earthed steel pulleys (≥ 200 mm diameter, chromium-plated surface)
- Tensioning devices to achieve uniform loading on the belt
- A drive pulley to run the belt at 5 m/s
- Electrostatic field or surface potential measuring devices
- Recording equipment for capturing electrostatic field strength over time
- Earthed steel plates to correct and shield the electrostatic measurement
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Test Piece Requirements
- Endless belt samples (2,500 ± 50 mm length, 100 ± 1 mm width)
- New, uncontaminated, and conditioned under specified atmospheric conditions to ensure consistency prior to testing
- Endless joining performed according to manufacturer guidelines
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Procedure
The belt is run on the test apparatus with each side contacting the pulleys sequentially. Electrostatic fields or surface potentials are then recorded at a fixed measuring distance over a 30-minute period to capture maximum and stable values.
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Result Expression
Results include the maximum electrostatic field strength and a stable value when field change is less than 10% over 10 minutes. Surface potential can also be calculated from field strength based on the electrode distance. Arithmetic means can be used when multiple tests are performed.
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Test Reporting
Complete reporting includes:
- Belt material designation and manufacture date
- Modulus of elasticity (k value) of test piece
- Testing conditions (temperature, humidity, conditioning details)
- Shaft load applied and belt side tested
- Electrostatic field strength or surface potential values observed
- Reference to ISO 21179 with any exceptions noted
Applications
ISO 21179:2013 is crucial in various industrial sectors where control and understanding of electrostatic phenomena in conveyor belt systems are important:
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Manufacturing and Automation
Ensuring conveyor belts do not generate hazardous electrostatic discharge that could disrupt sensitive manufacturing processes or electronic equipment.
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Mining and Material Handling
Assessing belts for safety in environments where static sparks could ignite flammable dust or gases.
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Food and Pharmaceutical Industries
Monitoring static generation to prevent contamination or damage to products caused by static cling or particle attraction.
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Quality Control and Product Development
Enabling manufacturers to design and validate conveyor belts with appropriate antistatic properties, complying with international standards for static behavior.
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Safety Compliance
Supporting organizations in meeting regulatory requirements related to electrostatic discharge and workplace safety.
Related Standards
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ISO 21183-1: Principal characteristics and applications of light conveyor belts, providing the context and scope of belts tested under ISO 21179.
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ISO 21178: Determination of electrical resistances in light conveyor belts, focusing on static electrical resistance measurements.
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ISO 18573: Test atmospheres and conditioning periods for conveyor belts to ensure consistency in testing conditions.
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ISO 21181: Determination of the relaxed elastic modulus for light conveyor belts, relevant for setting test piece tensioning parameters.
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ISO 4287: Surface texture profiling, applied here for ensuring pulley surface roughness in the test apparatus complies with prescribed tolerances.
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ISO 22: Specification for flat transmission belts and pulleys, referenced for pulley dimensions and crowning to achieve uniform belt tension.
Keywords: ISO 21179, electrostatic field measurement, light conveyor belts, antistatic testing, electrostatic discharge, conveyor belt testing standard, electrostatic safety, conveyor belt quality control, electrostatic field strength, surface potential measurement.
Open preview (PDF)Light conveyor belts — Determination of the electrostatic field generated by a running light conveyor belt