Overview
EN ISO 22776:2004 is a European and international standard specifying a test method for the longitudinal shear strength of touch and close fasteners (commonly known as hook-and-loop fasteners) used in footwear and related accessories. This standard provides a precise framework to measure the shear strength of fasteners both before and after repeated use, ensuring durability and performance in footwear applications.
Developed by the European Committee for Standardization (CEN) in collaboration with ISO Technical Committee TC 216 (Footwear), the standard is applicable across all member countries of CEN, enabling consistent quality assessment of fasteners to guarantee product reliability.
Key Topics
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Scope
Defines testing for the longitudinal shear strength of touch and close fasteners prior to and after repeated opening and closing cycles.
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Terminology
Clarifies key terms such as:
- Longitudinal shear strength - maximum force per unit area required to separate fastener tapes.
- Effective width - useful width of the fastener tape excluding edges.
- Effective area - the product of effective width and length of overlap.
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Test Principle
Determines shear strength by separating mated tapes at a constant rate parallel to their length, simulating real use scenarios.
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Apparatus Required
- Tensile testing machine capable of precise jaw separation rates.
- A roller device to apply standard closing pressure on fasteners before testing.
- A touch and close cycling machine to perform repeated opening and closing for durability testing.
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Test Specimen Preparation
Detailed methods for cutting, marking, and conditioning specimens under standard atmospheres before testing.
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Test Procedure
- Measuring effective width according to EN 12240.
- Overlapping hooks and loops with specified lengths depending on tape type.
- Applying roller pressure and using the tensile machine to measure maximum force required to shear fastener.
- Cycling fastener repeated opening and closing (5,000 rotations) to evaluate shear strength degradation.
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Calculation of Results
Shear strength is expressed in newtons per square centimeter (N/cm²), calculated from measured force divided by effective closure area.
Results include minimum, maximum, and mean shear strengths with noted failure modes.
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Reporting Requirements
Includes all relevant test conditions, specimen details, calculated strengths, modes of failure, deviations, and test dates for comprehensive documentation.
Applications
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Footwear Industry
Ensures quality and durability for touch and close fasteners on shoes, boots, and orthotic devices, crucial for consumer safety and product performance.
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Accessory Testing
Applicable to accessories equipped with hook-and-loop closures such as bags, protective gear, and sports equipment.
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Quality Control and Product Development
Helps manufacturers assess design robustness and fastener lifespan under real usage conditions, guiding improvements.
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Regulatory Compliance
Meets international demands by harmonizing test methods across European and global markets, facilitating trade and standard adherence.
Related Standards
- EN 12222 – Standard atmospheres for conditioning and testing footwear and components, ensuring consistent environmental conditions during testing.
- EN 12240 – Determination of the overall and effective widths of touch and close tapes, important for accurate test specimen measurement.
- EN ISO 7500-1 – Verification and calibration of tensile testing machines used for force measurement, ensuring accuracy in test results.
Summary
EN ISO 22776:2004 provides a standardized, reliable procedure to evaluate the shear strength durability of touch and close fasteners before and after repetitive use in footwear applications. By following this method, manufacturers and quality assurance teams can ensure fasteners maintain their functional integrity over time, enhancing product safety and consumer satisfaction in the footwear and accessories market. This standard plays a critical role in maintaining consistent product performance, supporting quality management, and fostering international harmonization of footwear testing methods.