Overview
ISO 811:2018, titled Textiles - Determination of resistance to water penetration - Hydrostatic pressure test, is an international standard published by the International Organization for Standardization (ISO). This standard specifies a hydrostatic pressure testing method to assess the water penetration resistance of fabrics. It applies to all textile fabrics intended to be water resistant, regardless of whether they have been treated with water-resistant or water-repellent finishes.
ISO 811:2018 provides a robust and reproducible approach to measuring how fabrics perform under water pressure, which is critical for evaluating water resistance in textiles used in outdoor apparel, protective clothing, upholstery, and technical textile products.
Key Topics
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Hydrostatic Pressure Method
The test measures the water pressure a fabric can withstand before water penetrates through it at three distinct points. The pressure is gradually increased while the fabric is subjected to water, and the point of penetration determines the fabric's resistance level.
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Applicable Fabrics
The standard covers all fabric types intended to resist water penetration, including untreated, water-resistant, and water-repellent textiles.
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Test Conditions
- Testing is conducted under strictly controlled atmospheric conditions in line with ISO 139.
- Water used must meet grade 3 quality as per ISO 3696, with the test conducted at either 20 °C or 27 °C.
- The water pressure can be applied from above or below the fabric, and this must be documented in the test report.
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Test Procedure Essentials
- Specimens are conditioned and clamped in a specialized fabric clamp ensuring no leakage or slippage.
- Water pressure increases steadily at specified rates (10 cm H₂O/min or 60 cm H₂O/min), with the rate explicitly noted in the results.
- Penetration is detected visually, and the pressure at which water first appears at three different points is recorded.
- Testing requires at least five specimens from different fabric areas to ensure representative results.
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Result Reporting
Results include individual and mean pressures causing water penetration, expressed in centimeters or millibars of water pressure. Detailed test conditions, specimen information, and any deviations are also included in the test report for transparency and reproducibility.
Applications
ISO 811:2018 is vital for industries and professionals involved in:
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Outdoor and Sportswear Manufacturing
Evaluating the water resistance of garments designed for rainwear, hiking, camping, and sports to ensure performance under wet conditions.
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Protective Clothing
Testing barrier fabrics for chemical protection, medical wear, and occupational safety garments where water penetration resistance is critical.
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Technical and Industrial Textiles
Assessing materials used in tents, tarpaulins, upholstery, and automotive textiles where water resistance impacts product durability and user comfort.
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Quality Control and Assurance
Using standardized test procedures to maintain consistent product performance and support product claims related to water resistance.
Related Standards
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ISO 139: Textiles - Standard Atmospheres for Conditioning and Testing
Defines the environmental conditions (temperature, humidity) required for proper conditioning and testing of textile materials.
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ISO 3696: Water for Analytical Laboratory Use - Specification and Test Methods
Specifies the required purity and testing for water used in laboratory analyses, ensuring consistent reagent quality during testing.
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ISO 2859-1: Sampling Procedures for Inspection by Attributes
Provides sampling plans useful for quality control when applying ISO 811 for broader product assessment or production lot inspection.
ISO 811:2018 is an essential reference for manufacturers, testing laboratories, and quality assurance professionals seeking to accurately assess and report the water penetration resistance of textiles. Its application helps ensure product reliability, performance, and compliance with international expectations for water-resistant textiles.