Hydrostatic Head Tester Test Method

Hydrostatic Head Tester

Waterproof textile performance testing --- Hydrostatic Head Tester Test Method

Main content:

1. Preparation of performance factors waterproof and breathable fabric, principles and influence;

2. Domestic and international water-repellent fabric performance testing standards;

3. Hydrostatic testing methods;

4. Hydrostatic testing method ---- Hydrostatic Head Tester

The so-called water-resistant outer fabric means that water will not penetrate the fabric, and it will not be dipped the inside, also known as surface moisture resistance. Waterproof and breathable textile is a new high-grade fabrics more important category, the rapid development in recent years, the most popular. For example: Gore-Tex (GORE-TEX) fabrics, from the United States WLGore & Associates, Inc. (Gore) invented and produced an exclusive, thin, strong and durable film, it has a waterproof, breathable and weather-resistant, which succeeded in break through the general fabric breathable waterproof shortcomings, it is known as the "century of the cloth"

GORE-TEX fabrics and Waterproofing Principle

I. A kind of fabric waterproof

Preparation for Fabric waterproof

General cotton, viscose, silk and linen and other more polyester, nylon, polypropylene and other fiber absorbent, if the requirement that they have a high level of water resistance to water for a variety of appliances, it must be waterproof or water repellent.

Waterproof explanation fact often including the "water-repellent" meaning. According to different properties of the fabric surface finishing, it can be distinguished, can basically be divided into two categories: one is waterproof but airtight finishing. It is a uniform coating on the fabric surface layer of impermeable, water-insoluble coating, finishing the fabric pore blockage, preventing water and air through the fabric, which is also known as finishing coating finish (waterproof finishing). Such as polyurethane resin, polypropylene alcohol resins, rubber, tung oil and other treatment, the fabrics is not only impermeable and airtight, and feel too hard, it is not suitable for articles of clothing, generally applicable to industrial fabrics or outdoor. The other is waterproof and breathable finishing, also known as water repellent finish. This refers to textile finishing, finishing agents change the surface properties of the fibers, hydrophilic fibers into a hydrophobic surface, the fabric is not easy to be wetted, but still breathable, soft, commonly used in the production of clothing, raincoats and other fabric.

Waterproof, water repellent principle

FIG γL and γS represent the surface tension of liquids and solids, γLS represents the interfacial tension between the solid solution 2, θ is called the touch angle. When θ> 90 °, the liquid does not wet the solid surface; when θ <90 °, the liquid portion of the wet solid surfaces. Water repellent finishing requirements θ angle the bigger the better. Various fiber materials for water contact angle data vary widely, generally the order of: viscose <acrylic cotton ≈ <nylon <wool <polyester <polypropylene. Viscose good wet ability, polyester poor wet ability.

Affecting Factors of Fabric waterproof properties

There are many factors affected textiles of Waterproof performance, such as the material itself and textile craft production processes and technical issues, which will have implications, High or low Fabric waterproof performance index is decided by the following factors aspects

The thickness of the fabric:  The thicker the fabric, the greater the dampness, the greater the water pressure resistance values.

Yarn thickness:  For good absorbent fibers woven into the fabric tightly, since the presence of the capillary effect, reducing the radius of the yarn. Can improve fabric resistance to water

Tightness of the fabric:  The distance between the yarn increases will directly affect the level of water pressure resistance. Usually the fabric structure more closely, the better the performance of its water impermeability

Coating membrane pore size: Membrane pore size the greater the hydrostatic pressure, the worse the performance of coated fabrics

The size of the contact angle θ:  When θ> 90. the fabric has water repellent properties, with the increase of θ, the water pressure resistance values corresponding increase in fabric

Coating thickness: The coating is too thin, hard surface coating agent in a continuous deposition, reduced ability to withstand water pressure coated fabrics; pressure-resistant thick coating capability, improved fabric

Weft yarn performance is good or bad: Action by the water pressure, good flexibility and easy weft yarn elongation, resulting in the formation of a gap adjacent warp and weft, which drops easily seep through, making the fabric water pressure resistance values decrease

Coating quality: Require that the entire cloth uniform, with a certain fastness. With better the quality of coating, the better performance of water permeability.

First, the water resistance test standard

Presently, domestic and international standards for fabric waterproof properties are the following:

China National Standard

GB/T 4745-1997《Textile fabrics-Determination of resistance to surface wetting-Spray test》

GB/T 4744-1997《Textile fabrics-Determination of resistance to water penetration-Hydrostatic pressure test》

GB/T 14577-1997《Determination of water repellency of textile Bundesmann rain Act》

China Industry Standards

FZ/T01004-1991《Test Method for coated fabrics resistance to water penetration (Hydrostatic Testing)》

International standard

ISO 4920:1981《Textile fabrics - Determination of resistance to surface wetting spray test》

ISO 811:1981《Textile fabrics-Determination of resistance to water penetration-Hydrostatic pressure test》

ISO 1420:1987《Rubber and plastic coated fabrics - Determination of resistance to water hydrostatic pressure test》

Japanese standard：

JIS L-1092《Textiles hydrostatic water resistance test A》

American Association of Textile Chemists and Colorists standard

AATCC21-83《Water repellency -water repellency test method》

AATCC76-83《Water repellency -Dynamic water absorption test method》

AATCC-22:1996《Textile fabrics waterproof test: spray test》

AATCC22-2001 《Water Repellency: Spray Test》

AATCC35-2000《Water Resistance: Rain Test》

AATCC42-2000《Water Resistance: Impact Penetration Test》

AATCC127-2003《Water Resistance: Hydrostatic Pressure Test》

American Standard

ASTM D751-95《Coated fabrics- water resistance Test》

ASTM D3393《Standard Specification for Coated Fabrics—Waterproofness》

German standards

DIN 53888 《Determination of water repellency of fabrics Bundesmann rain Act》

EN 20811-1992 《Textile fibers - Determination of water penetration Hydrostatic pressure test》

EN 24920-1992 《Textiles - Determination of wetting the fabric surface resistance (spray test)》

Hydrostatic Head Tester Test Method

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Fabric waterproof testing, it is divided into 3 kinds such as field testing, simulations and laboratory testing.

Less cost on laboratory testing, time is short; the results can be obtained relatively, more practical. The main methods include hydrostatic test, spray test and water absorption experiments. Wherein the hydrostatic pressure indicator is one of the most important indicators of fabric waterproof, make the following detailed description as below,

Hydrostatic Head Tester

Test principle: dynamic testing, static testing and custom procedural law test for detecting water-repellent properties of textiles under a certain pressure. The sample is fixed on the standard test area by air compressor will 0-5bar distilled water added to a full tank, the tank directly connected to the test head, a certain amount of pressure delivered to the sample. When the pressure curve shown in real time on the operator screen, built-in a variety of testing standards, in order to convenience for user-friendly.

Hydrostatic Head Tester Technical Parameters:

 1. Testing pressure: 0-5000mbar (5000cmW.G);

 2. Testing precision: Resolution with 0.1mbar;

 3.Testing area: 100cm（10cm,19.63cm,26cm,28cm optional）;

 4. Rising rate of pressure: choose according to the standard also can input the specified value;

 5. Testing units for option: mbar/kPa/Pa/cm w.c /mm w.c;

 6. Maximum thickness of sample: 40mm;

 7. Compressed air: 6-8 bar (clean and dry air);

 8. Alarming time: 0- 9,999 min (also can be set up according to pressure or time);

 9. Pneumatic clamps. 

Product Information of Hydrostatic Head Tester:

 1. Multi-point touch operating system with capacitive color touch screen of 7-inch, easy for controlling. Test results can be saved to Excel file, and sent via WIFI to anywhere, can also be saved to the SD card.

 2. Simple and convenient test fixture is designed to provide superior gripping force, ensuring that the water does not leak out from the side edge even in high pressure.

 3. Automatic water supply, could provide a self-adding to test the specified position by means of built-in water level sensor,;

 4. High-precision pressure sensors and pressure control system, with high precision and broad test range;

 5. Multiple pressure units for selection (mbar/kPa/Pa/cm w.c/mm w.c), meet different requirements and the actual need;

 6.Selectable rate of pressure according to the standard data, or by user custom (if the pressure is beyond the maximum limit of 5000 mbar, the system will remind with pressure exceeding to ensure the safety in operation);

 7. Pressure alarm or time alarm could be set to save the observation time for operators, audible alarm when reaching the alarm conditions;

 8. In addition to the internal standard, the user can also choose the custom mode to set parameters for testing;

 9. LED soft illumination system, digitally adjust the lighting brightness;

 10. Test software configured with a variety of test standard, user-friendly;

 11.With powerful PC software for optional, and the function of test video playback,synchronized in the test data, pressure curve, and video, accurately detecting the water drops to measure pressure of the cloth, completely making an elimination of the observation error on human eyes.

Hydrostatic Head Tester Testing Standards:

 GB/T 4744, AATCC 127, ERT 120-1/160-0, BS EN 20811/3321/3424, AFNOR G07-057, ISO 811, JIS L1092A, JIS L1092.B-a, JIS L1092 B-b, ASTM F903C, ASTM F1670, ASTM F1671, EN 1734, ISO 1420, FZ/T 01004

Hydrostatic Head Tester Applications:

Hydrostatic Head Tester is designed to determine the waterproof property of outdoor wears, umbrella, and waterproof fabric. It is also used to test the resistance of permeability of synthetic blood for materials used in protective clothing. Dynamic, static, custom mode for different test requirements. One side of the specimen is subjected to a hydrostatic pressure that increasing at a constant rate, then will be ended until three points of leakage appear on its other side. The instrument contains a high precision pressure control system, which could produce the test pressure in an internal water tank. Real-time pressure curve displays on the screen.

Hydrostatic Head Tester Basic configuration:

 1. Hydrostatic Head Tester;

 2. 100 cm 2 Test Head;

 3. Analysis software;

 4. A set of PC test software (optional).

For more details see: http://www.qinsun-lab.com/Products/hydrostatic-head-tester.html# You can follow as below, Qinsun Instruments Co., LTD, Address: No. 258 Banting Road, Shanghai, Zip Code: 201199Phone: +86-21-6420 0566 Fax: +86-21-6420 0566-810 E-mail: info@qinsun-lab.com    website: www.qinsun-lab.com.