In today’s global market, Consumers expect more from fabrics than just comfort and appearance. Especially in outdoor, Technical, and military applications, water resistance has become a critical performance indicator. To ensure quality, durability, and user protection, manufacturers turn to standardized testing methods to evaluate fabric performance under simulated rain conditions. One of the most effective and widely accepted methods is the use of a rain test apparatus for textiles.
The rain test apparatus for textiles plays an essential role in determining how well a fabric resists water penetration under simulated rainfall. Two of the most recognized international standards used for such testing are ISO 22958 and AATCC 35, which outline strict protocols for rain resistance testing. In this article, We Will explore the principles, standards, testing procedures, and equipment involved in textile water resistance testing. We’ll also introduce a reliable solution: the rain tester developed by Wewon Environmental Chambers Co., Ltd., designed specifically to meet these stringent requirements.
| Equipment Name: Rain Test Apparatus for Textiles | Equipment Model: WEW-RTA-AATCC 35 |
| 7 Pressures: 610mm, 915 mm, 1220 mm, 1525 mm, | 7 Pressures: 1830 mm, 2135mm, 2440 mm; |
| Stainless steel tank｜Transparent water column observation. | Pressure point can be adjusted manually｜Adjustable flow rate. |
| Nozzle diameter: 0.99 ±0.013mm | Test sample size: 200x200mm |
| Outer diameter of small hole/mm: 32.24 ±0.5 | Inner diameter of small hole/mm: 18.26 ±0.5 |
| Sample clamping width: 152mm ±1mm | Distance from nozzle to sample clamping surface/mm: 305 ±1 |
| Sample clamping spacing: 165mm (GB/T 23321) | 155mm (AATCC 35, ISO 22958) |
| Sample clamping size: 178 x 279 mm | Sample clamping spacing: 305mm |
| 1.1 This test method is applicable to any textile fabric, which may or may not have been given a water-resistant or water-repellent finish. It measures the resistance to the penetration of water by impact, and thus can be used to predict the probable rain penetration resistance of fabrics. | 1 Purpose and Scope | AATCC TM35 Test Method 35 |
| It is especially suitable for measuring the penetration resistance of garment fabrics. With the instrument, tests may be made at different intensities (see l1.1) of water impact to give a complete overall picture of the penetration resistance of a single fabric or a combination of fabrics. | ||
| 1.2 The results obtained with this test method depend on the water repellency of the fibers and yarns, and on the construction of the fabric. | ||
| 2.1 A test specimen, backed by a weighed blotter, is sprayed with water for 5 min under controlled conditions. The blotter is then reweighed to determine the amount of water which has leaked through the specimen during the test. | 2 Principle | |
| 3.1 water resistance, n. of fabric, the characteristic to resist wetting and penetration by water. (See also water repellency.) | 3 Terminology | |
| NOTE: These safety precautions are for information purposes only. The precautions are ancillary to the testing procedures and are not intended to be all inclusive. It is the user’s responsibility to use safe and proper techniques in handling materials in this test method. Manufacturers MUST be consulted for specific details such as material safety data sheets and other manufacturer’s recommendations. All OSHA standards and rules must also be consulted and followed. | 4 Safety Precautions | |
| 4.1 Good laboratory practices should be followed. Wear safety glasses in all laboratory areas. | ||
| 5.1 AATCC Rain Tester (see Figs. 1,2 and 3 and 11.3). | 5 Apparatus and Materials | |
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| 5.2 WhiteAATCC Textile Blotting Paper (see 11.4). | ||
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| 6.1 A minimum of three specimens of 20 x 20 cm is cut from the test fabric. The fabric samples and the blotting paper should be conditioned in an atmosphere of 65 ± 5% RH and 21 ± 2℃ (70 ± 4°F) for at least 4 h before testing. | 6 Test Specimens | |
| 7.1 The test specimen (see I1.5), backed by a 15.2 x 15.2 cm standard paper blotter weighed to the nearest 0.1 g is clamped in the specimen holder and the assembly is mounted in a vertical rigid support frame. The specimen assembly is positioned into the central portion of the spray at a distance of 30.5 cm from the face of the spray nozzle (see 11.6). A horizontal water spray at 27 + 1°C (81 + 2°F) (see 11.2) is directed against the specimen and is allowed to continue for a period of 5 min. At the end of the spray period the blotter is carefully removed and quickly reweighed to the nearest 0.1 g. | 7 Procedure | |
| 8.1 Water penetration as indicated by the increase in mass of the blotting paper during the 5 min test period is calculated, and the average for the three test specimens is reported. Individual determinations or average values of over 5.0 g may be simply reported to 5 + g or > 5 g | 8 Evaluation | |
| 8.2 In order to obtain a complete overall picture of the penetration resistance of a fabric or fabric combination the average penetration with different pressure heads on the nozzle should be obtained. The pressure head should be varied by 300 mm increments in order to determine (a) the maximum head at which no penetration occurs, (b) the change in penetration with increasing head and (c) the minimum head required to cause “breakdown” or the penetration of more than 5 g of water. At each pressure head a minimum of three specimens should be tested in order to obtain the average penetration for that head. | ||
| 9.1 Report the individual determinations. For values of over 5.0 g simply report as 5 + g or > 5 g. | 9 Report |
When laboratory managers, apparel engineers, or QA directors search for an ISO 22958 textiles – water resistance – rain tests protocol, They rarely type a single phrase into Google. Instead, They combine synonyms, product names, and use-case queries such as “ISO 22958 AATCC 35 fabric textile rain proof tester price,” “horizontal spray rain simulation chamber,” or “how to run AATCC TM35 water resistance: rain test step-by-step.” The modern rain tester from Wewon Environmental Chambers Co., Ltd. has been engineered precisely to intercept these long-tail keyword clusters.
Wewon’s rain test apparatus equipped with a programmable horizontal spray bar, calibrated nozzles, and a transparent acrylic cabinet, The instrument measures the penetration resistance of fabrics under ISO 22958 textiles test for water resistance to rain: horizontal spray method while also satisfying every clause of AATCC test method 35 water resistance: rain test. By consolidating dual-standard compliance into one benchtop footprint, the device eliminates the historical need for two separate machines, cutting capital expense, floor space, and operator training time.
In practice, Running the procedure is straightforward: mount a 200 mm × 200 mm conditioned specimen, Set the shower head to 27 ± 1 °C and 2.3 bar, initiate a 5-minute horizontal spray burst, and quantitatively weigh the blotting paper behind the fabric. A gain of less than 1.0 g typically certifies the material as “rain proof,” a phrase increasingly used in consumer-facing labels. The same chamber can be upgraded with an optional wind module to reproduce AATCC TM35 Annex A conditions,
Where horizontal airflow up to 18 km/h drives water droplets against the surface at oblique angles—critical for high-alpine jackets and motorcycle suits. Because the firmware stores unlimited test profiles, one click switches from ISO 22958 textiles – water resistance – rain tests: exposure to a horizontal water spray to the more stringent AATCC TM35 water resistance: rain test parameters, ensuring global brands can validate both European and North American retail requirements without retooling.
