Understanding CAN/CGSB-4.2 No. 27.4-2010: Static Immersion Water Absorption Test for Textiles

1. Scope and Purpose

CAN/CGSB-4.2 No. 27.4-2010, part of the larger CAN/CGSB-4.2 suite of textile test methods, establishes a standard procedure for determining the water absorption of textile fabrics by static immersion. This method is applicable to woven, knitted, and nonwoven textile fabrics, including those that are chemically finished or coated. It measures the amount of water absorbed by a fabric specimen when fully immersed in distilled water under controlled conditions, expressed as a percentage of the dry mass.

The standard serves industries where fabric water absorbency is critical, such as apparel (e.g., towels, sportswear), medical textiles, filtration media, and household linens. Unlike dynamic tests (e.g., spray or hydrostatic head), the static immersion test assesses the intrinsic absorbency of the fabric structure and fibers without external pressure, making it ideal for quality control and comparative end-use evaluation.

The 2010 edition reaffirms previous technical requirements and adjusts conditioning and reporting provisions to align with contemporary laboratory practices.

2. Technical Requirements

2.1 Apparatus and Materials

The standard specifies the following equipment:

• Balance with accuracy of 0.01 g for weighing specimens
• Container (glass, stainless steel, or plastic) large enough to allow free movement of water around the specimen
• Distilled or deionized water at 23 °C ± 2 °C
• Blotting material (filter paper or absorbent cloth) with a defined absorbency
• Conditioning room or chamber maintained at 20 °C ± 2 °C and 65 % ± 4 % relative humidity
• Timer or stopwatch

2.2 Specimen Preparation

Five 100 mm × 100 mm specimens are cut from the fabric, avoiding areas within 100 mm of the selvedge. Each specimen is conditioned for at least 4 hours under standard atmospheric conditions (20 °C ± 2 °C, 65 % ± 4 % RH). For fabrics that are sensitive to humidity, conditioning time may be extended until mass constancy is achieved (change ≤ 0.25 % over 2 hours).

2.3 Test Procedure

1. Weigh each conditioned specimen to the nearest 0.01 g (initial mass, m₀).
2. Immerse the specimen fully in distilled water at 23 °C ± 2 °C for 1 hour ± 1 minute.
3. Remove the specimen, drain for 10 seconds, then place between two layers of blotting material and roll with a 2.27 kg roller (turned three times) to remove excess surface water.
4. Weigh the wetted specimen immediately (final mass, m₁).

The water absorption (%) is calculated per specimen as:

Absorption (%) = (m₁ – m₀) / m₀ × 100%

Report the mean of five specimens, rounded to the nearest 0.1%.

2.4 Performance Criteria

The standard does not prescribe pass/fail limits. However, Table 1 provides typical absorption ranges for common textile end-uses.

Note: Values are illustrative; actual limits should be agreed upon between buyer and seller.

3. Implementation Highlights

3.1 Conditioning Consistency

Proper conditioning is critical for reproducible results. Fabrics with finish chemicals (e.g., hydrophilic or silicone coatings) may require 24-hour conditioning to achieve mass equilibrium. Laboratories should monitor humidity chamber logs and verify with calibrated hygrometers. The standard allows alternative conditioning times if stated in the report.

3.2 Blotting Technique

The blotting step is the most operator‑sensitive part. The standard requires a 2.27 kg roller (similar to that used in ASTM D2402) and specifies its turning direction. Operators should practice a consistent rolling speed (approximately 1 revolution per second) to minimize variability. Automated roller devices can improve inter‑laboratory repeatability.

3.3 Water Quality

Distilled or deionized water is mandatory because minerals or additives in tap water alter surface tension and affect absorbency. Change the water after each set of specimens or when temperature drifts outside ±2 °C of 23 °C. To avoid cross‑contamination, rinse the immersion container with distilled water between tests.

4. Compliance Notes

4.1 Certification and Accreditation

Manufacturers seeking to claim compliance with CAN/CGSB-4.2 No. 27.4-2010 should have their test methods accredited by the Standards Council of Canada (SCC) or an ISO/IEC 17025 accredited laboratory. Third-party certification helps ensure that test results are accepted across the supply chain.

4.2 Reporting Requirements

Each test report must include:

• Reference to the standard (CAN/CGSB-4.2 No. 27.4-2010)
• Number of specimens tested (minimum five)
• Indication of conditioning time if different from 4 hours
• Mean absorption percentage and coefficient of variation
• Any deviations from the standard procedure

4.3 Inter-laboratory Comparisons

Proficiency testing programs (e.g., those organized by ASTM or AATCC) can help labs benchmark their results. For fabrics with high variability, consider increasing the sample size from 5 to 10 specimens to improve statistical confidence. The standard does not prohibit larger sample sizes as long as they are documented.

Frequently Asked Questions

Article prepared for technical reference. The current edition of this standard is CAN/CGSB-4.2 No. 27.4-2010. Copyright © 2026 Canadian General Standards Board. All rights reserved.