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CAN CGSB 4.2 No. 9.1-M90 (2013): Breaking Strength of Fabrics – Strip Method
A Comprehensive Guide to the Canadian Standard for Strip Method Breaking Strength Testing of Textile Fabrics
CAN CGSB 4.2 No. 9.1-M90 (2013) is a Canadian standard developed by the Canadian General Standards Board (CGSB) that specifies a strip method for determining the breaking strength and elongation of textile fabrics. This test method is widely employed in quality control, material specification, and product development across the textile industry. The standard provides a reliable and repeatable procedure for evaluating the tensile properties of woven, nonwoven, and coated fabrics under controlled conditions.
Scope
The scope of CAN CGSB 4.2 No. 9.1-M90 (2013) covers the determination of the maximum force (breaking strength) and the elongation at maximum force of textile fabrics using a strip test. It applies to fabrics of any fiber composition, construction, or finish, including woven, nonwoven, and certain coated textiles. The method is particularly suited for fabrics with a width suitable for cutting 50 mm wide strips. It is applicable to both conditioned and wet specimens.
This standard is intended for use by manufacturers, testing laboratories, regulatory bodies, and researchers who need to assess the tensile performance of textiles. It is referenced in various Canadian and international product specifications.
Important: The strip method described in this standard may not be appropriate for highly elastic fabrics (e.g., knits, stretch wovens) where the grab test or other methods are more suitable. Always verify the applicability before testing.
Technical Requirements
Specimen Preparation
Specimens shall be cut to a width of 50 mm ± 0.5 mm and a length sufficient to allow for the gripping distance (typically at least 200 mm). The edges must be parallel and free from ravelling. For woven fabrics, separate sets of specimens are prepared in the warp (lengthwise) and weft (crosswise) directions. A minimum of five specimens per direction is required.
Conditioning and Atmosphere
All specimens must be conditioned in a standard atmosphere of 20 ± 2°C and 65 ± 4% relative humidity for at least 24 hours prior to testing. Wet testing, if specified, requires immersion in distilled or deionized water with a wetting agent for a defined period.
Test Procedure
The test is performed on a constant rate of extension (CRE) tensile testing machine. The initial distance between grips (gauge length) is set to 75 mm. The rate of extension is 300 mm/min ± 10 mm/min. Each specimen is mounted with even tension, avoiding jaw breaks. The machine records the maximum force and the corresponding elongation.
Calculation and Expression of Results
Breaking strength is reported as the arithmetic mean of the maximum force values in newtons (N) for each direction. Elongation is reported as a percentage of the original gauge length. Standard deviation and coefficient of variation may also be calculated.
| Parameter | Requirement |
|---|---|
| Specimen width | 50 mm ± 0.5 mm |
| Gauge length (initial grip separation) | 75 mm ± 1 mm |
| Rate of extension | 300 mm/min ± 10 mm/min |
| Minimum number of specimens (per direction) | 5 |
| Conditioning atmosphere | 20 ± 2°C, 65 ± 4% RH |
| Conditioning time | ≥ 24 hours |
Tip: To avoid jaw breaks (specimen breaking at or near the grip), use appropriate jaw faces (e.g., rubberized or flat-faced) and ensure the specimen is aligned perpendicular to the grips.
Implementation Highlights
Equipment and Calibration
A constant rate of extension (CRE) tensile testing machine with a force measurement accuracy of ±1% of the applied load is required. The machine must be capable of maintaining the specified extension rate. Regular calibration using certified weights or a load cell is essential to maintain compliance.
Data Interpretation
Results are used for material specification, quality grading, and design input. Comparisons between fabrics should only be made when tests are performed under identical conditions and on similar material types. The elongation data helps evaluate fabric stretch characteristics and can indicate potential performance in end-use applications.
Common Pitfalls
- Incorrect grip pressure causing slippage or damage.
- Insufficient number of specimens leading to high variability.
- Non‑standard conditioning, especially in humid environments.
Good Practice: Regularly monitor the testing environment with a calibrated hygrometer/thermometer and record conditions for each test series to ensure reproducibility.
Compliance Notes
Reporting
A test report according to CAN CGSB 4.2 No. 9.1-M90 (2013) must include:
- Reference to this standard (CAN CGSB 4.2 No. 9.1-M90 (2013)).
- Fabric description, sampling method, and conditioning details.
- Number of specimens tested and direction (warp/weft).
- Breaking strength (mean, standard deviation) in newtons.
- Elongation at maximum force (mean, standard deviation) in percent.
- Any deviations from the standard procedure.
Acceptance Criteria
The standard does not prescribe pass/fail values; these are specified in product standards, contracts, or internal quality plans. However, a coefficient of variation exceeding 10% may indicate inadequate test control or material non‑uniformity.
Limitations and Considerations
The strip method tests a narrow width of fabric; results may not reflect the behaviour of the fabric in use under multiaxial stresses. Fabrics with fringed edges or low stability may require pre‑ravelling allowance or alternative methods.
Caution: This standard was reaffirmed in 2013. Always verify with the latest version from CGSB or an official standards body to ensure current compliance.
Frequently Asked Questions
Q: What is the difference between the strip method (CGSB 4.2 No. 9.1) and the grab test?
A: The strip method tests the entire width of a narrow specimen (50 mm) with both selvedges removed, whereas the grab test clamps only the centre of a wider specimen. The strip method generally yields lower strength values because it tests the full fabric structure in a more constrained manner. The grab test is more representative of seam strength in some applications.
A: The strip method tests the entire width of a narrow specimen (50 mm) with both selvedges removed, whereas the grab test clamps only the centre of a wider specimen. The strip method generally yields lower strength values because it tests the full fabric structure in a more constrained manner. The grab test is more representative of seam strength in some applications.
Q: Can this standard be used for coated or laminated fabrics?
A: Yes, provided the specimen can be cut to the required width without delamination or damage. For highly stretchable or delicate coatings, the grip pressure and jaw faces may need adjustment; the standard allows such modifications but they must be reported.
A: Yes, provided the specimen can be cut to the required width without delamination or damage. For highly stretchable or delicate coatings, the grip pressure and jaw faces may need adjustment; the standard allows such modifications but they must be reported.
Q: How do I convert breaking strength values to other units?
A: The standard reports force in newtons (N). To convert to kilograms-force (kgf), divide by 9.80665. For pounds-force (lbf), multiply by 0.224809. Always include the conversion factor in any documentation.
A: The standard reports force in newtons (N). To convert to kilograms-force (kgf), divide by 9.80665. For pounds-force (lbf), multiply by 0.224809. Always include the conversion factor in any documentation.
Q: Is wet testing mandatory under this standard?
A: Wet testing is only required if specified in the material specification or contract. The standard provides instructions for wetting the specimens, but the default method is conditioned testing in a standard atmosphere.
A: Wet testing is only required if specified in the material specification or contract. The standard provides instructions for wetting the specimens, but the default method is conditioned testing in a standard atmosphere.
© 2026 International Standards Review. This article is for informational purposes and does not replace the official standard. Always consult the full text of CAN CGSB 4.2 No. 9.1-M90 (2013) for complete requirements.