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CAN CGSB 4.2 No. 5.1-M90 (2013): Breaking Strength of Textile Fabrics – Strip Method
A comprehensive guide to the Canadian standard for determining the breaking force and elongation of textile fabrics using the strip test method
Scope and Application
CAN CGSB 4.2 No. 5.1-M90 (2013) is a national standard of Canada developed by the Canadian General Standards Board (CGSB). It specifies a method for determining the breaking strength (force) and elongation of textile fabrics using the strip test procedure. The test is applicable to woven fabrics, nonwovens, felt, and similar textile structures, provided the fabric can be cut into strips of uniform width without significant fraying.
This standard is part of the CGSB 4.2 series of textile test methods and is equivalent in principle to ASTM D5035-11 (Strip Method). It is widely referenced in Canadian government procurement specifications and quality assurance programmes for textiles. The method is suitable for acceptance testing of commercial shipments and for internal quality control.
Tip: Although the standard was reaffirmed in 2013 with no technical changes, laboratories should verify that the referenced equipment calibration procedures are up to date with current metrological practices.
Technical Requirements and Testing Procedure
Test Principle
A strip of fabric of specified dimensions, raveled to a standard width (typically 50 mm), is clamped between two jaws of a testing machine. The jaw grips are moved apart at a constant rate of extension (CRE) or constant rate of traverse (CRT), whichever is specified, until the specimen ruptures. The maximum force recorded and the elongation at break are reported.
Specimen Preparation
Specimens are cut at least 150 mm long, with a nominal width of 50 mm. For fabrics that fray, the strips may be slightly wider and then raveled to exactly 50 mm by removing edge yarns. A minimum of five specimens per direction (warp/fill or machine/cross) are tested.
| Parameter | Specification |
|---|---|
| Specimen width | 50 ± 0.5 mm (raveled width) |
| Gage length | 200 ± 1 mm |
| Rate of extension | 100 ± 10 mm/min (CRE) or 300 ± 10 mm/min (CRT) |
| Conditioning atmosphere | 23 °C ± 2 °C, 50 ± 5 % RH for >24 h |
| Number of specimens | At least 5 per direction |
Apparatus Requirements
The testing machine must be capable of recording force with an accuracy of ±1 % of the indicated value within the test range. Jaw faces must be smooth, flat, and sufficiently wide to clamp the full width of the specimen. The standard permits both CRE (constant-rate-of-extension) and CRT (constant-rate-of-traverse) machines, provided the rate of movement is as specified. However, CRE machines are preferred by most modern laboratories because they reduce inertia effects and improve reproducibility.
Warning: All jaw faces should be inspected regularly for wear or contamination. Uneven clamping can cause premature jaw breaks and invalid results.
Conditioning
Fabric specimens must be conditioned at standard temperature and humidity (23 °C ± 2 °C, 50 ± 5 % RH) for a minimum of 24 hours prior to testing. If the fabric is expected to exhibit significant hygroscopic effects, longer conditioning time may be needed. Testing should be performed promptly after conditioning to minimize moisture regain changes.
Calculation and Reporting
The breaking force for each specimen is recorded in newtons (N) or kilogram-force (kgf), and the elongation at break is expressed as a percentage of the initial gage length. The average, standard deviation, and coefficient of variation are calculated for each direction. The report must also include the fabric description, test direction, conditioning details, and any noted anomalies such as jaw breaks.
Good practice: When jaw breaks occur (the specimen breaks at or within 5 mm of the jaw), the result should be flagged. If more than 20% of the specimens exhibit jaw breaks, the test method may need to be modified (e.g., using padded jaws or a different gripping system).
Implementation and Compliance Considerations
Use in Regulatory and Contractual Contexts
CAN CGSB 4.2 No. 5.1-M90 is referenced by many Canadian government departments (e.g., Public Works and Government Services Canada) for textile product qualification. Manufacturers supplying fabrics for uniforms, tents, industrial filters, and upholstery may be required to certify that their products meet the breaking strength limits specified in the applicable procurement document. The standard is also adopted by some Canadian military and aerospace specifications.
Correlation with Other Standards
The strip method defined in this standard yields results that are generally comparable to those obtained using ASTM D5035 (same method) and ISO 13934-1 (strip test) when the same gage length and rate are used. However, differences in jaw design, pre-tension, and conditioning can cause slight bias. It is recommended to validate correlation when changing from one standard to another.
Quality Assurance and Document Control
Testing laboratories should maintain up-to-date copies of the standard (available from CGSB) and ensure that technicians are trained on the specific steps for raveling and mounting. The standard does not currently require statistical process control, but implementing control charts for breaking strength can help detect drift in machine performance or fabric quality.
Important: The 2013 reaffirmation did not change the technical content of the 1990 edition. However, users must cross-check with any newer amendments or corrigenda issued by CGSB. As of 2026, the standard remains active.
Environmental and Safety Precautions
Operators should be aware of pinch points in the tensile tester and avoid placing hands near the moving crosshead. Specimens that break under tension may snap back; use of protective shields is recommended. Fabric dust from frayed edges may be an irritant; appropriate ventilation or PPE should be provided.
Q: Is CAN CGSB 4.2 No. 5.1-M90 still current?
A: Yes, the standard was reaffirmed in 2013 and, as of 2026, remains the current version. Users are advised to check the CGSB website for any subsequent amendments or withdrawals.
A: Yes, the standard was reaffirmed in 2013 and, as of 2026, remains the current version. Users are advised to check the CGSB website for any subsequent amendments or withdrawals.
Q: Can this method be used for elastic fabrics or narrow fabrics?
A: The strip method is intended for woven and nonwoven fabrics with limited extensibility. For highly elastic fabrics or narrow fabrics (e.g., tape), alternative methods such as the grab test (CGSB 4.2 No. 5.2) are more appropriate.
A: The strip method is intended for woven and nonwoven fabrics with limited extensibility. For highly elastic fabrics or narrow fabrics (e.g., tape), alternative methods such as the grab test (CGSB 4.2 No. 5.2) are more appropriate.
Q: What is the difference between the strip method and the grab method?
A: The strip method uses a full-width raveled specimen (50 mm wide) to test the fabric’s intrinsic strength. The grab method tests a wider specimen with only the central width gripped, which better simulates seam loading. The choice depends on the end-use application and the specification required.
A: The strip method uses a full-width raveled specimen (50 mm wide) to test the fabric’s intrinsic strength. The grab method tests a wider specimen with only the central width gripped, which better simulates seam loading. The choice depends on the end-use application and the specification required.
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Article prepared in 2026. For the latest official version of CAN CGSB 4.2 No. 5.1-M90 (2013), contact the Canadian General Standards Board or access the CGSB online catalogue.