Tensile Strength of Textile Fabrics
2024-10-15

Determination of Breaking Strength, and Elongation at Break of Textile Fabrics

(Strip Method)



Reference Standards
- ISO 139: Textiles — Standard Atmospheres for Conditioning and Testing
- IKEA Specification: ISO-TM-0007

Principle
A sample of specified dimensions is subjected to a constant rate of extension until it breaks. The breaking strength and elongation at break are recorded.

Equipment
- Testing Device: YG(B)026H-250 Electronic Fabric Strength Tester
- Sensor: 2500N
- Clamps: 200cN, 500cN, 1000cN
- Tools: Scissors

Procedure
1. Before testing, condition the sample according to ISO 139, maintaining a temperature of 20±2℃ and a humidity of 65±4% for at least 24 hours.
2. Select representative samples, avoiding areas with folds, creases, or fabric edges. Take 6 samples in each direction (warp and weft). The first sample is used for pre-testing and is not included in the final results.
3. Since the clamps are made of rubber, the sample may slip during stretching. Therefore, it is recommended to cut the sample to 60x350mm and then trim the edges to 50x300mm. If the yarn is difficult to trim (e.g., if coated or laminated), directly prepare the sample to 50x300mm.
4. Set the gauge length and extension speed of the strength tester and select the appropriate pre-tension clamp. Initially, perform a pre-test with a gauge length of 200mm and an extension speed of 100mm/min, then adjust these parameters according to the elongation range specified in Table 1 for the official test.

Table 1: Extension Speed and Gauge Length

  Breaking elongation rate of fabric (%)    < 8    8 ≤ & < 75    > 75  
Gage length (mm)200200100
Stretching speed (mm/min)20100100


Choose the appropriate pre-tension clamp according to the mass per unit area of the sample.

Table 2: Pre-Tension Clamp Selection

  Fabric weight (g/m²)    Gripprt tension (cN)  
≥ 200200
200 < & ≤ 500500
> 500
1,000


Fix the sample at the center of the clamp, start the strength tester, and extend the sample until it breaks. Record the breaking strength (in N) and the elongation at break (in % and mm).

5. If the sample breaks within 5mm of the clamp, it is considered a clamp break. If the clamp break value is greater than the minimum value of other test results, retain it; otherwise, discard it and test a new sample to ensure five valid breaking strength values are obtained.

6. After the test, calculate the average breaking strength (N) and elongation at break (%) for both warp and weft directions. The results should be rounded as follows:
   - Breaking strength: Round to 1N if <100N; to 10N if between 100N and <1000N; to 100N if ≥1000N.
   - Elongation at break: Round to 0.2% if <8%; to 0.5% if between 8% and ≤75%; to 1% if >75%.

Test Report
The report should include the reference standard and its version, a description of the sample, the date of receipt, the test date, the values of breaking strength, and elongation at break.