It is concluded that the breaking (tearing) of fabric is a common and easy to happen damage form. Because of the particularity of the local force at the crack, the tearing strength of the fabric is much less than the tensile fracture strength. The fracture strength index is the main quality index to measure the damage resistance of fabric under local force in the process of use. In order to improve the life of fabric, it is necessary to study the tearing of fabric in order to improve the life of fabric. So today, the science of measurement and control Xiaobian will introduce a method of detecting the performance of textile fabrics in detail.

Methods for testing the properties of textiles (strip sample method)

I. Test scope and strip test:

1, Scope: This part is mainly applicable to woven fabrics, also applicable to fabrics produced by other technologies, usually not used for elastic fabrics, geotextiles, glass fiber fabrics and carbon fiber and polyolefin flat silk fabrics.

2. The whole width of the sample is a fabric tensile test held by the gripper

Two, the principle of sample

The fabric sample of specified size is stretched at a constant elongation rate until it breaks off. Record breaking strength and elongation at break, if necessary.

Iii. Sampling

1, sample standard:

Two sets of samples are clipped from each laboratory sample, one for the meridional (or longitudinal) and the other for the zonal (or transverse). Each set of samples shall consist of at least 5 samples, and if higher accuracy is required, the number of samples shall be increased. The sample should be at least 150 mm away from the cloth edge. The meridional (or longitudinal) test sets should not be sampled at the same length, and the zonal (or transverse) test sets should not be sampled at the same length.

2, sample size:

The effective width of each specimen shall be 50 mm0,5 mm(excluding the raw edge). The length shall be sufficient for the interval length of 200 mm. If the specimen has more than 75% elongation at break, the interval length may be 100 mm. Other widths may be used as agreed by the parties concerned and shall be stated in the test report.

Four, breaking strength and elongation at break

1. maximum force of breaking strength

The maximum force recorded when the specimen is broken during the tensile test under specified conditions (see Figure 1)

2, elongation at break elongation at maximum force under the action of the sample (see Figure 1)

Explanation:

1. Breaking strength:

2, breaking strength;

3. Pre-tension:

4. Elongation at break;

5. Elongation at break

6. Elongation

5. Test equipment

1, the characteristics of the test instrument:

The measurement confirmation system of constant velocity extension (CRE) tester shall comply with the provisions of GB/T 19022. The constant elongation (CRE) tester shall have the following general characteristics:

a) A device shall be provided to indicate or record the force applied to the specimen to stretch it until it breaks and the corresponding specimen elongation. The accuracy of the instrument shall meet the requirements of Class 1 specified in GB/T 16825.1. At any point in the full range of the device, the error indicating or recording the breaking force shall not exceed 1%, and the error indicating or recording the clamp spacing shall not exceed 1 mm. If the tensile tester of GB/T 168251 with grade 2 accuracy is used, it shall be stated in the test report.

b) If data acquisition circuits and software are used to obtain force and elongation values, the frequency of data acquisition shall not be less than 8 times /s.

c) The instrument shall be able to set the drawing speed of 20 mm/min and 100 mm/min with an accuracy of 10%.

d) The instrument shall be able to set the distance length accuracy of 100 mm and 200 mm to 1mm.

e) The center point of the two clamps of the instrument should be on the tension axis, the jaws of the clamp should be perpendicular to the tension line, and the clamping surface should be on the same plane. The clamp face should be able to hold the sample without making it slip, shear or damage the sample. The clamp face should be flat and smooth. When the sample cannot be prevented from sliding by the flat clamp, grooves with grooves can be used. Other auxiliary materials (including paper, leather, plastic and rubber) can be attached to the flat or textured clamp surface to improve the gripping force of the sample. The width of the clamp face shall be at least 60 mm, and shall not be less than the width of the sample.

Note, if the use of a flat clamp does not prevent slipping of the specimen or cracking of the clamp, the elongation can be measured by using a winch clamp and tracking two marked points on the specimen with an elongation meter.

2. Test equipment

a) Equipment for cutting samples and removing yarn.

b) Apparatus for wetting samples in water.

c) Tertiary water in accordance with the requirements of GB/T6682 is used to wet the sample

d) 6.5 Non-ionic wetting agent.

Vi. Measurement and recording

Hold the sample at the center of the clamp to ensure that the center line of tension passes through the midpoint of the clamp.

Start the tester, make the movable gripper move, and stretch the sample to break off. The breaking strength was recorded in Newtons (N). Record the elongation at break or elongation at break in millimeters (mm) or percentage (%). Record breaking strength, breaking elongation, and breaking elongation if necessary.

Record elongation at break or elongation at break to the nearest value:

{1}- Elongation at break <8% :0.4mm or 0.2%;

{2}- elongation at break >8% and ≤75%lmm or 0.5%;

{3} elongation at break >75% :2mm or 1%.

{4} Test at least 5 specimens in each direction.

The above is the introduction of the test method of textile fabric performance. I hope it can help you. If you also want to know more about the tensile testing machine on the quality of textile fabric performance inspection, testing instrument operation, testing items and testing new methods. Then, you are welcome to pay attention to us, the department of measurement and control team for your free answer!