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  • ISO 13937 Tear Force Test of Trouser, Wing and Tongue Shaped Fabric Specimens

ISO 13937 Tear Force Test of Trouser, Wing and Tongue Shaped Fabric Specimens

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ISO 13937-1 Ballistic Pendulum Method Tear Force of Textiles

ISO 13937-1 describes a method known as the ballistic pendulum (Elmendorf) method for the determination of tear force of textile fabrics. The method describes the measurement of the tear force required to propagate a single-rip tear of defined length from a cut in a fabric when a sudden force is applied. The test is mainly applicable to woven textile fabrics. It may be applicable to fabrics produced by other techniques, e.g. to nonwovens (with the same under-mentioned restrictions as for the woven fabrics). In general the test is not applicable to knitted fabrics and woven elastic fabrics. It is not suitable for highly anisotropic fabrics or loose fabrics where tear transfer from one direction to another direction of the fabric during the tear test is likely to occur.

Equipment Required 

Pendulum testing mahcine, in which the test specimen is held between two jaws, one movable and the other fixed to the frame. The moving jaw is attached to a pendulum which can fall under the influence of gravity. The pendulum shall provide for the test specimen to be torn without coming in contact with the pendulum during the test.

ISO 13937-2 Tear Force of Trouser-Shaped Test Specimens (Single Tear Method)

ISO 13937-2 describes a single-tear method to determine fabric tear force, known as the trouser test, using a test specimen cut to form trouser-shaped legs. The tear force measured is the force required to propagate a previously started single tear when the force is applied parallel to the cut and the fabric tears in the direction of applied force. The test is mainly applicable to woven textile fabrics. It may be applicable to fabrics produced by other techniques, e.g. to some nonwovens (with the same under-mentioned restrictions as for the woven fabrics). In general the method is not applicable to knitted fabrics and woven elastic fabrics. It is not suitable for highly anisotropic fabrics or loose fabrics where tear transfer from one direction to another direction of the fabric during the tear test is likely to occur. The method only allows the use of constant-rate-of-extension (CRE) testing machines.

Equipment Required

The tensile-testing machine(CRE), which shall be provided with means for indicating or recording the force applied to the test specimen in extending it. Under conditions of use, the accuracy of the apparatus shall be either class 1 or class 2 of ISO 7500-1. The error of the indicated or recorded maximum force at any point in the range in which the machine is used shall not exceed +- 1 %. The machine shall be capable of constant rate of extension of (100 +- 10) mm/min. The machine shall be capable of setting the gauge length to (100 +- 1) mm.

ISO 13937-3 Textiles Tear Wing-Shaped Test Specimens

ISO 13937-3 describes a single tear method to determine fabric tear force, known as the wing test using a test specimen cut to form two wings for clamping inclined at a defined angle to the thread direction. The tear force measured is the force required to propagate a previously started tear. The test is mainly applicable to woven textile fabrics. It may be applicable to fabrics produced by other techniques. Due to the clamping of the specimen wings inclined to the threads to be torn the test can be used for most types of fabrics without causing a transfer of tear and it is less susceptible to withdrawal of threads than other tear tests. In general the method is not applicable to knitted fabrics, woven elastic fabrics and nonwovens, to which the trapezoidal test method is preferably applied (Note 2). The method only allows the use of constant-rate-of-extension (CRE) testing machines.

Equipment Required

The tensile-testing machine(CRE), which shall be provided with means for indicating or recording the force applied to the test specimen in extending it. Under conditions of use, the accuracy of the apparatus shall be either class 1 or class 2 of ISO 7500-1. The error of the indicated or recorded maximum force at any point in the range in which the machine is used shall not exceed +- 1 %. The machine shall be capable of constant rate of extension of (100 +- 10) mm/min. The machine shall be capable of setting the gauge length to (100 +- 1) mm.

ISO 13937-4 Textile Tear properties of Tongue-Shaped Fabric Test Specimens (Double Tear Test)

ISO 13937-4 describes a double-tear method known as the tongue test, using a test specimen with cuts shaped to form a tongue. The tear force measured is the force required to propagate the previously started double tears when the force is applied parallel to the cuts and the fabric tears in the direction of the applied force. The test is mainly applicable to woven textile fabrics. It may be applicable to fabrics produced by other techniques, e.g. to some nonwovens (with the same under-mentioned restrictions as for the woven fabrics). In general the method is not applicable to knitted fabrics and woven elastic fabrics. The method only allows the use of constant-rate-of-extension (CRE) testing machines.

Equipment Required

Constant-rate-of-extension machine having the following characteristics: capable of operating at a constant-rate-of-extension of (100 +- 10) mm/min; capable of gauge length to be set to 100 mm +- 1 mm; provided with a means for recording the force applied to the test specimen during the tear test; under conditions of use, the accuracy of the apparatus shall be class 1 of ISO 7500-1. The error of the indicated or recorded maximum force at any point in the range in which the machine is used shall not exceed +- 1 % and the error of the indicated or recorded jaw separation shall not exceed +- 1 mm; if recording of force and extension is obtained by means of data acquisition boards and software, the frequency of data collection shall be at least 8 per second.