1 Scope
This part of GB/T 3917 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.
2 Normative references
The following normative documents contain provisions through reference in this text; constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 6529 Textiles—Standard atmospheres for conditioning and testing (GB/T 6529 - 2008, ISO 139: 2005, MOD)
GB/T 19022 Measurement management systems-Requirements for measurement processes and measuring equipment (GB/T 19022-2003, ISO 10012: 2003, IDT)
3 Terms and definitions
For the purposes of this part of GB/T 3917 the following terms and definitions apply:
3.1 tear force
Force required to propagate a tear initiated under the specified conditions.
Note: The tear force is qualified as "across warp" or "across weft" according to whether the tear is made across the warp (warp threads are torn) or weft (weft threads are torn) respectively.
3.2 length of tear
Measured from the beginning of the tear to the termination point.
