NEN EN ISO 13937-4 : 2000

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Sampling
6 Apparatus
7 Atmosphere for conditioning and testing
8 Preparation of test specimens
9 Procedure
10 Calculation and expression of results
11 Test report
Annex A (informative) Suggested procedure for sampling
Annex B (informative) Example of pattern for cutting out
                      test specimens from the laboratory
                      sample
Annex C (informative) Sample calculation of tear force
Bibliography

Describes a double-tear procedure known as the tongue test, with a test specimen with cuts that are shaped to form a tongue. The tear force measurement is the force needed 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 force. Applies mainly to woven textile fabrics but also covers fabrics produced by other techniques, such as some nonwovens. Does not generally apply to woven elastic fabrics and knitted fabrics.