GB/T 3917.3-2025 Textiles - Tear properties of fabrics - Part 3: Determination of tear force of trapezoid-shaped test specimens
1 Scope
This document describes a method for determination of tear force by rapezoid-shaped test specimens.
This document applies to woven fabrics (except woven elastic fabrics) and nonwoven fabrics.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 6529 Textiles - Standard Atmospheres for Conditioning and Testing (GB/T 6529-2008, ISO 139: 2005, MOD)
GB/T 6682 Water for analytical laboratory use - Specification and test methods (GB/T 6682-2008, ISO 3696: 1987, MOD)
GB/T 16825.1-2022 Metallic materials - Calibration and verification of static uniaxial testing machines - Part 1: Tension/compression testing machines - Calibration and verification of the force-measuring system (ISO 7500-1: 2018, IDT)
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 document, the following term and definition apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
constant rate of extension testing machine; CRE testing machine
tensile-testing machine where one clamp is stationary whilst the other is moving with a constant speed throughout the test
3.2
constant rate of traverse testing machine; CRT testing machine
test apparatus in which one transverse gripper moves at constant rate and the other gripper driving the weight mechanism applies a load
Note: The growth rate of load or elongation of the specimen in the test depends on the elongation characteristics of the specimen.
3.3
gauge length
distance between the two effective clamping points of a testing device
Note: The effective clamping points (or lines) of jaws can be checked by clamping a test specimen under defined pretension with carbon copy paper to produce a gripping pattern on the test specimen.
3.4
tear force
force required to propagate a tear initiated under the specified conditions
Note 1: For woven fabrics, the force at which the warp yarn is torn is called "warp tear force" and the force at which the weft yarn is torn is called "weft tear force".
Note 2: For nonwovens, the force to be torn in the transverse direction is the "transverse tear force" and the force to be torn in the longitudinal direction is the "longitudinal tear force".
3.5
peak
corresponding force value at the point where the slope changes from positive to negative on the force-elongation curve
Note: The ascending force and descending force values at both ends of the peak used for calculation are at least 10% of the descending value of the previous peak or the appreciation increase of the subsequent peak.
3.6
trapezoid-shaped test specimen
Rectangular fabric tear test specimen..
Note: The specimen is marked with two marking lines of specified size and forming an isosceles trapezoid holding the specimen. The center of the short side of the trapezoid is cut with a cut of specified size.
4 Principle
Marking of a trapezoid on a test specimen. Cutting of a specified cut in the center of the short side of the trapezoid. Clamping of the non-parallel sides of the trapezoid in the jaws of a tensile testing machine. Application of a continuously increasing extension to the test specimen in such a way that a tear propagates across its width. The force to continue the tear over a specified distance is recorded. The arithmetic mean of the maximum force of specimens is taken as the result of testing. Take the arithmetic mean of the effective peak mean of all samples in one direction for woven fabrics as the test result, and take the arithmetic mean of all samples in one direction for non-woven fabrics as the test result. The unit is Newton (N).
5 Apparatus and materials
Contents
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Apparatus and materials
6 Sampling
7 Preparation and wet conditioning of test specimens
8 Procedure
9 Calculation and expression of results
10 Test report
