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This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB/T 3903.43-2008 Footwear - Test methods for uppers, lining and insocks - Seam strength, and the following main technical changes have been made with respect to GB/T 3903.43-2008:
——The normative references are modified (see Clause 2, Clause 2 of Edition 2008);
——Requirements on the accuracy of the force value measured by the tensile testing machine are added (see 4.1.1 and 4.2.1);
——The force range adapted to the test specimen is modified (see 4.2.1; 4.2.1 of Edition 2008).
This part, by means of translation, is identical to ISO 17697: 2016 Footwear - Test methods for uppers, lining and insocks - Seam strength.
The Chinese documents identical to the normative international documents given in this part are as follows:
——GB/T 16825.1-2008 Verification of static uniaxial testing machines - Part 1: Tension/compression testing machines - Verification and calibration of the force-measuring system (ISO 7500-1: 2004, IDT)
——GB/T 22049-2019 Footwear - Standard atmospheres for conditioning and testing of footwear and components for footwear (ISO 18454: 2018, IDT)
——GB/T 22050-2008 Footwear - Sampling location, preparation and duration of conditioning of samples and test pieces (ISO 17709: 2004, IDT)
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This part was proposed by China National Light Industry Council.
This part is under the jurisdiction of SAC/TC 305 National Technical Committee on Footwear of Standardization Administration of China.
The previous edition of the standard replaced by this part is as follow:
——GB/T 3903.43-2008.
Footwear - Test methods for uppers, lining and insocks - Seam strength
1 Scope
This part of GB/T 3903 specifies two test methods for determining the seam strength of uppers, lining or insocks, in order to assess the suitability for the end use.
This part is applicable to uppers, lining or insocks of various materials.
These methods are as follows:
——Method A: Needle perforations. For determining the force required to pull a row of needles through an upper material, in a direction perpendicular to the row.
——Method B: Stitched seams. For determining the breaking strength of stitched seams in shoe upper and lining materials. This method is applicable to seams cut from shoes or made up to simulate footwear constructions.
2 Normative references
The following referenced documents are indispensable for the application 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.
ISO 7500-1 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 17709 Footwear - Sampling location, preparation and duration of conditioning of samples and test pieces
ISO 18454 Footwear - Standard atmospheres for conditioning and testing of footwear and components for footwear
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
seam strength
breaking strength of a stitched seam as determined under specified conditions using a tensile testing machine
3.2
upper
materials forming the outer face of the footwear which is attached to the sole assembly and covers the upper dorsal surface of the foot
Note: In the case of boots, this also includes the outer face of the material covering the leg. Only the materials that are visible are included, no account should be made of underlying materials.
3.3
complete upper assembly
finished upper, fully seamed, joined or laminated as appropriate, comprising the center material and any lining(s) together with all components such as interlinings, adhesives, membranes, foams or reinforcements, but excluding toe puffs and stiffeners
Note: The complete upper assembly can be flat, 2-dimensional or comprise lasted upper in the final footwear.
4 Apparatus and material
The following apparatus and material shall be used.
4.1 Method A
4.1.1 Tensile testing machine, with a jaw separation rate of (100 ± 10) mm/min, a force range appropriate to the specimen under test (this will usually be less than 500 N for footwear upper materials), capable of measuring forces to an accuracy greater than 2 % as specified by Class 2 in ISO 7500-1.
4.1.2 Needle holding jig, see Figure 1, including the following:
4.1.2.1 Two rectangular rigid plates, each of minimum width 30 mm and maximum thickness 6 mm. Each of the two plates is drilled with 17 holes of diameter (1.1 ± 0.1) mm. The holes shall be in a straight line parallel to and approximately 5 mm from one end of the plate. The holes should be evenly spaced so that the centers of the two extreme holes are (26.5 ± 0.5) mm apart.
4.1.2.2 One spacing plate, of width similar to the drilled plates and of thickness (3.5 ± 0.5) mm.
4.1.2.3 Means of securing the spacing plate, to the surface of one of the drilled plates such that the distance between the end of the spacing plate and the center line of the row of holes in the other plate can be adjusted and set at (3.0 ± 0.1) mm and (6.0 ± 0.2) mm. The combination will be referred to as the lower plate.
4.1.2.4 Means of securing the other drilled plate, which will be referred to as the upper plate, to the exposed surface of the spacing plate so that the holes in both of the drilled plates are aligned.
The end of one of the plates furthest from the row of holes should have means of attachment to one of the jaws of the tensile testing machine so that the rows of holes are perpendicular to the axis of the machine.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Apparatus and material
5 Sampling and conditioning
6 Test methods
7 Test results
8 Test report
Bibliography
