GB/T 38034-2019Footwear - Test methods for slide fasteners - Lateral strength (English PDF)

3.1 slide fastener

a connecting piece for fixing two pieces of flexible material; it is composed of inter-lockable teeth attached to the opposite edges of two tapes and a movable slider that spans the teeth; when the slider moves in one direction, the teeth (3.5) on the two tapes (3.2) can be meshed with each other

NOTE: When the slider (3.3) moves in the opposite direction, the teeth can be separated (see Figure 1).

teeth

4.1 Tensile testing machine.

4.1.1 Clamp: separation speed is (100+/-10) mm/min.

4.1.2 Device that records the maximum force during the test: the force

measurement range is to 2.0kN; the accuracy is greater than 2%; meets the requirements for level two in ISO 7500-1.

4.1.3 Two clamps:

- Nip width is (25.5+/-0.5) mm;

- Clamping surface: a flat surface with ripples or covered with rough paper;

- Do not apply local pressure on the clamping edge.

4.2 Use a positioning fixture to fix two clamps (4.1.3). Make the clamping edges

parallel and center aligned. The minimum size of the metal block is 200mmx30mmx10mm, with a shallow slot with a minimum length of 200mm and a width of less than 26 mm, but large enough to allow the clamps (4.1.3) to move freely.

4.3 For heavy slide fastener, use solvent-based polychloroprene adhesive to

help the clamp (4.1.3) to clamp the stringer.

5.1 At least 3 test positions are required. Each test position is at least 50 mm

away from the free end of the slide fastener.

5.2 If there are 3 slide fasteners, test the midpoint of each slide fastener.

5.3 If there is only 1 slide fastener, test 3 positions, at least 50 mm from both

ends of the slide fastener and the midpoint of the slide fastener. During the test, the free length of the slide fastener at each end of the clamping area is at least

50 mm. Therefore, the total length of the chain is at least 275 mm. Each test can separate a segment of teeth. For the teeth with a total length close to 275 mm, until after each test, the nearby test position can be precisely determined.

5.4 For each test point, mark a line with a length of (25+/-2) mm on each stringer: