QB/T 4331-2021Children athletic shoes (English PDF)

4.1 By upper material

5.3.2 Folding resistance of finished shoes

5.3.2.1 Folding resistance of finished shoes shall not be measured, if any of the following conditions occur:

a) The shoe size is less than 230;

b) The thickness of the flexion part of the sole (including the pattern) is greater than

25 mm.

Note: The thickness of the flexion part of the sole includes the thickness of the insole, but does not include the thickness of the bottom wall part higher than the insole.

5.3.2.2 The requirements for the folding resistance of finished shoes are shown in Table

2.

5.3.3 Outsole wear resistance

5.3.3.1 Infants’ athletic shoes are not tested for wear resistance.

5.3.3.2 The length of the wear mark shall not be greater than 14.0 mm.

5.3.4 Low-temperature flexural performance of the upper surface material

5.3.4.1 Infant’s athletic shoes are not tested for low-temperature flexural performance of the upper surface material.

5.3.4.2 The low-temperature flexural performance of the upper material of shoes worn

in nominal low-temperature environments (such as winter or warm shoes, etc.) shall comply with the requirements of QB/T 2224.

5.3.5 Friction color fastness of lining and insole

The staining shall not be less than level 2-3; the gray scale shall comply with the provisions of GB/T 251.

5.3.6 Outsole hardness

5.3.6.1 The outsole hardness of infant’s athletic shoes is not measured.

5.3.6.2 The outsole hardness of solid material shall not be less than 40 Shore A; the

It is tested according to GB/T 3903.2; the wear time is 20 minutes continuously. When testing the wear resistance of the foam material outsole, the surface dense layer is not polished. If the flat area does not meet the test requirements, this item is not performed.

7.5 Low temperature flexing performance of upper material

It is tested according to the provisions of QB/T 2224. If sampling is not possible, materials from the same batch can be tested.

7.6 Friction color fastness of lining and insole

7.6.1 Take lining and insole materials as specimens. If there is no lining, the contact surface between the upper and the foot is tested as the lining. If sampling is not possible, materials from the same batch can be tested.

7.6.2 It is tested according to method A in QB/T 2882-2007, to carry out 50 wet rubs for testing. The test results are evaluated according to the gray scale of GB/T 251 for staining grade.

7.7 Outsole hardness

It is tested according to the provisions of GB/T 3903.4. When testing the hardness of the outsole of the foam material, do not polish the surface dense layer; the outsole can be tested at any part of the forefoot or heel if it is a single material; the composite sole is tested at the stress point; the patch material shall be tested together with the whole shoe. Different materials at the stress point shall be tested separately and the results expressed.

7.8 Adhesion strength of outsole and outer midsole

It is tested according to the provisions of GB/T 21396; the test result is the lower value of the test result.

7.9 Anti-fatigue performance of hook and loop tape

7.9.1 Test the peel strength before and after repeated opening and closing of the same batch of materials, according to the provisions of GB/T 3903.20.

7.9.2 According to the provisions of GB/T 3903.21, take the same batch of materials to test the shear strength before and after repeated opening and closing.

8.1 If the main items of labeling, physical, mechanical properties and sensory quality

meet the requirements of this document, meanwhile no more than 2 items of sensory quality minor items do not meet the requirements of this document, the product shall be judged as qualified.

Appendix A (Informative)

After-sales quality judgment of children’s athletic shoes

A.1 After-sales service period

It can be determined by the manufacturer according to the product grade, which shall be clearly stated in the after-sales service provisions.

A.2 After-sales quality judgment

In the case of normal wear within the after-sales service period, the following problems can be judged as quality problems:

a) Failing to meet the quality requirements of qualified products in the product standard;

b) Protruding nail tips (heads) inside the shoe, uneven inside the shoe affects wearing;

c) Upper cracks, broken or cracked uppers, severe white frost, discoloration; natural leather uppers are obviously loose, the coating layer falls off or cracks;

d) Open thread, open glue;

e) The main heel or toe box is deformed;

f) The lining or inner pad is obviously discolored and contaminates the socks; the lining is worn;

g) The outer sole or inner sole is cracked, broken or uneven, affecting wearing;

h) The surrounding strip is open and broken;

i) The air (liquid) cushion has leakage (liquid) and collapse;

j) Other defects that affect wearing.

A.3 Inspection method

A.3.1 Sensory quality shall be inspected in accordance with the provisions of GB/T

3903.5.

A.3.2 Decolorization: Use white absorbent cotton or gauze soaked with clean water (no

water dripping when pressed with fingers) to gently press the inner side of the upper (lining) or inner pad within 10 cm; rub back and forth 10 times; observe the absorbent cotton or gauze; if there is obvious contamination, it is judged as unqualified.

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