1 Scope
This document describes test methods for the peeling of the upper from the outsole, separation between the composite layers of the sole, and tear damage to the upper or sole of a shoe. It also specifies the ageing conditions for production control.
This document applies to all footwear (adhesive, vulcanised, injection moulded, etc.) where the strength of the sole and upper bond is to be determined and where the shoe is a complete upper (closed shoe).
Note 1: In all cases, the bond strength is measured closest to the edge of the bonding area.
Note 2: Shoes assembled with nails (e.g. with staples or screws) or sewn together do not require testing.
2 Normative references
The contents of the following documents constitute essential provisions of this document by means of normative references in the text. Where a reference is dated, only the version corresponding to that date applies to this document; undated references apply to the latest version of the document (including all amendment sheets).
3 Terms and definitions
The following terms and definitions apply to this document.
3.1
upper-sole adhesion
The force required to peel off a unit width of the upper-sole interface.
4 Apparatus and materials
The following apparatus and materials should be used.
4.1 Cutting equipment
Sharp cutters for cutting specimens.
4.2 Tensile testing machine
The tensile strength tester shall meet the requirements of ISO 7500-1 for class 2 accuracy, with a tensile speed of 100 mm/min ± 10 mm/min and a test range of ОN to 600 N. The tensile strength tester shall be fitted with a clamp or flat fixture (depending on the type of construction of the specimen), 25 mm to 30 mm wide, capable of clamping the specimen.
The tensile strength tester should be low inertia and have an automatic tensile strength recording device.
4.3 Measuring equipment
Calibrated equipment for measuring the width of the glued edge of the upper with an accuracy of not less than 0.5 mm,
5 Sampling and adjustment
5.1 Adjustment of the shoe
Before dismantling the shoe and cutting the specimen, the shoe is conditioned in the standard environment according to ISO 18454 for at least 24 h. If required, ageing is carried out according to Appendix A.
Note that some adhesives do not reach their maximum strength for a period of time after use, therefore - if samples are taken directly from the production line - they must be conditioned for at least 72 hours before testing.
5.2 Sample size
The minimum number of samples should be 2 for each type.
5.3 Sample preparation
5.3.1 Adhesive strength of the upper sole; type of construction (see Figure 1)
Cut a specimen from the inner or outer bonding area of the shoe's flexural area.
Using a punch or saw (see 4.1), cut the specimen at right angles to each other from X-X and Y-Y and to the edge of the sole, through the upper, insole or outsole, to a width of approximately 25 mm. The length of the upper and sole should be approximately 15 mm from the sub-mouth line (see Figure 2). Exclude the insole.
5.3.2 Adhesive strength of the sole; construction types b, c, d and e (see Figure 1)
Cut a specimen from the inner or outer bonded area of the shoe zigzag area.
Cut the upper and sole from X-X and Y-Y to make a specimen approximately 10 mm wide and with an effective peel length. Remove the inner sole. Insert the adhesive layer with a hot knife. Peel off the upper and sole by 10 mm to -20 mm (see Fig. 3).
Note. A structure with a distance of not less than 8 mm from the X-X to the upper surface of the insole is type. or type d. 5.3.3 Strength of interlaminar bonding of the sole compound; structure types f and g (see Fig. 1)
Cut a specimen from the inner or outer bonding area of the shoe zigzag area.
Cut along the sub-mouth line at X-X, removing the upper, if there is an insole and other components, e.g. along the strip, are removed. Cut parallel to and including the edge of the sole from Y-Y to make a strip approximately 15 mm wide and not less than 50 mm long.
A hot knife is inserted between the layers to separate them by 10 mm to 20 mm (see Figure 3).
6 Test method
6.1 Principle
The force required to peel the upper from the sole is measured using a pulling machine that can continuously record the pulling force.
6.2 Procedure
6.2.1. Before the test, measure the width of the specimen to an accuracy of 1 mm, measure 5 points with a measuring tool with an accuracy of 0.5 mm and calculate the average value A to an accuracy of 1 mm,
6.2.2 Measure the adhesive strength of the bottom of the gang according to the following method.
6.2.2.1 Adhesive strength of the bottom of the gang; type of constructiona.
The specimen was clamped onto the fixture of the pulling machine and the short edge of the sole was held in a vice (see Fig. 4) at a peeling speed of 100 mm/min ± 20 mm/min. After testing, the damage to the peeled surface was observed and classified according to 7.2.
6.2.2.2 Adhesion strength of the sole; structure types b, c, d, e, interlayer bonding strength of the sole; structure types f, g-
The peeled end of the specimen was clamped with a flat jig at a speed of 100 mm/min ± 20 mm/min and the force-deformation curve was recorded (see Figure 5). After testing, the peeled surface was observed for damage and classified according to 7.2.
7 Presentation of results
7.1 Determination of the adhesive strength of the bottom of the gang
Calculate the bottom bond strength (R [in N per millimetre (N/mm)] using equation (1>).
Where;
F - average force in N (N), from the basis
F - average force in N, determined from the force-deformation diagram recorded in accordance with 6.2.2.2
A - average width in millimetres (mm), determined according to 6.2.1.
The results are accurate to 0.1 N/mm.
Note. For shoes with multiple construction types on the adhesive edge of the upper sole, different test operations are carried out for different construction types. After 10 mm of peeling, start recording
The tensile force and the corresponding bond edge type are recorded. Calculate the adhesive strength of the sole at this point (R,).
Calculate the average value of R,.
7.2 Assessment of the damage pattern of the adhesive layer
The damage to the peeling interface of the specimen (see 6.2.2) should be classified according to the following designations
a) Separation of the adhesive layer from one of the materials (adhesion damage, see Figure 6), code A.
8 Test report
The test report should contain the following information:
a) indication of the use of this document
b) the characteristics of the sample (material, type of shoe, type of construction)
c) the values obtained for each test piece (maximum, minimum, average); d) the width of the bonded edge for each sample
e) Adhesive strength of the sole (N/mm) for each sample;
f) Peel interface damage type code;
g) ageing procedure (if applicable) and all conditions or details that can influence the results, even if not mentioned in this document; h) differences from this test method
i) the date of the test.
Appendix A (normative) Ageing treatment conditions for the test of adhesive strength of the underlayment
A.1 Overview
This appendix specifies the ageing conditions for the adhesive strength test of the underlayment.
A.2 Principle
The accelerated thermal ageing treatment is used to determine the change in bond strength measured in accordance with Chapter 6 in order to assess the quality of the bond after ageing.
A.3 Samples
Chapter 5 specifies the preparation of ageing samples. The initial bond strength of the sample prior to ageing should be determined in advance.
A.4 Apparatus
A.4.1 Circulating air oven, capable of maintaining a temperature of 5o ℃± 2 ℃or 70 ℃± 2 °C. A.4.2 Specimen holding device.
A.5 Accelerated ageing conditions
A.5.1 Standard ageing conditions
Place the specimen in a forced circulation oven (see A.4.1) at a temperature of 50 ℃ ± 2 ℃for a period of d. The specimen should avoid contact with the walls of the oven. After ageing, the specimens should be conditioned according to ISO 18454 for 24 h prior to the bond strength test.
A.5.2 Production control
For production control, the following conditions can be used to obtain quick results;
The specimens are placed in a forced circulation oven (see A.4.1) at a temperature of 7o ℃± 2 ℃for 72 h.
After the ageing treatment, the specimens should be conditioned for 24 h in the standard environment according to ISO 18454 prior to the bond strength test.
Bibliography
1 Scope
2 Normative references
3 Terms and definitions
4 Apparatus and materials
5 Sampling and adjustment
6 Test method
7 Presentation of results
8 Test report
Appendix A (normative) Ageing treatment conditions for the test of adhesive strength of the underlayment
Bibliography
