Some standard content:
Chemical Industry Standard of the People's Republic of China
HG /T 2411 -- 92
Test method for 90° flexion of sole materials
Published on October 22, 1992
Ministry of Chemical Industry of the People's Republic of China
Implemented on July 1, 1993
Chemical Industry Standard of the People's Republic of China
Test method for 90° flexion of sole materials
HG/T2411--92
This standard adopts the appendix of the international standard ISO4643-1980 "Plastic molded shoes---Specification for polyvinyl industrial boots" B. 1 Subject content and scope of application
This standard specifies the test method for the growth of cracks in thermoplastic elastomer materials such as PVC, modified PVC, SBS, polyurethane, etc. during repeated bending.
This standard is applicable to the measurement of the fracture resistance of sole materials caused by wearing bending. 2 Reference standards
GB/T.2941 Standard temperature, humidity and time for environmental conditioning and testing of rubber specimens GB/T3512 Rubber hot air aging test method 3 Principle
The specimen is repeatedly wound 90 degrees on the core rod. Bending makes the small incision grow. The growth rate of the incision is the measure of the new crack tendency of the specimen.
4 Instruments
4.1 The working principle of the flexure tester is shown in Figure 1 (a, b). 4.2 Insert the specimen A into the baffle close to the end of the bending arm B and fix it with a clamp C: its clamping length JK is 50 ± 0.5m. The other end of the specimen can move between the positioning cylinder, shafts P, E and F during the test. The deflection is generated around the core shaft H. The radius of the core is 5.0 ± 0.3mm. The horizontal distance between the edges of G and C adjacent to the core shaft is 11.0 ± 0.5mm. The specimen is pre-cut at G. In the test tree, the incision is located above the edge of the core shaft. 4.3 The tangent points of the upper edges of the positioning cylinder, shafts E and F and the core shaft H are all in the same horizontal plane. The upper positioning cylinder D is directly above the lower positioning cylinder E. The size and position of the positioning shaft, shaft D, E and F are not strictly required. The diameter of D and E is 25mm and the diameter of F is 15nim. The center distance between E and F is 30mm, the center distance between E and H is 25mm, and the maximum distance between D and E is 30mm. The vertical position of D is adjustable so that it can meet the needs of specimens of different thicknesses. When the distance is adjusted, there is a locking mechanism to ensure that the gap does not change during the test.
4.4 There are two adjustable collars L on the rear positioning shaft F. When installing the specimen, the collar plays a role in limiting the positioning of the unclamped end of the specimen: the specimen is at a right angle to the arm B in the plane. During the test, this right angle position is maintained. The difference between the inner and outer diameters of the collar is 10mm.
4.5 The frequency is 1.0±0.1Hz.
4.6 The overflow of the low-temperature box should be kept at -5±2 for testing, and the transmission motor of the flexure machine should be installed outside the low-temperature box. 4.7 Piercing chisel, with which to make a cut in the specimen. See Figure 2. The chisel width is 2 ± 0.05 mm. Approved by the Ministry of Chemical Industry of the People's Republic of China on October 22, 1992 and implemented on July 1, 1993. HG/T2411-92. Adjustment and locking mechanism of roller D (plus the frame supporting the mechanism). Position of the complete opening of roller B and specimen A (C omitted). |Side view of the bending arm and the positioning shaft
Specimen,
Figure 1b Top view of the specimen, the bending arm and the positioning shaftA-specimen: B-spindle; C-specimen fixture: D-adjustable upper positioning rod: E-lower positioning rod; F-rear positioning shaft; G-specimen cut; H-specimen bending mandrel; J-clamp C close to the cut G and the end face of the mandrel H K-specimen end: L-specimen collar on the F-shaft 5 Specimen preparation
HG /T 2411—92
2 Earth standard +5
Figure 2 Perforator
Dimensions in mm
Chamfer formed by file
From the tapered part to the chisel, the blade part of the double-turned knife 5.1 The width of the specimen is 25±0.5mm, the length is 50±1mm, and the thickness can be 2.0±0.2, 3.0±0.2, 5.0±0.2, 7.0±0.2.15.0±0.2mm.
HG / T 2411 — 92
5.2 The specimen can be cut from a plate of appropriate thickness. The longitudinal direction of the specimen should be parallel to the rolling or extrusion direction. If it is obtained from the sole, the upper and lower sides of the specimen should be cut and gently cut to reduce the thickness of the specimen to the standard thickness. 5.3 From one end of the specimen, 6±0.1mm, use a piercing chisel to make symmetrical cuts at the center line of the specimen. The cut must penetrate the specimen. However, when the thickness is above 10mm, the cut depth is allowed to be 7.5mm. 6 Storage and test temperature of the specimen
6.1 According to the provisions of GB/T2941, the specimen is stored at 23±2C for 24h and tested at -5±2. 6.2 The specimen can also be stored and tested according to the conditions of 6.1 after aging at 100t for 24h according to GB/T3512. 63 After 96h of injection molding, sampling can be carried out for testing. 7 Test steps
Adjust the test frequency to ensure normal operation at 1.0±0.1Hz. 71
7.2 Record the initial cut length of each sample with an accuracy of 0.5mm. Wrap the sample around a core shaft with a diameter of 15mm, bend it 45°, and use a magnifying glass and a ruler (with an accuracy of 0.5mm) to measure the length of the cut. 7.3 Manually make the flexion arm B horizontal, raise the upper positioning device D, remove the clamp C, insert the sample from the front between D and E, put the front end of the sample into the groove of the flexion arm, and press against the front end stopper. The rear end of the sample rests on the rear positioning shaft F, and the collar on F is adjusted so that there is a distance of about ±1m between it and the width of the sample. Check whether each sample is perpendicular to the core shaft H and whether point G is exactly at the horizontal edge of the core shaft H. Then clamp the fixture C and tighten it with a nut. If only one sample is installed in a set of sample fixtures, a small piece of sample with the same thickness as the test material should be installed in another groove so that the fixture C and the plane of the flexure arm can be balanced. Press down the soil positioning cylinder D so that it just touches the sample, but does not clamp the sample, and fix the upper positioning cylinder D. 7.4 After the sample is installed, adjust the temperature of the low temperature box to the test temperature of -5±27. 7.5 Preset the number of observations, start the motor for the test, and start the inspection once every hour (i.e. 3600 flexions). During the inspection, bend the flexion arm B to 45". Use a magnifying glass and a ruler to measure and record on the testing machine. 7.6 For the finished product inspection, after the flexion times required by the finished product index are reached, stop the machine and unload the sample, carefully measure the longest crack length, and then calculate the crack growth.
7.7 Determine the crack growth rate, or when the crack grows 6mm (i.e. cut When the total length of the crack is greater than 8mm), the test is stopped. 8. Results
8.1 If the longest test cycle is not reached and the crack grows more than 6mm, the number of flexures when the crack grows 6mm is used for reporting. The number of flexures can be calculated by graphical insertion or arithmetic insertion. 8.2 If the test reaches the maximum number of cycles and the crack grows less than 6mm, the actual measured value of the crack growth is used for reporting. &.3 Take at least two specimens from each specimen and take the arithmetic mean of the results. 9. Test report
9.1 Specimen number and specimen name.
9.2 Test date, test room temperature,
9.3 Preparation conditions of specimens, thickness of specimens, 9.4 Test temperature.
9. 5 Test results,
9.5.1 Test cycle number when the crack grows 6mm; 9.5.2 Crack growth value after reaching the specified number of test cycles 9.6 Tester's signature, the signature of the reviewer,
Additional instructions:
HG/T241I—92
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China, and this standard is under the jurisdiction of Shanghai Rubber Shoes Research Institute. This standard was drafted by Shanghai Rubber Shoes Research Institute, and the main drafters of this standard were Ni Weijun and Chen Lishan.
Chemical Industry Standard of the People's Republic of China
90° flexure test method for sole materials
HG/ T 2411 —92
Editor: Chemical Industry Standards Department
(Standardization Research Institute of Ministry of Chemical Industry)
Postal Code: 100013
Printer: Standardization Research Institute of Ministry of Chemical Industry
Copyright reserved. No reproduction allowed
Format: 880×12301/16 Number of words on a sheet: 9000 Edition: May 1993
First printing: May 1993
Number of copies: 1—500wwW.bzxz.Net
Cost: 1.40 Yuan
HG/T 2411 --92
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