This standard specifies the test method for the bond strength between the cord and rubber in V-belts. This standard is applicable to all kinds of cord V-belts. GB/T 3688-1998 Test method for bond strength of V-belt cords GB/T3688-1998 Standard download decompression password: www.bzxz.net

GB/T3688—1998
This standard is equivalent to the "Test of Adhesion Strength of V-Belt Cords" in the technical conditions of advanced foreign companies. This standard has revised GB/T3688—1983 "Test Method of Adhesion Strength of V-Belt Cords and Rubber", and changed the specimen length from 25mm in the original standard to 10 mm.
This standard replaces GB/T3688—1983 from the date of implementation. This standard was proposed by the former Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Ministry of Chemical Industry's adhesive tape standardization technology unit. The drafting units of this standard are: Qingdao Rubber Industry Research Institute, Hebei Xinji Rubber Factory, Ningbo Synchronous Belt General Factory, Zhejiang Tiantai Tianlong Rubber Co., Ltd., and Xinjiang Production and Construction Corps Third Transportation Company Rubber Factory. The main drafters of this standard are: Han Deshen, Shen Huijie, Lin Qifu, Xu Heping, and Yang Ruiling. This standard was first issued in May 1983.
1 Scope
National Standard of the People's Republic of China
V-belts-Cord adhesion test method
V-belts-Cord adhesion test method This standard specifies the test method for the adhesion strength between the cord and rubber in V-belts. This standard is applicable to all kinds of cord V-belts.
2 Referenced standards
GB/T3688-1998
Replaces GB/T3688--1983
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards. HG/T2369-1992 Technical conditions for rubber and plastic tensile testing machine 3 Principle
The adhesion strength between the cord and rubber refers to the adhesion strength between the cord and the bottom rubber and top rubber. This value is related to the measurement of the power transmission and flexural performance of the V-belt. In order to determine the bonding strength, a cord located in the center is pulled out from a certain length of the V-belt, and the maximum extraction force in this process is measured. The maximum extraction force per unit length is the bonding strength. 4 Apparatus
4.1 The tensile testing machine used in the test should meet the requirements of HG/T2369. 4.2 The upper clamp is replaced with a device for supporting the specimen, a supporter (see Figure 1). The opening width of the supporter in Figure 1 is 2.2mm, which is suitable for V-belts with a cord diameter not exceeding 2.0mm. The test supporter for V-belts with larger cord diameters can refer to the above regulations. 4.3 The lower clamp should be able to firmly clamp the cord, and the working speed during the test is 100mm/min. Approved by the State Administration of Quality and Technical Supervision on October 19, 199834
Implemented on April 1, 1999
5 Test specimens
GB/T3688---1998
Figure 1 Supporterbzxz.net
5.1 Cut five test specimens of about 200 mm in length from the V-belt. 15
5.2 Process each test specimen, i.e., keep a 10 mm long section of the V-belt with embedded cords intact, and remove the remaining material except for one center cord. The length of the exposed center cord is about 180 mm. 5.3 The test specimens shall be kept at a test temperature of 23°C ± 2°C for more than 24 hours. 6 Procedure
6.1 Place the sample on the support so that the exposed center cord hangs down from the opening of the support. Clamp the cord into the lower clamp and adjust the position of the sample in the support so that the cord is located in the center of the opening width and the center of the cord is consistent with the direction of the force line. 6.2 Start the testing machine and pull the cord until it is completely pulled out. Record the maximum extraction force applied to the sample during the pulling process. 6.3 Then test the remaining four samples one by one. 7 Interpretation of results
7.1 Based on the 10mm cord pull-out length and the measured maximum pull-out force, calculate the maximum pull-out force per unit length, which is the bonding strength.
7.2 The arithmetic mean of the bonding strengths of the five samples is taken as the test result. 8 Test Report
The test report shall include the following contents:
a) the number of the standard on which the test is based,
b) the type, specification, batch number and manufacturing unit of the tested V-belt;
c) the test results of the bonding strength,
d) the storage time and the temperature of the test room;
e) the tester and the test period.
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