This standard specifies the determination method of full thickness tensile strength, reference force elongation and breaking elongation of fabric core conveyor belts. This standard is only applicable to fabric core conveyor belts. GB/T 3690-1994 Determination method of tensile strength and elongation of fabric core conveyor belts GB/T3690-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination method for tensile strength and elongation of fabric core conveyor belts
Conveyor belts ol. textlle carcaseTest method for tensile stregth and elongationGB/T 3690—94
Replacement GB 3690—83
This standard is equivalent to the test method part of the international standard IS0 283—1990 (Specification and test method for full-thickness tensile strength and elongation of conveyor belts).
1 Contents and applicable scope
This standard specifies the determination method for full-thickness tensile strength, reference force elongation and elongation at break of fabric core conveyor belts. This standard is only applicable to fabric core conveyor belts.
2. 1. Full thickness tensile strength: the ratio of the force required to break the specimen to the original tensile strength of the specimen when the full thickness specimen is subjected to a tensile test. 2.2 Elongation at break: the elongation of the specimen when subjected to a tensile force in a tensile test. 2.3 Elongation at break: the elongation of the specimen when it is broken in a tensile test. 3 Test data
The test instrument is a tensile testing machine that meets the following requirements. 3.1 The working speed of the dynamic clamp should be 100±10 mm/min, but the speed should be basically constant during a test. 3.2 The clamp should ensure that the specimen is well fixed and neither slipping nor clamping occurs during the entire test. 3.3 The accuracy of the testing machine is an error of no more than 2% of the measured force or 0.4% of the range, whichever is greater. This test should use a non-chronic force gauge (such as electronic or optical). When using an inertial dynamometer, the measured force should be limited to 15%~85% of the range.
4 Test specimens
4.1 Shape and size
There are three basic test specimen shapes, namely type A, type B and type C, as shown in Figure 1, Figure 2 and Figure 3 respectively. Instructions for use:
1) ISO283 does not have this provision,
User Technical Supervision 1994-01-D2 Approved 1994-10-01 Implementation
4.2 Quantity
GB/T 3690—94
22 *2 pieces
Type A test specimen
Type B test specimen
Minimum value
Figure 3 Type C test specimen
3 longitudinal test specimens. If necessary, 3 transverse test specimens. 4.3 Preparation method
Central position
4.3.1 The conveyor belt sample should be cut at a position at least 50mm away from the belt edge and without joints. The distance from the longitudinal edge of the sample to any edge of the sample shall not be less than 12mm. The longitudinal centerline of the longitudinal sample shall be parallel to the longitudinal centerline of the belt, and the transverse centerline of the transverse sample shall be perpendicular to the longitudinal centerline of the belt.
GB/T 3690-94
4.3.2 The cut surface of the sample should be neat and smooth, and strive to be perpendicular to the belt surface. The cutting knife blade angle should not exceed 18 (see Figure 4). The cutting knife is allowed to be wetted with water before cutting.
Figure 4 Cutting knife blade angle
4.3.3 If necessary, the covering layer of the sample is allowed to be ground or removed. 4.3.4 Draw two marking lines on the sample perpendicular to the longitudinal centerline and equidistant from the center, with a marking length of 100mm. 4.3.5 Measure and record the actual width of the narrowest part of the middle of the specimen, accurate to 0.1mm, and take the arithmetic mean of the upper and lower widths as the middle width of the specimen.
5 Conditioning of specimens 1
5.1 The shortest time interval between product vulcanization and testing is 16h. Before testing, the specimen shall be conditioned at the test temperature for no less than 3h. In case of dispute, the parking time shall be extended to at least 14d, and the specific time shall be agreed upon by the relevant parties. 5.2 The temperature condition of the test shall be 23±2℃. 6 Test procedure
6.1 Clamp the two ends of the specimen on the two clamps of the testing machine respectively, and the longitudinal center line of the specimen shall be consistent with the direction of the force line. When using type A specimen, the distance between the two clamps shall be 200±10mm. When using type B or type C specimen, the outer edge of the clamp shall be located approximately 10mm from the end of the specimen.
6.2 Continuously stretch the specimen at a speed of 100±10mm/min. 6.3 When the tensile force increases to the reference force and the fracture occurs, record the instantaneous tensile force and the distance between the markings respectively. 6.4 The fracture should occur between the two markings of the specimen. If the specimen is found to slip, or the fracture occurs outside the markings, or if a fabric joint is found within the markings of the specimen, the specimen shall be tested and another specimen shall be taken for retesting. 7 Test results
7.1 Calculation of results
7.1.1 The full-thickness tensile strength is calculated according to formula (1): F
Where: a-
Full-thickness tensile strength, N/mmwwW.bzxz.Net
F—Tensile force when the specimen is pulled apart, N
b——Medium width of the specimen, mm.
Instructions for use:
. (1)
1) According to IS0283, the specimens shall be selected from products that have been aged for at least 5 days and shall be conditioned for 3 days at a temperature of 23+2°C and a humidity of (50±5)%.
GB/T3690-94
7.1.2 The reference force elongation and the elongation at break shall be calculated according to formula (2) and formula (3) respectively: L=×100
Where: — reference force elongation, %,
e—— elongation at break, %
Lo—initial gauge length of the specimen, mm
Li—the distance between the gauge lines when stretched to the set force, mmLg—the distance between the gauge lines when the specimen is broken, mm. 7.2 Result Expression
7.2:1 The test results of the tensile properties of fabric core conveyor belts include ×100
. For longitudinal specimens: tensile strength (rounded), elongation at break (rounded), elongation at reference force (rounded); b. For transverse specimens, tensile strength (rounded). 7.2.2 The arithmetic mean of the results of three specimens is used as the test result for each item in the tensile properties. 8 Test Report
The test report shall include the following contents:
The variety, specification, batch number and manufacturer name of the test conveyor belt; test results;
Test model (indicate that the test is conducted on the male layer of the apricot belt), parking time;
Test room temperature,
Test date:
Tester.
Additional Notes:
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Beidao Rubber Industry Research Institute. This standard was drafted by the Ikushima Rubber Industry Research Institute and the Shenyang Rubber Belt Factory. The main drafters of this standard are Zhang Xiuxiang, Wang Sumei, Han Deshen, Zhuang Zang, and Wang Yunfa. (2)
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