HG/T 2487-1993 Determination of elongation of rubber thread at a given load HG/T2487-1993 Standard download decompression password: www.bzxz.net

Chemical Industry Standard of the People's Republic of China
Determination of elongation of rubber thread under set tensile load This standard is equivalent to the international standard ISO2321-1983 "Rubber thread subject content and scope of application
This standard specifies the determination method of elongation of rubber thread under set load, HG/T2487-93
-Test method" Part 10.
This standard is applicable to rubber threads made of natural rubber, natural latex and synthetic isoprene rubber. 2 Reference standards
HG/T2412.2 Test method for rubber thread Determination of rubber thread count HG/T2412.3 Test method for rubber thread Determination of rubber thread density HG/T2488 Test method for rubber thread Rubber Determination of tensile properties of rubber wire 3 Definition
Constant load elongation is the percentage of elongation of rubber wire when a certain load is applied to a unit area to generate stress. A certain load is applied to the rubber wire that is not affected by external forces to determine the influence of rubber wire aging, storage and environment. Usually two loads, namely 1.55MPa and 2.74MPa, are used for determination. 4 Test device
4.1 The device can stretch the sample at a constant speed until it reaches a predetermined load, and in order to read the elongation, the device should be equipped with a scale. 4.2 The applicable device shown in the figure can be used, or the equipment described in 3.1 of HG/T2488 can be used. The test device used should be specified in the test report.
4.3 The applicable device shown in the figure consists of the following parts:. A scale for reading the elongation of the sample b. Two clamps for clamping the ends of the sample. The length between the clamps is 150 to 2mm in the initial state: The upper clamp has a device that moves in the vertical direction at a speed of 30±10mm/s to stretch the sample. The plate connected to the lower fixture is used to add the necessary weight to make the load adapt to the rubber wire being tested. The electric switch is close to the bottom of the plate. When the force applied when stretching the rubber wire exceeds the weight of the plate, the plate will rise so that the switch can stop the motor and start the brake. Instructions for use:
13The two devices specified in 10.3.2 of ISO2321-83 are not parallel. The equipment that meets HG/T2488 appears in the form of a note. Approved by the Ministry of Chemical Industry of the People's Republic of China on July 5, 1993 and implemented on December 1, 1994
5 Test specimen
HG/T2487
In the instrument for measuring elongation under specified load 2
, a scale: ② a fixture; @ a code; @ an electric switch,
5.1 Use a rigid fixture device: prepare a rubber wire sample with a length of 125 to 150 mm. A single or multiple rubber wires can be used as a sample, and an initial length of 50 mm is marked with a water mark. 5.2 Use the device shown in the figure: One or more rubber wires can be used as a sample, and an initial length of 150 ± 2m is marked. 6 Test steps
6.1 According to the selected load value, use the methods of HG/T2412.2 and HG/T2412.3 to calculate the tensile load value to be indicated on the tensile machine.
6.2 Use the test device as shown in the figure to prepare three specimens. Fix the ends of each specimen on the fixture in turn. The length between the fixtures is 150±2mm in the initial state. Add the specified amount to the pan, start the motor, and when the switch stops the motor automatically, measure the elongation of the sample on the ruler.
6.3 Use the equipment described in 3.1 of HG/T2488, fix the sample according to 5.1.2, 5.1.3 and 5.1.4 of the standard, start the motor, stop immediately when the dynamometer reaches the specified load, and measure the length between the two marks on the sample. 7 Result expression
7.1 The elongation at fixed load is expressed as a percentage and is calculated as follows: Lo
Where: A-
Elongation at fixed load, %;
-initial gauge length of the sample, mm;
HG/T2487—93
L—length between the two marks of the sample when the specified load is reached, mm. 7.2 The median of the test results of three specimens is taken to represent the elongation under the specified load. 8
Test report
The test report should include the following contents:
The source and identification mark of the specimen;
The standard and standard number based on which the test is conducted;
Test humidity and humidity:
Number of specimens:
Test method and device adopted;
Specified load;www.bzxz.net
Test results;
Test date;
Tester.
Additional remarks:
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Latex Industry Research Institute of the Ministry of Chemical Industry. This standard was drafted by Shenyang Latex Factory. The main drafters of this standard are Liu Wei, Zheng Jingru and Liu Chunhong.
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