GB/T 5564-1994 Low temperature flexure test for rubber and plastic hoses

This standard specifies two test methods for determining whether rubber and plastic hoses maintain suitable flexural properties at low temperatures. Method A: Low temperature rigidity test is applicable to non-folding hoses with an inner diameter of 25 mm or less (including 25 mm). This method is to determine the increment of hose rigidity at standard laboratory temperature to compare the flexural properties of the hose. Method B: Low temperature bending test is applicable to hoses with an inner diameter of 100 mm or less (including 100 mm). GB/T 5564-1994 Low temperature flexural test for rubber and plastic hoses GB/T5564-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Rubber and plastics hoses-Subembienttemperatureflexibilltytests
GB/T 5564-94
Replaces GR5564-85
This standard refers to and adopts the international standard ISO4672-1988 "Rubber and plastics hoses-Subembienttemperatureflexibilltytests". 1 Subject content and scope of application
This standard specifies two test methods for determining whether rubber and plastic hoses maintain suitable flexural properties at low temperatures. Method A: The low-temperature rigidity test is applicable to non-folding hoses with an inner diameter of less than 25mm (including 25mm). This method is to determine the increment of hose stiffness at standard laboratory temperature to compare the flexural properties of the hose. Method B: The low-temperature bending test is applicable to hoses with an inner diameter of less than 100mm (including 100mm). 2 Reference standards
GB2941 Standard temperature, humidity and time for environmental conditioning and testing of rubber specimens GB/T5563 Hydraulic test method for hoses
GB9868 General rules for rubber to obtain temperatures above or below the temperature of the test 3 Method A Low-stiffness test
3.1 Test apparatus
3.1.1 The diameter of the torque wheel is 2 times the bending radius of the hose or 12 times the nominal inner diameter of the hose. The wheel is equipped with a suitable device that allows the hose to bend around the wheel and maintain the tangential direction. In addition, a strain gauge and a chart recorder are installed to measure the torque of the disk with an accuracy of ±3%. 3.1.2 The low-temperature box is equipped with an agitator, a temperature measuring device and a hose guide with a diameter of 50mm (see figure). Approved by the State Administration of Technical Supervision on January 2, 1994 and implemented on October 1, 1994
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GB/T 5564-94
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Low Temperature Rigidity Test Device Diagram
3.1.3 Cooling shall not affect the hose to be tested and shall be used in accordance with the provisions of GB9868. Suitable coolants may be methanol or ethanol added with crushed dry ice (solid carbon dioxide). If the designed device can use gas cooling medium to test and obtain the same test results as liquid cooling medium, gas cooling medium may also be used. 3.2 Test specimens
3.2.1 Test specimen type
Take the test specimen from the tube to be tested, and the length of the cut specimen is: L = rR + 2d
Wherein, L is the length of the test specimen, mm
R is the bending radius of the hose in accordance with the relevant product standards, and md is the outer diameter of the hose, mm.
3. 2. 2 Quantity
At least 3 test specimens shall be used for each test.
This test shall not be carried out within 24 hours after the hose is produced. 3.3 Test temperature
The test shall be carried out at the following temperatures:
0±2℃, -10±2℃, -25±2℃, 40±2℃, -55±2℃. Or the test shall be carried out at other low temperatures determined by the relevant product standards. 3.4 Test procedure
Fasten one end of the hose sample to the clamp on the side of the torque wheel, and naturally place the straight or bent hose sample around the torque wheel. Under the standard test temperature specified in GB2941, measure the torque of the sample around the torque wheel 180°, and the twisting time is 12±2s. Fill the low temperature box with coolant to reach the test temperature, fasten one end of the hose sample to the clamp on the side of the torque wheel, and naturally place the straight or bent hose GB/T 556494 around the torque wheel. Park it at the test temperature for 6 hours, and measure the torque of the hose sample around the torque wheel 180°, and the twisting time is 122$.
3.5 Calculation and expression of test results
The average of the peak values ​​of the torque trajectory of the three samples at the 50% center line is taken as the average torque T at the standard temperature. and the average torque T, at the test temperature, and then substitute it into formula (2) to obtain the specimen stiffness SS
where: T, the average torque at the test temperature: T. — the average torque at the standard temperature.
If the torque of any specimen at each test temperature exceeds 15% of the average value T, at that temperature, the test shall be repeated. 3.6 Test report
The test report shall include the following:
The referenced national standard
Detailed description of the hose and its original data; specimen size;
The coolant used,
Standard temperature and test temperature;
The calculated value of the torque I stiffness at the standard temperature and test temperature
Test date;
4 Method
Low temperature bending test
4.1 Test apparatus
4.1.1 A mandrel with an outer diameter of twice the minimum bending radius of the hose or a mandrel with a width of at least 180°. If the minimum bending radius of the hose is not specified, the outer diameter of the mandrel or roller should be 12 times the nominal inner diameter of the hose. 4.1.2 The low temperature box should be able to maintain the specified temperature. 4.2 Test specimens
Cut the specimen from the hose to be tested. The length of the cut should be appropriate to ensure that it is 180° around the mandrel. Appropriate length should be left at both ends of the specimen so that it can be installed and fixed.
After the test is completed, the specimen is scrapped.
4.3 Test temperature
The test should be carried out at one of the following temperatures:
0±2℃, -10±2℃, 25±2℃, -40±2c, 55±2℃. Or the test can be carried out at other low temperatures determined by the relevant product standards. 4.4 Test procedure
Place the mandrel and the sample in a low temperature box at the selected test temperature for 6 hours. Do not take them out of the low temperature box. Bend the hose sample with an inner diameter of less than 22mm (including 22mm) around the mandrel by 180° within 10±2s. Bend the hose sample with an inner diameter greater than 22mm around the mandrel by 90° within 10±2s. When testing hose samples with an inner diameter greater than 22mm, it is allowed to test outside the low temperature box, but be careful not to increase the temperature of the sample during the test.
Observe whether the inner and outer rubber layers of the hose are cracked or damaged. After bending, restore the hose sample to ambient temperature and perform the test pressure test specified in GB/T 5563. Observe whether the outer and inner rubber layers of the hose sample are cracked or damaged. 4.5 Test report
The test report shall include the following contents:
The referenced national standard;bzxZ.net
Detailed description of the hose and its original data: size of the specimen;
Test temperature;
Results of the visual inspection of the specimen after bending; Results of the visual inspection of the specimen after the pressure test, description of the test procedure;
Test date;
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 the Rubber Hose Sub-Technical Committee of the National Technical Committee for Standardization of Rubber and Rubber Products. This standard was drafted by Shanghai Rubber General Factory. The drafters of this standard are Ji Wencai, Chen Yu, Zhou Guoliang, Wang Fusheng, and Yan Songfeng.
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