This standard applies to the accelerated aging and heat resistance test of vulcanized rubber or thermoplastic rubber under normal pressure. GB/T 3512-2001 Accelerated aging and heat resistance test of vulcanized rubber or thermoplastic rubber under normal pressure. GB/T3512-2001 Standard download decompression password: www.bzxz.net

ICS83.060
National Standard of the People's Republic of China
GB/T 3512--2001
Rubber, vulcanized or thermoplastic-Accelerated ageing and heat resistance testsAir-oven method2007-08-28Promulgated
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
Implementation on 2002-05-01
National Standard of the People's Republic of China
Rubber, vulcanized or thermoplastic-Accelerated ageing and heat resistance testsAir-oven method 2001
Published by China Standards Press
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Printed by Qinhuangdao Printing Factory of China Standards PressDistributed by Beijing Distribution Office of Xinhua BookstoreSold by Xinhua Bookstores in various placesFormat 880×12301/16Printing Sheet 1/2Word Count 9,000WordsFirst Edition in February 2002First Printing in February 2002Print Quantity 1-2,000
Book Number: 1550661-18153Price 6.00 YuanWebsite www. bzrbs.com
Subject 593-541
Copyright reserved
Infringements must be investigated
Report phone number: (010)68533533
GB/T 3512-2001
This standard is equivalent to the test method B in the international standard ISO188.1998 "Heating aging and heat resistance test of vulcanized rubber or thermoplastic rubber", and revises GB/T3512-1983 (1989) "Rubber hot air aging test method". The technical content of this standard is basically the same as that of the test method B in ISO188:1998. The differences between this standard and GB/T3512-1983 (1989) are as follows: The name of the previous version is changed to "Hot air accelerated aging and heat resistance test of vulcanized rubber or thermoplastic rubber". This standard adds the provisions for the temperature control accuracy and aging time of the aging chamber. Appendix A of this standard is a reminder appendix. This standard replaces GB/T 3512-1983 (1989) from the date of implementation. This standard is proposed by the State Bureau of Petroleum and Chemical Industry. This standard is under the jurisdiction of the Rubber General Physical Test Method Sub-Technical Committee of the National Rubber Standardization Committee. The drafting unit of this standard is Guangzhou Synthetic Materials Research Institute. The main drafters of this standard are Xie Yufang and Zheng Yunzhong. This standard was first issued in March 1983 and confirmed in 1989. National Standard of the People's Republic of China
Rubher ,vulcanized or thermoplastic-Accelerated ageing and heat resistance tests-Air-oven methodGB/T 3512-2001
Replaces GB/T 3512-1983 (1989)
Warning: Personnel using this standard should be familiar with formal laboratory operating procedures. This standard does not intend to involve all safety issues that may arise from the use of this standard. It is the user's responsibility to develop appropriate safety and health systems and ensure compliance with national laws and regulations. 1 Scope || tt || This standard applies to hot air accelerated aging and heat resistance tests of vulcanized rubber or thermoplastic rubber under normal pressure. 2 Referenced standards || tt || 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 parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T2941:1991 Standard temperature, humidity and time for environmental conditioning and testing of rubber specimens (IS) 471:1983) GI3/T9865.1-1996 Preparation of samples and test pieces of vulcanized rubber or thermoplastic rubber - Part - Physical tests (IDT1S () 4661-1:1993)
GB/T14838-1993 Rubber and rubber products test methods - Determination of standard precision (nc9. IS/TR9272:1986) 3 Principle
The properties of the specimens are determined after aging in air at elevated temperature and atmospheric pressure, and compared with the properties of the unaged specimens. The physical properties related to use should be used to determine the degree of aging, but in the absence of exact identification of these properties, it is recommended to determine the tensile strength, secondary stress, elongation at break and hardness. 3.1 Hot Air Agingwww.bzxz.net
In this test method, the oxygen concentration is so low that even if oxidation is rapid, oxygen cannot diffuse sufficiently into the rubber to maintain consistent oxidation. Therefore, when specimens of the thickness specified in the standard test method are suitable for use with this test method, this aging test method may give erroneous results for rubber with poor aging properties. 3.2 Heat Resistance Test
In this test method, the appropriate properties are determined after the specimens are subjected to the same temperature and specified time as in use and compared with the properties of the unaged specimens.
4 Test equipment
The rubber specimens are tested in a hot air aging box. The aging box should meet the following requirements: a) It has a forced air circulation device, with an air flow rate of 0.5m/s-~1.5m/s. The minimum surface area of ​​the specimen is facing the air flow to avoid interfering with the air flow rate.
b) The size of the aging box should meet the requirements that the total volume of the sample does not exceed 10% of the effective volume of the aging box, the spacing between the hanging specimens is at least\0mm, and the specimen is at least 50mm away from the aging box wall. mm;) There must be a temperature control device to ensure that the temperature of the sample is maintained within the tolerance range of the specified test temperature; d) There is a temperature measuring device in the heating chamber to record the actual heating temperature; e) Copper or copper alloys shall not be used in the heating chamber structure:) The air replacement frequency of the aging box is three to ten times per hour; g) The air should be heated to the tolerance range of the test temperature specified in the aging box before entering the aging box. 5. The preparation of test specimens shall comply with the provisions of GB/T98.1. 5.1 5.2 Hot air accelerated aging and resistance tests shall use specimens that have been conditioned in accordance with the provisions of GB/T2941. Incomplete products or test pieces shall not be used. 5.3 The aged specimens shall not be treated, chemically or thermally. 5.4 The number of specimens before aging and after aging is usually five, but not less than three. 5.5 Only specimens with the same size can be compared. Whenever possible, they should be marked after aging. Marks cannot be used on any critical surface of the test specimens. Measure before heating and do not damage the specimens. They will be decomposed during heating. In order to prevent the migration of sulfur, antioxidants, peroxides or plasticizers, it is recommended that only materials of different types can be heated together in the same aging cabinet: a) rubber of the same type; b) rubber containing the same accelerator or similar ratio of sulfur and accelerator; c) rubber containing the same antioxidant; d) rubber containing the same type and amount of plasticizer; 6 The time interval between vulcanization and testing shall comply with the provisions of GB/T/7 Test Conditions 7.1 Overview.
The time required for the sample to obtain the degree of aging in the test depends on the type of rubber sample. The test cycle used should ensure that the aging of the sample does not reduce the degree to hinder the final determination of the physical properties of the sample. If the degradation mechanism caused by high temperature aging is different from the degradation mechanism occurring at the operating temperature, the test result is invalid. 7.2 Hot air accelerated aging
The test temperature shall be selected in accordance with the provisions of GB/T2941 or agreed upon by relevant personnel: the aging time shall be selected as 24.48, 72, 96, 168h or multiples of 168h.
7.3 Heat resistance test
The test temperature shall be in accordance with the provisions of GB/T2941 or agreed upon by the relevant personnel. The test temperature shall be representative of the use temperature of the sample. The aging time can be selected as 24, 48.72, 96.168h or multiples of 168h. 8 Procedure
8.1 Adjust the aging box to a test temperature, and hang the sample in the aging box in a self-exposed state for testing. 8.2 The aging time starts to be calculated when the sample is placed in the aging box. When the specified time is reached, the sample is taken out. 8.3 The sample taken out is subjected to environmental conditioning for 16h~144h in accordance with the provisions of GB/T2941. 8.4 The determination of relevant properties shall be carried out in accordance with the provisions of the corresponding test standards. 9 Result expression
The performance change rate is calculated according to formula (1):
Where: P
Performance change rate, %,
Performance measurement value of the sample after aging;
X. Performance measurement value of the sample before aging.
9.2 Hardness change is calculated according to formula (2):
Where: H
10 Precision
Hardness change:
Hardness value after aging,
Hardness value before aging.
GB/T 3512—2001
H - X,- X.
The precision of repeatability and reproducibility is in accordance with the provisions of GB/T14838, which describes the concept and terminology of precision. The appendix (indicative appendix) plays a guiding role in the application of repeatability and reproducibility results. 11 Test report
The test report should include the following:
a) The name and code of this standard adopted;
b) Sample description:
1) The name, specification, quantity and source of the sample; 2) If known, the composition of the rubber mix and its vulcanization conditions; 3) The time interval between vulcanization and testing;
4) Sample preparation method (e.g. molding: cutting the sample from the sample); c) Aging description:
1) Aging box model;| |tt||2) is it an accelerated aging or heat resistance test;
3) the test performance and the type of specimen used; 4) the aging test temperature and time;
d) test results:
1 the number of specimens used;
2) each performance value before and after aging can be tested by an appropriate performance parameter expressed in this standard; 3) expressed as the rate of change of performance, while hardness is expressed as the difference between two values; e) the date of the test;
f) the tester;
g) the auditor.
(1)
GB/T 3512—2001
Appendix A
(Indicative Appendix)
Guide to the use of precision results
A1 The general procedure for using precision results is as follows, using the symbol /X, -X1 to represent the positive difference between any two measured values. A2 Look up the appropriate precision table (regardless of the test parameter under consideration) and draw a line at the point where the average value of the measured parameter is closest to the average value of the test data under investigation. This line will give the corresponding (r), R or (R) used in the judgment process. A3 The following general repeatability statements and corresponding R and (R) values ​​can be used to judge precision. 43.1 Absolute difference: The difference between the average values ​​of two tests obtained with samples of the same labeled material under normal test procedures [X1-X,1, on average, shall not exceed the tabulated repeatability more than once in every 2 drinks. 43.2 Percent difference between the average values ​​of two tests: The percentage deviation between two test values ​​obtained with samples of the same labeled material under normal and correct test procedures.
CIX, - X,1/(1-+ X,)/21 X 100 on average shall not exceed the tabulated repeatability more than once in every 20 times. A4 The following general reproducibility statements and corresponding R and (R) values ​​can be used to judge precision. 44.1 Absolute difference: The absolute difference between the mean values ​​of two independent tests obtained by using normal and correct test procedures in two laboratories and using samples of the same label material is 1X1-X21, which shall not exceed the listed reproducibility RA more than once in every 20 times on average. 4.2 The percentage difference between the mean values ​​of two tests: The percentage deviation of the mean values ​​of two independent tests obtained by using normal and correct test procedures in two laboratories and using samples of the same label material is CX, - Xz1/(X, + X,)/2] X 100, which shall not exceed the listed reproducibility (R) more than once in every 20 times on average. Copyright exclusive infringement must be investigated
Book number: 155066: 1-18053
Price:
GB/T3512-2001
Science H593541)/2] X 100 No more than one drink in every 20 times shall exceed the listed reproducibility (R). Copyright exclusive infringement must be investigated
Book number: 155066: 1-18053
Price:
GB/T3512-2001
Science H593541)/2] X 100 No more than one drink in every 20 times shall exceed the listed reproducibility (R). Copyright exclusive infringement must be investigated
Book number: 155066: 1-18053
Price:
GB/T3512-2001
Science H593541
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