HG/T 2724.4-1995 Test method for rubber threads Determination of stress retention rate HG/T2724.4-1995 Standard download decompression password: www.bzxz.net
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Chemical Industry Standard of the People's Republic of China HG/T2724.4—1995 idt ISo2321:1983 Test Method for Rubber Thread Determination of Stress Retention Rate Published on June 30, 1995 Ministry of Chemical Industry of the People's Republic of China Implementation on January 1, 1996 This standard is formulated in accordance with the tenth part of the international standard ISO 2321:1983 "Rubber Thread--Test Method", and is equivalent to it in terms of technical content and writing rules. By adopting the international standard, the test method for the stress retention rate of rubber thread in my country is formulated, which also provides a method standard for the determination of the stress retention rate in the formulation of rubber thread product standards. Figure 1 is a reference to the instrument in ISO2321 and has made some improvements. A tension sensor is used, and a digital display instrument is added to replace the spring tension meter. The reading is intuitive and the error is small; the wire clamp is omitted, and the lower mark pile is 10mm1~20mm longer than the upper mark pile. When reading, you only need to translate the rubber wire ring to the hook of the lower mark pile and the sensor. The operation is convenient. This standard is proposed by the Technical Supervision 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. Drafting unit of this standard: Latex Industry Research Institute of the Ministry of Chemical Industry The main drafters of this standard Kang Ronghua Wensi Zhengdou Yingyuan ISO Foreword ISO (International Organization for Standardization) is a worldwide federation of national standards associations (ISO member groups). The work of formulating international standards is carried out through ISO technical committees. Any member group interested in the project established by the technical committee has the right to participate in the committee, and any governmental and non-governmental international organization that has a relationship with ISO can participate in this work. Draft international standards adopted by the technical committees should be circulated to the member bodies for their approval before they can be approved as international standards by the ISO Council. International Standard ISO 2321 was prepared by ISO/TC 45 Technical Committee Rubber and rubber products. This second edition was submitted directly to the ISO Council in accordance with clause 6.11.2 of Part 1 of the ISO Technical Work Directives: The second edition replaces the first edition (ISO 2321:1975) and was approved by the following national member bodies: Belgium Bulgaria Canada Czechoslovakia Federal GermanybZxz.net Ireland Israel Italy The following national members expressed disapproval of this document for technical reasons: United States Portugal Romania This international standard also replaces Annex 1—1975. Annex 2-1980 and Annex 3—1980.1 Scope Chemical Industry Standard of the People's Republic of China Test method for rubber filaments Determination of stress retention rate This standard specifies the test method for the stress retention rate of rubber filaments. This standard applies to rubber threads made of natural rubber and synthetic polyisoprene rubber 2 Cited standards HG/T 2724.4-1995 idt IS0 2321: 1983 The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When the standard is revised, the versions shown are valid. All standards will be revised. Parties using this standard should explore the possibility of using the latest versions of the following standards. GB2941--91 Rubber test environment conditioning and test standard temperature, humidity and time (ISO471: J983, ISO1826: J981) HG/T2724.7--1995 Rubber thread test method determination of fixed stress (ISO2321: 1983) 3 Definition This standard adopts the following definitions: Stress retention rate The residual load after the specimen is maintained at a constant stress ratio (usually 100%) for a specified time is calculated as a percentage of the initial load. 4 Device This test adopts the simple device shown in Figure 1, which mainly consists of the following components: Approved by the Ministry of Chemical Industry of the People's Republic of China on 199S-06-30 and implemented on 1996-01-01 HG / T 2724. 4 —1995 1—Retaining frame; 2—Lower mark chain; 3—Rubber wire ring: 4—Upper mark 5—Hanging hook: 6 Pull pressure sensor: 7—Digital display instrument Figure】Determination device of stress retention rate a. Upper and lower mark stakes: Make the rubber wire ring with a circumference of 1001mm maintain 100% fixed length rate b. Sensor and digital display instrument: Fixed on the frame of the device shown in Figure 1, the initial load and residual load are read out of the digital display connected to the sensor. c. Hook: Connected to the sensor d. Cage, 5 Test specimen The test specimen shall comply with the provisions of HG/T 2724.7. 6 Test steps 6.1 Place the test specimen in accordance with the provisions of GB2941, 6.2 Prepare three test specimens with a circumference of 100±1mm.63 At room temperature, pass the end of each test specimen around the lower mark, and hang the other end on the 1 standard at a length ratio of (100±2)%. After the initial elongation of 30±1min, move the rubber wire ring horizontally to the lower mark and the hook connected to the sensor, read the machine value on the digital display instrument, and after keeping the specified time, read the residual load value in the same way as above. The result is expressed as 7.1 The test stress retention rate is expressed as a percentage, as follows: F is the initial load; - is the residual load. HG/T2724.4—-1995 7.2 The median value of three samples is used to represent the stress retention rate of the rubber wire. Test report The test report should include the following information: Source of the sample and identification mark; Standard based on which the test is conducted: Test temperature; Storage conditions and duration of the sample; Number of samples: If the elongation rate of the sample is not 100%, record the elongation of the sample; Test method and equipment used; Test results; Test date: Tester. 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