Original standard number GB 9571-88 HG/T 2869-1997 Rubber and plastic hoses--Evaluation of ozone resistance under static conditions HG/T2869-1997 Standard download decompression password: www.bzxz.net

HIG/T28691997 | 1988 "Evaluation of Ozone Resistance of Rubber and Material Hoses under Static Conditions"
This standard was 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 Hose Sub-Technical Committee of the National Technical Committee for Standardization of Rubber and Rubber Products. This standard was drafted by: Shenyang Rubber Industrial Products Research Institute, Ministry of Chemistry. The main drafter of this standard is Yan Songfeng.
IIG/T2869-1997
Pre-ISO
ISO (International Organization for Standardization) is a worldwide joint organization of national standards bodies (ISO) member units). The work of formulating international standards is usually carried out by ISO technical committees. All member groups interested in the establishment of a technical committee are entitled to participate in the committee. Governmental and non-governmental international organizations associated with 1SC) can also participate in this work. ISO cooperates with the International Electrotechnical Commission (IEC) in all aspects of electrotechnical standardization. Draft international standards adopted by technical committees are circulated to member groups for voting. When published as an international standard, at least 75% of the voting member groups are required to vote in favor.
International standard ISO7326 was formulated by the 1SC>/TC45 Rubber and Rubber Products Technical Committee. This second edition replaces and abolishes the first edition. (IS()?326:1984), with technical revisions by the First Emperor. INTRODUCTION
The method described in this standard provides an evaluation of the performance of a hose under static conditions with respect to the deterioration of atmospheric ozone. Chemical Industry Standard of the People's Republic of China
Rubber and plastics hoses
Evaluation of ozone resistance under static conditions
Rubber and plastics hoses-Assessment of ozone resistance under static conditionsHG /T2869—1997
idtIs07326:1991
Warning: Personnel using this standard should be familiar with regular laboratory operating procedures. This standard is not intended to cover all safety issues that may arise due to the use of this standard. It is the user's responsibility to develop appropriate safety and health systems and ensure compliance with national regulations. 1 Scope
This standard specifies two methods for determining the oxygen resistance performance of the outer coating of the hose. Method 1: Applicable to pipes with an inner diameter of less than 25mm (including 25mm), and use the hose itself to conduct the test; Method 2: Applicable to hoses with an inner diameter of less than 25mm, use a sample cut from the hose to conduct the test; Method 3: Applicable to hoses with an inner diameter greater than 25mm. Methods 1 and 2 are usually used for testing with samples taken from the outer covering 1 of the hose. When the test cannot be carried out according to method 2, method 3 is used. Even though the hose cover material tested is the same and the degree of vulcanization is the same, the results of the escape test according to Method 1 may differ from the results obtained by testing according to Methods 2 and 3. The test method used should be in accordance with the product standard. Note: For soft materials with buried pipe joints that cannot be sampled, their ozone resistance can be tested according to GR/T7762 using samples made of corresponding polymer ingredients with the same degree of vulcanization. 2 Referenced standards
The provisions contained in the following standards constitute provisions of this standard by being quoted in this standard. At the time of publication of this standard, the versions indicated were valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest edition of the following standards. GB2491-1991 Standard temperature, humidity and time for environmental conditioning and testing of rubber specimens (cqVIS() 471:1983 and IS0 1826:1981)
GB/T7762-1987 Static tensile test method for oxygen aging resistance of vulcanized rubber (1eyIS) 1431-1:1989) GB9865--1988 Preparation of vulcanized rubber samples and specimens (neqIS) 4661-1:1986) 3 test device
3.1 The ozone chamber should comply with the requirements of GB/T7762 with ammonia generation and devices for monitoring and controlling ozone concentration. 3.2 The sample fixture is used in method 1. As shown in Figure 1. The Ministry of Chemical Industry of the People's Republic of China approved the implementation on 1997-10-01 on 1997-04-21
Aluminum tube
HG/T 2869—1997
Blue base plate
Figure 1 Hose installation device for method 1 Www.bzxZ.net
All samples are two long
3.3 Sample fixture. Used for method 2, as shown in Figure 2, such as Sichuan paint or aluminum powder spraying become. Air measurement inverse quotient
Hose reinforcement layer
The length of the strip sample is 15 mm
Picture 2 Sample installation fixture for method 2
Outer surface of the hose | | tt | All devices placed in the test chamber should be made of materials that do not absorb or decompose ozone. 4 Sample
4.1 Sample type
4. 1. 1 Method 1
The sample is a hose sample, and its length is calculated according to formula (1): L -(r +d)+2a.
The length of the specimen in the formula;
The bending radius of the tested hose shall be in accordance with the provisions of 7.1.1; dThe outer diameter of the tested hose.
4.1.2 Method 2
HG/T2869-1997
The sample should be a strip sample cut along the axial direction of the hose, with a length of 150 mm and a width of 25mmml4 .1.3 Method 3
The sample shall be a strip sample of the outer coating of the hose with a width of 25 mm cut along the axial direction of the hose. According to the provisions of 4.8 in GB9865-1988, remove the imprint of the reinforcement layer and comply with the provisions of 4.2.1 in GB/T7762-1987. 4.2 Number of specimens
should be tested using two specimens.
5 Sample adjustment
Testing should not be carried out within 24 hours after the product is made. When selecting lines for comparative evaluation, the tests should be conducted at the same time intervals after manufacturing as much as possible. The time interval between sample preparation and testing shall comply with the provisions of GB2941.
Specimens installed according to the corresponding procedures should be placed in a dark or soft light place, at standard temperature (see GB2941), and adjusted in a basically odorless atmosphere 48
6 Test conditions| |tt||Unless otherwise specified in the relevant hose product standards, the sample should be placed in an oxygenation box with an ozone concentration of (50 ± 5) parts per billion (×10-) by volume, at (40 ± 2 ) C temperature exposure (72) h Note: It has been found that when the sample is exposed to a constant ozone concentration expressed in parts per billion by volume, differences in atmospheric energy will have an impact on ozone cracking. The ozone content in hydrogenated air can be considered by converting it into partial pressure (expressed in mPa) and compared with the constant ozone partial pressure to analyze this effect: Under standard atmospheric pressure and temperature conditions (101kPa, 273k), The ozone concentration of 1 text 10\ is equivalent to 1.01 mPs partial pressure. 7 Procedure
7.1 Method 1
7.1.1 Each sample is installed on the sample fixture as shown in Figure 1 ( 3.2). The radius r shall be equal to the minimum bend radius specified for the hose being tested: if not specified, it shall be six times the inner diameter of the hose. 7.1.2 Seal both ends of the specimen with anti-fouling caps to prevent softness. The inner lining and reinforcement layer of the pipe absorb ozone. 7.1.3 After placing the sample in an ozone environment for 2h, 1b, 24h, 48h and 72h, use a twice magnifying glass to inspect the sample while maintaining the tensile state, close to both sides of the sample. The position of the end fixation point is ignored. If cracks are found, record the color crack characteristics and the time when the cracks were first discovered. 7.2 Method 2
7.2.1 Install each sample as shown in Figure 2. onto the specimen clamps (3.3) so that the required length of the outer covering of the hose is achieved at a distance of 20 mm. Unless otherwise specified, the elongation of the outer layer is 20% at the edge of each specimen. and the inner lining should be coated with anti-oxygen varnish
7.2. 2 Place the sample in an ozone environment for 2 h, 4 h, 24 h, 48 h and 72 h, and use a twice magnifying glass to Inspect the sample while maintaining the tension, and ignore the areas close to the fixed points at both ends of the sample. If color cracks are found, record the crack characteristics and the time when the cracks were first discovered. 7.3 Method 3
7.3. 1 Mount each specimen to the specimen fixture (3.4).Make its elongation 20%. 7.3.2 After placing the sample in the ozone environment for 2h, 4h, 24h, 48h and 72h, use a double magnifying glass to check the sample while maintaining the tension state. The places near the fixed points at both ends of the sample are ignored. If cracks are found, record the crack characteristics and the time when the cracks were first found. 8 Test report
The test report should include the following:
a) This standard number:
b) Detailed description of the hose tested;
c) The test method used (1, 2 or 3); HG/T28691997
d) Specific description of the test conditions. For example, ozone concentration, temperature, exposure time and elongation e) Whether color cracks appear, if so, record its characteristics and the time when the cracks were first found; f) Test duration.
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