Some standard content:
Record number: 2763-1999
HG 2949-1999
This standard adopts the American Society for Testing and Materials standard ASTMD178:1993 "Rubber Insulation Sheet" which is revised from the chemical industry standard HG2949--1989 "Electrical Insulation Rubber Sheet". The main technical differences between this standard and HG2949--1989 are: according to ASTMD178:1993 and the actual situation of domestic manufacturers, the hot air aging performance of the rubber sheet has been adjusted, and the contents of HG2949-1989 that have been proven to be in line with national conditions and consistent with ASTM standards have been retained. From the date of implementation, this standard will replace HG2949-1989. Appendix A of this standard is the appendix of the standard. This standard was proposed by the Technical Supervision Department of the former Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Rubber Miscellaneous Products Technical Committee of the National Rubber Standardization Committee. The main drafting unit of this standard: Beijing Rubber Products Design and Research Institute. The drafting unit of this standard is Tianjin Shuang'an Protective Equipment Co., Ltd. The main drafters of this standard are Song Baoqing and Li Mei. This standard was first issued as a national standard in 1989, and was adjusted to a mandatory chemical industry standard in 1998 and renumbered. 352
1 Scope
Chemical Industry Standard of the People's Republic of China
Electrical Insulating Rubber Sheet
Rubber insulating sheet
HG2949—1999
Replaces HG2949—1989
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of electrical insulating rubber sheets (hereinafter referred to as insulating rubber sheets).
This standard applies to insulating rubber sheets made of rubber as the main material and used as auxiliary safety equipment for electrical equipment. 2 Referenced Standards
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 version of the following standards. GB/T528—1992 Determination of tensile properties of vulcanized rubber and thermoplastic rubber GB/T531-1992 Test method for Shore A hardness of vulcanized rubber (neqISO7619:1986) GB/T1034—1986 Test method for water absorption of plastics (eqvISO62:1980) GB/T1690--1992 Test method for liquid resistance of vulcanized rubber (neqISO1817:1985) 9 Determination method for power frequency breakdown dielectric strength and withstand voltage of vulcanized rubber GB/T 1695--1989
GB/T3512-—1989
GB/T 7762-1987
HG/T 3322-—1981
Technical requirements
Specifications and dimensions (see Table 1).
Basic dimensions
Rubber hot air aging test method (neqISO188:1976) Vulcanized rubber ozone aging test Static tensile test method (neqISO1431-1:1980) Vulcanized rubber elongation permanent deformation determination method (modulus tester method) Table 1
Limit deviation
Note: The length of the insulating rubber sheet shall be agreed upon by the supplier and the buyer. 3.2 Physical and mechanical properties of the insulating rubber sheet (see Table 2). Approved by the State Bureau of Petroleum and Chemical Industry on April 20, 1999 Basic dimensions
1000,1200
Limit deviation
Implementation on April 1, 2000
Hardness (Shore A)/degree
Tensile strength/MPa
Elongation at break/%
Elongation at set point (150%) Permanent deformation/%
HG 2949--1999
After hot air aging (70℃×72h): Tensile strength reduction rate/% Water absorption (23℃ distilled water×24h)/%
3.3 Electrical properties of insulating rubber sheets (see Table 3). Table 3
Thickness/mm
Test voltage/(effective value) kV
Minimum breakdown voltage/(effective value) kV
Note: When using insulating rubber sheets, there should be a certain margin between the test voltage and the maximum operating voltage according to relevant regulations to ensure personal safety. The color of the insulating rubber sheets shall be determined by negotiation between the supply and demand parties. 3.4
Appearance quality of insulating rubber sheets (see Table 4). Table 4
Defect name
Bright scar or uneven
Spongy
Test method
The depth or height shall not exceed the limit deviation of the rubber sheet thickness. There shall be no more than two bright scars with an area less than 100mm2 in every 5m
There shall be no more than 5 bubbles with an area less than 100mm per square meter, and the distance between any two bubbles shall not be less than 40mm. The depth and length shall not exceed 1/10 of the thickness of the rubber sheet.
Not allowed.
Not allowed.
The determination of tensile properties shall be carried out in accordance with the provisions of GB/T528. 4.1
4.2 The determination of hardness shall be carried out in accordance with the provisions of GB/T531. 4.3 The determination of fixed elongation permanent deformation shall be carried out in accordance with the provisions of HG/T3322. The specimen shall be stretched by 150%, held for 15 minutes, and recovered for 5 minutes after being removed from the clamp.
4.4 Water absorption test shall be carried out in accordance with the provisions of GB/T1034. 4.5 Hot air aging test shall be carried out in accordance with the provisions of GB/T3512. 4.6 Specifications and dimensions shall be measured with a steel tape measure and a vernier caliper with an accuracy of 0.02mm. Thickness measurement shall be carried out at 5 points evenly selected at both ends of the rubber sheet; the thickness of the rubber sheet with patterns shall be measured from the top of the pattern. 354
HG2949--1999
4.7 The appearance quality of the rubber sheet shall be inspected by visual inspection and corresponding measuring tools. 4.8 Breakdown voltage test shall be carried out in accordance with the provisions of GB/r1695. The test method of continuous equalizing voltage rise shall be adopted, and the number of samples shall be 5. 4.9 Withstand voltage test
4.9.1 Test instrument
The basic requirements for the test instrument and circuit shall comply with the relevant provisions of GB/T1695. The electrode material can be a 3mm thick rectangular metal plate with smooth chamfered and rounded edges, a wet cloth or a 3mm thick conductive rubber sheet. 4.9.2 Test steps
4.9.2.1 The rubber sheet to be tested shall be laid flat in the middle of the test platform, with the upper and lower plates symmetrically centered. The sides of the plates shall be 150mm smaller than the rubber sheet to be tested, and shall overlap evenly without leaving any gaps. 4.9.2.2 Continuously and evenly increase the voltage on the sample to the specified voltage value, maintain for 1 minute, and observe whether there is any breakdown. If there is no breakdown, the rubber sheet has passed the voltage withstand test.
4.9.2.3 When the sample is tested in sections, the edges of the two sections shall overlap to avoid missing the test. 4.9.2.4 If there is any breakdown, the broken part shall be cut off and marked as scrapped; the part without breakdown shall be tested again until there is no breakdown, and the rubber sheet has passed the voltage withstand test. 5 Test rules
5.1 Batching and sampling
The insulating rubber sheet is a batch based on the monthly output. One roll is randomly selected from each batch of rubber sheets, and sufficient samples are taken from 300mm from the end to the inside for physical and mechanical properties and breakdown voltage tests. 5.2 Inspection classification
5.2.1 Factory inspection
Specification size, appearance quality, test voltage, physical and mechanical properties and breakdown voltage are inspection items. Specification size, appearance quality and test voltage should be inspected roll by roll, and physical and mechanical properties and breakdown voltage should be inspected batch by batch. 5.2.2 Type inspection
All technical requirements listed in this standard are type inspection items. 5.3 Judgment rules
If there is one unqualified item in the specification size of each roll or two unqualified items in the appearance quality of each roll, the roll is a defective product. If any other performance item does not meet the requirements, double samples should be taken for retest of the item. If it still does not meet the requirements, the batch of products is a defective product.
6 Marking, packaging, transportation and storage
6.1 Each insulating rubber sheet should be printed with clear and permanent markings on both ends, including: product name, manufacturer name, trademark, specifications, and implementation standard number.
6.2 The insulating rubber sheets should be rolled and tied tightly, placed in packaging bags or boxes, and accompanied by a product quality certificate, including: batch number, production date, inspector code, manufacturer name, and trademark. Each package generally does not exceed 60kg. 6.3 During transportation and storage, the insulating rubber sheets should be kept clean and must not come into contact with oils, acids, alkalis, or other substances that may damage their quality, and should be kept away from direct sunlight.
6.4 During storage, the insulating rubber sheets should be placed vertically, the temperature should be 15℃~~+40℃, the relative humidity should be 50%~~85%, and they should be 1m away from heat sources. 6.5 Under the conditions specified in this standard, the quality and performance of insulating rubber sheets shall comply with the provisions of this standard within a storage period of no more than one year from the date of manufacture. For insulating rubber sheets that have exceeded the storage period, their performance shall be tested and confirmed to meet the requirements of this standard before they can be used. bZxz.net
A1 Scope
HG 2949—1999
Appendix A
(Appendix to the standard)
Special electrical insulating rubber sheets
This appendix specifies the product classification, technical requirements, test methods and acceptance rules of special electrical insulating rubber sheets (hereinafter referred to as special insulating rubber sheets).
This appendix applies to special insulating rubber sheets made of rubber as the main material and used as auxiliary safety equipment for electrical equipment. A2 Product classification
Different types of special insulating rubber sheets should have one or more properties such as ozone resistance, flame retardancy, and oil resistance. TA type insulating rubber sheet: ozone resistance.
TB type insulating rubber sheet: flame retardancy.
TC type insulating rubber sheet: oil resistant.
A3 Technical requirements
Physical properties shall comply with the provisions of Table A1.
Hardness (Shore A)/degree
Tensile strength/MPa
Elongation at break/%
Fixed elongation (150%) Permanent deformation/%
Hot air aging (70℃×72h): Tensile strength reduction rate/%Water absorption rate/%
Ozone resistance (40℃×3h, ozone concentration is (50±5)pphm, using 20% elongation) Flame retardant performance
Oil resistance (No. 2 standard oil, 23℃×24h) Volume change rate/%A4 Test method
A4.1 The determination of ozone resistance shall be carried out in accordance with the provisions of GB/T7762. A4.2 The determination of flame retardancy shall be carried out in accordance with the provisions of ISO35821. Index
No visible cracks
12.7 mm, after 30 s
Note: 1) ISO3582:1978 "Laboratory evaluation of the transverse burning characteristics of small specimens of porous plastics and porous rubber materials under weak flames", please refer to the translation of the Shenyang Rubber Industry Products Research Institute of the Ministry of Chemical Industry. A4.3 The determination of oil resistance shall be carried out in accordance with the provisions of GB/T1690. A5 Inspection rules
When inspecting each batch of special insulating rubber sheets, if any of the following conditions occurs, double samples should be taken from the batch of products for retesting of unqualified items. If one or more samples are still unqualified after the retest, the batch of products shall be unqualified. A5.1TA type insulating rubber sheet does not meet the ozone resistance performance specified in Table A1; 356
HG2949-1999
TB type insulating rubber sheet does not meet the flame retardancy performance specified in Table A1; A5.2
A5.3TC type insulating rubber sheet does not meet the oil resistance performance specified in Table A1. The parts not specified in this appendix (specifications and dimensions, electrical properties, appearance quality, physical properties test methods, withstand voltage and breakdown voltage test methods, inspection rules, marking, packaging, transportation and storage, etc.) are equivalent to the provisions of the standard for ordinary insulating rubber sheets.
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