HG/T 2295-1992 Thermally conductive rubber gasket for color television
Some standard content:
Chemical Industry Standard of the People's Republic of China
Thermal Conductive Rubber Gaskets for Color Televisions
1 Subject Content and Scope of Application
HG 2295--92
This standard specifies the specifications and markings, technical requirements, test methods, inspection rules and markings, packaging, transportation and storage of thermally conductive rubber gaskets for high-power tubes of color televisions.
This standard applies to thermally conductive rubber gaskets for high-power tubes of color televisions, and is also applicable to rubber products for other similar occasions. 2 Referenced Standards
Determination of Tensile Properties of Vulcanized Rubber
Test Method for Rubber Shore A Hardness
GB1692
GB1695
GB2828
GB 5721
GB5722
GB6031
GB6032
GB7529
HG2296
Determination method of insulation resistivity of vulcanized rubberDetermination method of power frequency breakdown dielectric strength and withstand voltage of vulcanized rubberCount sampling procedure and sampling table for batch inspection (applicable to inspection of continuous batches)General provisions for marking, packaging and transportation of rubber sealing productsGeneral provisions for storage of rubber sealing products
Determination of international hardness of vulcanized rubber (30~85IRHD)Conventional test methodDetermination of international hardness of vulcanized rubber (30~85IRHD)Micro test methodGeneral provisions for appearance quality of molded and extruded rubber productsRubber wedges for color televisions
3 Specifications and markings
3.1 Specifications and dimensions: The specifications and dimensions of thermally conductive rubber gaskets are shown in the figure. 42±0.5
2—-±3. 1±8:2
Thickness0.25±0.05
Thermal conductive rubber gasket diagram
Approved by the Ministry of Chemical Industry of the People's Republic of China on June 1, 19922-0+ss
2—,5二.5
0午62
Implementation on October 1, 1993
HG 2295--92
3.2 Marking: Use letters and numbers to mark the product, namely "product name, specification, manufacturing unit, standard number". 42 × 29 × 0. 25
HG2295
Standard No.
Manufacturing Unit Code
Length × Width × Thickness, mm
Heat-conducting rubber gasket for high-power tube of color TV 4 Technical requirements
The material, raw materials and manufacturing process of heat-conducting rubber gasket for high-power tube of color TV shall meet the requirements of relevant technical specifications. 4.1
4.2The physical properties of the material (vulcanized rubber) shall meet the requirements specified in the following table. Item
Hardness, Shore A (degrees) or IRHD
Tensile strength, MPa
Elongation at break, %
Volume resistivity, a·cm
Breakdown strength, MV/m
Flame retardant properties, grade
Thermal conductivity W/m·K
4.3The appearance quality of rubber gaskets shall comply with the relevant provisions of GB7529. 4.4The dimensional tolerance of rubber gaskets shall comply with the provisions of Article 3.1. 5Test method
5.1Test specimen
The test specimen shall be taken from the product. If it cannot be directly prepared from the product, the standard specimen can be prepared from the same batch of rubber materials used to manufacture the product, using the same vulcanization conditions as the product.
5.2 Physical properties
5.2.1 Hardness measurement shall be carried out in accordance with GB6031, GB6032 (arbitration method) or GB531. 5.2.2 Tensile strength and elongation at break shall be measured in accordance with GB528. 5.2.3 Volume resistivity shall be measured in accordance with GB1692. 5.2.4 Determination of breakdown strength shall be carried out in accordance with GB1695. 5.2.5 Determination of flame retardancy shall be carried out in accordance with Appendix A of HG2296. 5.2.6 Determination of thermal conductivity shall be carried out in accordance with Appendix A. 5.3 Appearance quality
Appearance quality inspection shall be carried out in accordance with GB7529 using the visual method and a measuring tool with an accuracy of 0.02mm. 5.4 Dimensional tolerance
Dimensional tolerance measurement shall be carried out using a measuring tool with an accuracy of 0.02mm. 6 Inspection rules
6.1 Factory inspection
HG2295—92
The factory inspection items are product appearance quality, size, hardness, tensile strength, elongation at break, volume resistivity and thermal conductivity of rubber materials. 6.1.1 The appearance quality of products shall be inspected piece by piece. If the inspection result is unqualified, it is allowed to be repaired once. If it is still unqualified, it will be judged as unqualified.
Product size and some physical properties shall be inspected by batch. 6.1.2.1 Rubber gaskets manufactured with the same formula and process method shall be a batch of no more than 10,000 pieces or the corresponding amount of rubber materials. 6.1.2.2 The size of each batch of rubber gaskets shall be inspected according to GB2828, using the general inspection level I and AQL value of 2.5. 6.1.2.3 Each batch of rubber gaskets or their rubber materials shall be inspected for five items: hardness, tensile strength, elongation at break, volume resistivity and thermal conductivity. If rubber gaskets are used for sampling inspection, when one item fails, double samples should be taken for re-inspection of the unqualified items. If it still fails, the batch of products is unqualified; if rubber samples are used for inspection, when one item fails, the rubber is allowed to be cultivated once, and then all five items are re-inspected. If there is still one item that fails, the batch of rubber is unqualified, and the products produced with this batch of rubber are unqualified. 6.2 Type inspection
6.2.1 When it meets the conditions of 6.6.1a~f of GB1.3 "Guidelines for Standardization Work and Regulations for the Preparation of Product Standards", the product quality should be fully assessed, that is, all technical requirements specified in the standard should be inspected. 6.2.2 During normal production, the breakdown strength and flame retardant properties of products or rubber should be inspected at least once a quarter. If one of the test results fails, it is allowed to be re-inspected once. If it still fails, the products of that period are unqualified. 7 Marking, packaging, transportation, storage
7.1 The marking, packaging and transportation of materials shall refer to GB5721. 7.2 The storage of materials shall refer to GB5722. 7.3 Under the conditions of 7.1 and 7.2, the performance of the product shall comply with the provisions of this standard within a storage period of no more than 3 years from the date of manufacture.
A1 Principle
HG 2295-92
Appendix A
Determination of thermal conductivity of thermally conductive rubber gasket materials for color television sets (supplement)
The thermal wire method in the non-steady heat conduction method is adopted. When an electric current is passed through the metal thermal wire sandwiched between two samples, the thermal wire becomes hot due to the Joule effect. The thermal conductivity is determined based on the dependence of the temperature change of the thermal wire on the thermal conductivity of the sample. The thermal conductivity value of the sample is determined by the temperature increment of the thermal wire. A2 Instrument
Thermal conductivity meter. TC-32 thermal conductivity meter or thermal conductivity meter with the same function. The instrument is composed of a host, a sample table, an electrical zero compensation device, a detector, a bracket, etc.
A3 Sample
A3.12 Specifications: length 50~200mm, width 50~100mm, thickness 10~50mm or diameter 50mm, thickness 6~20mm. A3.2 Quantity: 2 pieces.
A3.3 The appearance quality of the sample must be uniform, without pores, cracks, and concave-convex defects with a depth (height) not exceeding 0.2mm. A4 Test procedure (taking TC-32 as an example)
A4.1 Before the test, the sample should be kept at 23±2℃ for at least 16h. A4.2 Connect the external power supply and turn on the preheating switch to preheat for 30minA4.3 Calibrate the instrument with a standard silicone rubber sample. A4.3.1 Turn off the power switch, place two standard silicone rubber sheets on the sample table, install the thermal wire and thermocouple, and place the magnetic code on the test piece. A4.3.2 Start the switch and press the range switch. When the measurement indicator lights are all on, press the measurement switch, and after about 100 seconds, the measured value will be displayed on the display.
A4.3.3 When the displayed value is 0.192W/m·K, all switches can be reset and the standard sample can be removed. 1 When the displayed value is different from 0.192W/m·K, adjust the digital knob to make it equal to 0.192W/m·K, and then lock it A4.3.4
.
A4.4 Install the sample on the sample table, clamp the thermal wire in the middle of the two samples, make the two leads of the thermocouple form a 30° angle, place the code on the sample, and cover the lid.
A4.5 Turn on the power switch and the range switch. If the thermal conductivity range of the material is known, it can be selected according to Table A1 and the required range switch can be pressed; otherwise, any one of the four range switches can be pressed, and then the appropriate range switch can be selected according to the indicator light (up or down). When the indicator light is not on, it means that the range switch selection is appropriate. Table A1 Range switch (key number) and range (thermal conductivity) key
Range, W/m·K
0.010~0.040
0.037~0.160
0.150~0.670
0.580~2.600
A4.6 When the measurement indicator lights on the instrument panel are all on, press the measurement switch to measure. After about 100s, the number 262
will appear on the display. This value is the test result.
HG2295-92
A4.7 Reset each switch, replace the sample for the next test or turn off the main power supply to shut down. A5
Test results
Because this instrument is equipped with a test result processing mechanism and a digital display, the test results can be directly obtained, and the value is taken to three decimal places. The legal unit of thermal conductivity is W/m·K. The conversion with non-legal units is shown in Table A2. Table A2 Conversion of thermal conductivity units
Legal units
W/m·K
A6 Test report
Material name and number;
Specimen specifications;
Test temperature;bzxz.net
Test results and conditions;
Test date and tester and reviewer.
Additional notes:
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Northwest Rubber Industrial Products Research Institute of the Ministry of Chemical Industry. This standard was drafted by the Northwest Rubber Industry Products Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Su Guirong, Le Guiqiang and Han Shuyu. Non-legal unit
Kcal/m·h·C
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.