GB/T 14832-1993 Compatibility test of rubber materials and hydraulic fluids
Some standard content:
National Standard of the People's Republic of China
Test of compatibility between rubber material and hydraulic fluidGB/T 14832—93
This standard adopts ISO6072-—1986 "Hydraulic transmission—Compatibility test of elastomer materials and fluids". Subject content and scope of application
This standard specifies the compatibility index of vulcanized rubber and hydraulic fluid and its determination method. This standard is applicable to the evaluation of the influence of hydraulic fluid on nitrile rubber, fluororubber, and EPDM rubber; it is also applicable to the evaluation of the relationship between test rubber and industrial rubber; it is helpful to develop various new hydraulic fluids that are compatible with various elastomers. 2 Reference standards
GB/T528 Determination of tensile properties of vulcanized rubber and thermoplastic rubber GB/T531 Test method for Shore A hardness of vulcanized rubber Determination of density of vulcanized rubber
GB/T533
GB/T1232 Determination of Mooney viscosity of unvulcanized rubber GB/T 1690
Test method for liquid resistance of vulcanized rubber
Standard temperature, humidity and time for environmental conditioning and testing of rubber specimens GB2941
GB3777
Classification and naming of carbon black for rubber
8 Technical conditions for carbon black for rubber
GB 3778
GB5577
Regulations on synthetic rubber grades
: Determination of international hardness of vulcanized rubber (30~85IRHD) Micro test method GB/T6032
GB 6038
Rubber test compound compounding, mixing, vulcanization equipment and operating procedures Determination of constant deformation compression set of vulcanized rubber at room temperature and high temperature GB/T 7759
GB9865 Preparation of vulcanized rubber samples and test specimens HG/T2198 General requirements for physical test methods of vulcanized rubber 3 Terminology
3.1 Test elastomer
refers to a vulcanized rubber with a certain composition specified in this specification, which is used to evaluate the influence of hydraulic fluid on rubber. In order to keep the test error small, the vulcanized rubber contains only the most basic compounding ingredients. The test rubber specified in this standard is standard nitrile rubber (NBR-1), standard fluororubber (FPM-1), and standard ethylene terephthalate rubber (EPDM-1). The formula and production requirements are shown in Appendix A. 3.2 Commercial rubber refers to the rubber material actually used, which contains more compounding ingredients than standard rubber to meet the processing and use needs. Industrial rubber is not suitable for testing the quality of working media.
3.3 Compatibility index elastomer compatibility index (ECI) Approved by the State Administration of Technical Supervision on December 30, 1993, implemented on October 1, 1994
GB/T14832-93
The compatibility index of vulcanized rubber and hydraulic fluid specified in this standard refers to the volume change percentage (△V), hardness change (H), tensile strength change percentage (T) and elongation at break (AE) of vulcanized rubber after being immersed in the test liquid at a certain temperature for a certain period of time.
3.4 Volume change index volume change index (VCI) The volume change percentage is expressed as the nearest integer, see Appendix B. 4 Test specimens
4.1 Preparation of test specimens
The preparation of test specimens shall comply with the requirements of GB9865. 4.2 Specimen specifications
The specimen for measuring volume change is a square specimen with a thickness of 2±0.2mm, a length and width of 25.0±0.1mm respectively. The specimen for measuring hardness shall comply with the provisions of GB/T6032. The specimen for measuring tensile strength and elongation at break shall be a Type 2 specimen specified in GB/T528. 5 Test conditions
The test liquid, test temperature and time applicable to each type of rubber specified in this standard shall be as specified in Table 1. If test conditions different from those specified in this standard are required, they shall be noted in the test report. 6 Test methods and steps
Except for the specimen and the test liquid, the volume change, hardness change, tensile strength change and elongation at break of the specimen shall be carried out in accordance with the steps and requirements specified in Articles 4.1, 4.3 and 4.2 of GB/T1690 respectively. The hardness change shall be measured by the micro test method specified in GB/T6032; it can also be measured by a Shore A hardness tester, but the result needs to be noted. Table 1 Test conditions for determining the compatibility index of vulcanized rubber Test liquid
Mineral oil
Water-polyethylene glycol solution
Oil-water emulsion
Water-oil emulsion
Halogenated hydrocarbons
Phosphate esters
Test rubber
EPDM-1
FPM-12
Note: 1) The test is carried out for 168 h. Equilibrium swelling may not be achieved in these liquids. 2) FPM-1 is not suitable for alkyl phosphate esters. 16
Test liquid temperature
Test time
7 Expression of results
GB/T 14832-93
7.1 The percentage change in volume (△V) is calculated according to the formula specified in Article 5.1 of GB/T1690. 7.2 Hardness change (△H) is calculated according to the following formula. AH - H, - H.
Wherein: H. Hardness value of the specimen before immersion; Hi—hardness value of the specimen after immersion.
7.3 Percent change in tensile strength (△T), calculated in accordance with the provisions of Article 5.3 of GB/T1690. 7.4 Percent change in elongation at break (△E), calculated in accordance with the provisions of Article 5.3 of GB/T1690. 8 Test report
The test report shall include the following:
Type of test fluid (the proportion of the prepared solution shall be indicated); Rubber type;
Compatibility index of the test fluid and rubber material, if the rapid method in Appendix B is used for determination, the volume change index shall be reported; Appearance change of the specimen;
Discoloration and precipitation of the test fluid;
If the test temperature and time do not comply with the provisions of Table 1, the test temperature and time adopted shall be indicated; Test date;
Tester and auditor.
A1 Subject content and scope of application
GB/T 14832- 93
Appendix A
Preparation of standard rubber for testing
(Supplement)
This appendix specifies the formulation, mixing and vulcanization methods of standard nitrile rubber, fluororubber and EPDM rubber for testing. This appendix is applicable to the preparation of nitrile rubber, EPDM rubber, fluororubber for testing and the specimens for compatibility testing. A2 Raw materials
The raw materials used for the preparation of test rubber shall comply with the provisions of relevant national standards or technical conditions. A3 Preparation of test rubber
The formulation, mixing equipment and vulcanization equipment of the test rubber recommended in this appendix shall comply with the provisions of Articles 2.2, 2.3 and 3.2 of GB6038 respectively.
A3.1 Standard nitrile rubber (NBR-1)
A3.1.1 Formulation
The formulation of NBR-1 is listed in Table A1.
A3.1.2 Mixing
Maintain the roller surface temperature at 50±5℃ and mix according to the following procedure. Adjust the mixing mill to 1.4mm, wrap the raw rubber around the roller, and plasticize for about 2 minutes. a.bzxz.net
At a constant roller speed, add zinc oxide along the roller, and then add antioxidant RD for about 2 minutes. b.
Formula of standard nitrile rubber (NBR-1) in Table A1
Zinc oxide
Antiaging agent RD
Quick extrusion carbon black
Specifications or requirements
GB 5577, NBR 2707
Acrylonitrile content (28±1)%
Industrial first-class products
Softening point 70~85℃, heating loss ≤0.3%, ash content ≤0.2%
GB3778, N550, - and other products
Melting point ≥38.5℃, total volatile matter 0.25%, content ≥97%
Number of copies (by mass)
Make a 3/4 cut from one end to the other along the diagonal direction of the roller, about 1 minute. At a constant roller speed, add about half of the carbon black, and increase the roller distance from time to time to maintain a more stable accumulation of rubber, about 5 minutes. d.
Make 3/4 cuts three times from each side, about 2 minutes. Add the remaining carbon black and all the compounding agents that fell into the tray, about 5 minutes. Add DCP evenly,About 1min.
GB/T 14832-93
Make 3/4 cuts six times from each side for about 3min. Cut the rubber from the open mill, adjust the roller distance to 0.5mm, and continuously thin the rubber six times for about 2min. j. Discharge the film at a roller distance of 2.2mm, and place the film on a flat metal plate to cool. A3.1.3 Preparation of standard specimens
Prepare standard test pieces with a thickness of 2±0.2mm and specimens with a diameter of 13±0.5mm and a thickness of 6.3±0.3mm. The vulcanization conditions are all 170℃×20min.
A3.1.4 Control test
Before conducting the control test, the sample shall be environmentally conditioned according to the provisions of Articles 3.2 and 4.1 of GB/T2941. The contents and requirements of the control test are listed in Table A2. Table A2 Control tests of standard nitrile rubber
Hardness (micro), IRHD
Tensile strength (Type 2 dumbbell specimen), MPa
Elongation at break (Type 2 dumbbell specimen), %
Compression set (100℃×22h, Type B integral specimen, compression 25%), %Density, Mg/m
Resistance to liquid B (23℃×22h mass change), %A3.2 Standard fluororubber (FPM-1)
A3.2.1 Formulation
The formulation of FPM-1 is listed in Table A3.
1.23±0.01
Table A3 Formula of standard fluororubber (FPM-1)
Vinylidene fluoride-hexafluoropropylene copolymer
Magnesium oxide
Medium particle thermal cracking carbon black
No. 3 curing agent
Specifications or requirements
GB 5577, FPM 2601
GB 3778, N990
Melting point range 84~91.5℃, ignition residue <0.1%A3.2.2 Mixing
Maintain the roller surface temperature at 505℃ and mix according to the following procedure. a.
Test method
GB/T6032
GB/T528
GB/T528
GB/T 7759
GB/T533
GB/T1690
Number of copies (by mass)
Adjust the roller gap to 1.4mm to roll the raw rubber, about 3 minutes. Add carbon black, magnesium oxide, and No. 3 vulcanizer evenly into the roll gap at a constant roller speed, about 12 minutes. Adjust the roller gap from time to time to maintain a constant accumulation of rubber, about 3 minutes. When all the compounding agents are added (including the compounding agents that fall on the tray), make a 3/4 cut from each side, about 1 minute. Make three 3/4 cuts from each side, about 2 minutes. Remove the rubber from the open mill, adjust the roller distance to 0.5 mm, and continuously thin the rubber six times for about 3 minutes. 169
GB/T 14832—93
Adjust the roller distance to 2.2 mm to produce the sheet, and the sheet can be cooled on a flat metal plate for 24 hours. g.
After cooling for 24 hours, roll the mixed rubber six times at a roller distance of 0.8 mm and a roller surface temperature of 40±5°C. h.
i. Produce the sheet at a roller distance of 2.2 mm and place the sheet on a flat metal plate to cool. A3.2.3 Preparation of standard specimens
Prepare standard test pieces with a thickness of 2±0.2 mm and cylindrical specimens with a diameter of 13±0.5 mm and a height of 6.3±0.3 mm. The vulcanization conditions are all 170℃×20min, and then secondary vulcanization is carried out in an oven. The process is as follows: room temperature one hour-150℃—hour
\200℃, constant temperature at 200℃ for 20h.
A3.2.4 Control test
Before the control test, the sample is subjected to environmental conditioning control test according to the provisions of Articles 3.2 and 4.1 of GB/T2941. The contents and requirements are listed in Table A4. Table A4 Control test items of standard fluororubber (FPM-1)
Hardness (micro), IRHD
Tensile strength (Type 2 dumbbell-shaped specimen), MPaTear elongation (Type 2 fluorine-containing specimen), %
Compression set (150℃×22h, Type B integral specimen, compression rate 25%), %Maximum density, Mg/m
Liquid resistance D (mass change at 23℃×22h), %A3.3 Standard ethylene propylene diene monomer rubber (EPDM-1) A3.3.1 Formulation
The formulation of EPDM-1 is listed in Table A5.
1.92±0.02
Table A5 Formula of standard EPDM-1
EPDM
Quick extrusion carbon black
Zinc oxide
Anti-aging agent
A3.3.2 Mixing
Specifications or requirements
GB5577, EPDM3014, EPDM3024
GB3778, N550, first-class products
Industrial first-class products
Softening point 70~85℃, heating loss ≤0.3%, ash content ≤0.2% Melting point ≥38.5℃, total volatile matter ≤0.25, content ≥97% Keep the roller surface temperature at 50±5℃ and mix according to the following procedures. a.
Test method
GB/T 6032
GB/T528
GB/T 528
GB/T 7759
GB/T 533
GB/T 1690
Number of copies (by mass)
Adjust the roller distance to 1.4mm to roll the raw rubber, about 2 minutes. Mix the carbon black, zinc oxide and antioxidant RD together, and add them evenly between the rollers at a constant roller speed, about 10 minutes. Adjust the roller distance from time to time to maintain a constant accumulation of rubber, about 2 minutes. When all the compounding agents (including those that fell on the tray) have been added, perform a 3/4 cut from each side, about 1 minute. Add DCP evenly along the roller, about 3 minutes. GB/T14832—93
f. When the DCP is mixed, perform three 3/4 cuts for about 2 minutes. Remove the rubber from the open mill and adjust the roll distance to 0.5mm. Thin the rubber six times continuously for about 2 minutes. g.
Discharge the sheet at a roll distance of 2.2mm and place the sheet on a flat metal plate to cool. h.
A3.3.3 Preparation of standard test pieces
Prepare standard test pieces with a thickness of 20.2mm and cylindrical test pieces with a diameter of $13.0±0.5mm and a height of 6.3±0.3mm, respectively. The vulcanization conditions are all 170℃×20min. A3.3.4 Control test
Before conducting the control test, the sample shall be environmentally conditioned according to the provisions of Articles 3.2 and 4.1 of GB2941. The content and requirements of the control test are shown in Table A6. Table A6 Control test items of standard EPDM rubber
Hardness (micro), IRHD
Tensile strength (type 2 bell-shaped specimen), MPaElongation at break (type 2 dumbbell-shaped specimen).%
Compression set (150℃×22 h, type B integral specimen, compression rate 25%),%. Maximum
Density, Mg/m
Butanone (mass change at 23℃×22h), %
Intended use
1.08±0.01
Test method
GB/T6032
GB/T 528
GB/T 528
GB/T 7759
GB/T533
GB/T 1690
The compatibility index of test standard rubber in different types of hydraulic fluids (i.e. test fluid) can be used to measure the quality of each type of hydraulic fluid. At the same time, by comparing with the compatibility index of industrial rubber of the same rubber type in the same hydraulic fluid (i.e. test fluid), the relationship between the test standard rubber and the industrial rubber can be determined.
Appendix B
Rapid method for determining the effect of mineral oil on rubber by volume change index (VCI) (supplement)
B1 Subject content and scope of application
This appendix specifies a simple and rapid method for determining the effect of mineral oil on rubber by measuring the volume change index of standard nitrile rubber in mineral oil.
This method is applicable to the quality control of mineral oil. B2 Test rubber
The test rubber shall be the standard nitrile rubber specified in Appendix A of this standard (see A3.1). The control test of the test rubber shall be in accordance with Appendix A3.1.2 and A3.1.3 and meet the requirements of Table A2. B3 Measuring instrument
The measuring instrument is a taper gauge, see Figure B1.171
B4 Test specimen
GB/T 14832-- 93
Φ24±(.025
629: 4. 025
In the scale interval between 24 and 29, the scale interval is 0.1mm, and the scale interval is 0.1mm. The scale interval and the depth of the scale interval are 0.07mm.
Dimension/diameter is 1:30
Figure B1 The rod of the taper gauge
The test specimen should be a rubber ring made of NBR-1 with an inner diameter of 25±0.22mm and a cross-sectional diameter of 1.8±0.08mm.472
B5 Steps
GB/T 14832—93
B5.1 Put the rubber ring under test into the rod of the taper gauge until the gap between the inner surface of the rubber ring and the taper gauge is no longer observable, and record the inner diameter dl of the rubber ring, accurate to 0.025mm. B5.2 Soak the rubber ring in 50-55mL of mineral oil at 100℃ for 22h, take it out and wipe it clean, and measure the inner diameter dz of the rubber ring after soaking in mineral oil in the same way as B5.1, accurate to 0.025mm. B6 Calculation of linear expansion percentage (SD): sD=d=d× 100
Where: d-—Inner diameter of rubber ring before immersion,
d,—Inner diameter of rubber ring after immersion.
Volume change percentage (SV)
Volume change percentage (SV) can be converted from SD, see Table B1. Table B1
Conversion table of linear expansion (SD) and volume change percentage (SV)SD
·(B1)
B8 Attenuation of results
The results are expressed by volume change index (VCI). B9 Precision of results
B9.1 Repeatability
GB/T14832—93
Continued Table B1
Repeatability is calculated by 0.62×A or /0.238A, A is the average value. Note: ① The VCI of various oils is within the range of 1 to 35. ② Repeated test results obtained by the same operator should not be considered incorrect unless they exceed the allowable value. B9.2 Reproducibility
Reproducibility is calculated by 1.0×A or A, A is the average value. Note: ① The VCI of various oils is within the range of 1 to 35. SD|| tt||② Unless the test results provided by the two laboratories exceed the allowable value, they shall not be considered incorrect. 17t
Additional Notes:
GB/T14832-93
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Northwest Rubber Industry 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 Gao Jingru, Li Zongqi, Liu Yinwen, Wang Xuexin and Zhu Wei. 173
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