GB/T 5019-2002 Test methods for mica-based insulating materials

This standard specifies the test methods for bonded mica materials, products based on bonded mica materials and mica paper. This standard applies to insulating materials made of flaked mica or mica paper, with or without reinforcement materials, for use in electrical equipment, and also applies to mica paper. GB/T 5019-2002 Test methods for mica-based insulating materials GB/T5019-2002 standard download decompression password: www.bzxz.net

ICS29.035.50
National Standard of the People's Republic of China
GB/T5019—2002
Replaces GB/T5019--1985
Insulating materials based on micaMethod softest
(IEC 60371-2:1987,Specification for insulating materials based on mica mica-Part 2: Methodsoftest, MOD)
2002-05-21 Issued
People's Republic of China
General Administration of Quality Supervision, Inspection and Quarantine
2003-01-01 Implementation
GB/T5019-2002
Normative references
General requirements for testing
Preparation of test specimens of curable materials
Apparent density
Tensile strength and elongation at break
Flexural strength and flexural modulus of elasticity·
Folding·
Stiffness·
Anti-seepage and displacement
Elastic compression and plastic compression
Resin Fluidity and coagulation
Gel time
Electrical strength
Characteristics of the relationship between dielectric loss factor and temperature at frequencies of 48Hz to 62HzCharacteristics of the relationship between dielectric loss factor and voltage at frequencies of 48Hz to 62HzDetection of defects and conductive particles
Permeability
Heat resistance
Appendix A (informative appendix) Comparison of the chapter and article numbers of this standard with those of IEC60371-2:1987...Appendix B (informative appendix) Technical differences between this standard and IEC60371-2:1987 and their reasons 12
GB/T5019—2002
GB/T5019 is one of the national standards in the series of "Mica-based insulating materials". These series of standards are listed below: - GB/T5019 "Test methods for mica-based insulating materials"; - GB/T5020 "Definition and general requirements for mica-based insulating materials"; - GB/T5021 "Mica-based insulating materials commutator partitions and materials"; GB/T5022 Mica-based insulating materials Mica boards for electric heating equipment". This standard modifies and adopts IEC60371-2:1987 "Mica-based insulating materials specification part 2: test methods" (English version), including its amendment IEC60371-2-Amd1:1994. This standard is redrafted based on IEC60371-2:1987. Appendix A lists the comparison table of the chapter and article numbers of this standard and the chapter and article numbers of IEC60371-2:1987.
Taking into account my country's national conditions, this standard made some modifications when adopting IEC60371-2:1987. The relevant technical differences have been incorporated into the text and marked with a vertical single line in the margin of the clauses to which they refer. A list of these technical differences and their causes is given in Appendix B for reference. Amendment IEC60371-2-Amd1:1994 has been incorporated into the text and marked with a vertical double line in the margin of the clauses to which they refer.
This standard replaces GB/T5019-1985 "Test methods for electrical insulating mica products". The main changes of this standard compared with GB/T5019-1985 are as follows: in addition to "heating loss", "softness", "edge curvature", "layering rate", "plasticity", "volume resistivity", and "high temperature insulation resistance". (Chapter 4, Chapter 12, Chapter 13, Chapter 14, Chapter 15, Chapter 19, Chapter 20 of the 1985 edition); - Added "scope", "normative references", "area greater than 10cm", "commutator diaphragm thickness", "apparent density", "size of flake mica", "folding", "permeability". (See Chapter 1, Chapter 2, 5.3.2.3, Chapter 7, 8.7, Chapter 11, Chapter 21); Modified "density" and "bending strength and bending elastic modulus" (Chapter 2 and Chapter 6 of the 1985 edition; Chapter 6 and Chapter 10 of this edition).
Appendix A and Appendix B of this standard are both informative appendices. This standard is proposed by the China Electrical Equipment Industry Association. This standard is under the jurisdiction of the National Technical Committee for Standardization of Insulating Materials (CSBTS/TC51). Drafting unit of this standard: Guilin Electrical Science Research Institute. This The main drafters of the standard are Zhao Ying and Yan Xuemei. The previous versions of the standard replaced by this standard are: -GB/T5019—1985.
1 Scope
Insulating materials based on mica
Test methods
This standard specifies the test methods for bonded mica materials, products based on bonded mica materials and mica paper. GB/T5019—2002
This standard applies to insulating materials made of flaked mica or mica paper, with or without reinforcing materials, for use in relevant electrical equipment, and is applicable to mica paper.
2 Normative referenced documents
The clauses in the following documents become clauses of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this standard, however , parties that reach an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any undated referenced documents, the latest version shall apply to this standard. GB/T1033-1986 Test method for density and relative density of plastics (eqYISO/DIS1183:1984) GB/T1408.1-1999 Test method for electrical strength of solid insulating materials - Test at power frequency (eqvIEC60243-1:1988) GB/T1409-1988 Test method for relative dielectric constant and dielectric loss factor of solid insulating materials at power frequency and audio frequency high frequency (including meter wavelength) (eqvIEC60250:1969) GB/T9341-2000 Test method for bending properties of plastics (idtISO178:1993) GB/T11026.1—1989 Guidelines for determining the heat resistance of electrical insulating materials - General procedure for establishing aging test methods and evaluating test results (eqvIEC60216-1:1987) GB/T11026.2—2000
Guidelines for determining the heat resistance of electrical insulating materials - Part 2: Choice of test judgment criteria (idtIEC60216-2:1990)
GB/T11026.4—1999
Guidelines for determining the heat resistance of electrical insulating materials - Part 4: Aging oven - Single chamber oven (idtIEC60216-4-1:1990)
ISO67:1981 Muscovite blocks, sheets and flakes - Classification by size 3 General requirements for tests
Unless otherwise specified, the removed specimens shall be conditioned for 24 h at a temperature of 23°C ± 2°C and a relative humidity of 50% ± 5%. The test can be carried out at a temperature between 15°C and 35°C. In case of dispute, the test should be carried out at a temperature of 23°C ± 2°C and a relative humidity of 50% ± 5%. 4 Preparation of test specimens of curable materials
Prepare the test specimens as follows.
Method 1:
Remove loose particles and exposed burrs from sufficient material to provide the test specimen required for a specific test. Cut and stack the materials required to prepare the test specimens. For strip materials, use the half-laminate method, with adjacent layers perpendicular to each other to achieve the required thickness of the test specimen laminate. If required, trim the edges to obtain the required size. Unless otherwise specified, adjust the temperature of the press to 160°C ± 5°C. At 15°C to 35°C, place the test specimen laminate between two pieces with a thickness not exceeding 1.5mm polished steel plate. 1
GB/T5019-2002
Insert a locating block of the same thickness as the required specimen plate. Place the assembly of polished steel plate and specimen stack into the center of the preheated press. Immediately close the press and apply sufficient pressure to the locating block. Allow the specimen stack to cure for at least 30 minutes. Remove the specimen plate and post-cure it at the temperature and time given in the individual material specification or as recommended by the supplier. Method:
Remove loose particles and exposed burrs from sufficient material to provide the specimen plate required for the specific test. For full width and sheet material, cut and stack the material required to prepare the specimen plate. For strip material, there are two recommended methods for preparing the specimen stack: a) Cut the strip into pieces with a length equal to the length of the specimen stack and stack the pieces together in parallel and semi-overlapping. The overlapping edge of the next layer should be offset from the overlapping edge of the previous layer. It is recommended to fix the pieces with a hot bucket or soldering iron. Take a metal plate with the same length and width as the required sample stack and a thickness of 2mm to 3mm. Wrap the metal plate with tape b)
in a half-lap manner, with each layer winding in the same direction until the thickness meets the requirements. It is recommended that each layer be started separately during winding, and the overlapping edge of the next layer should be staggered with the overlapping edge of the previous layer. A liner anti-sticking material should be placed between the metal plate and the tape. Finally, two sample stacks of equal thickness are formed. The prepared sample stack with the structure shown in Figure 1 is placed in the press. The following pressing procedure (see Figure 2) is only an example, and other pressing procedures should be in accordance with the contract. Close the cold press and apply a pressure of 0.15MPa. At a pressure of 0.15MPa, heat the press to 70℃. - Reduce the pressure to zero and open the press for a short time (degassing). - Heat the press to 90℃ at a pressure of 0.15MPa. Reduce the pressure to zero and open the press for a short time (degassing). Heat the press to 110°C at a pressure of 0.15 MPa. - Reduce the pressure to zero and open the press briefly (degassing). - Heat the press to 160°C ± 5°C at a pressure of 0.15 MPa and maintain it until the resin begins to gel. This moment is visually controlled with a test rod. Once the resin begins to gel, increase the pressure to 3 MPa. - Cure for 60 min at 3 MPa and 160°C ± 5°C or at other specified temperatures. - Cool the specimen under pressure.
After pressing, post-cure the specimen according to the time and temperature specified in the individual material specifications or recommended by the supplier. 5 Thickness
5.1 Test equipment
Depending on the material being tested, the following types of equipment are available for measuring thickness: 5.1.1 Constant pressure thickness gauge, with a measuring plane diameter of 6 mm to 8 mm, a graduation of 0.01 mm, and a reading of 0.005 mm allowed. The pressure applied to the specimen is 0.1×(1±0.1)MPa. When calibrated with a calibration gauge, the measurement accuracy should be within 0.005mm. 5.1.2 An instrument that complies with the provisions of 5.1.1, but the pressure applied to the specimen is 0.7×(1±0.1)MPa. 5.1.3 An instrument that complies with the provisions of 5.1.1, but the pressure applied to the specimen is 7.0×(1±0.1)MPa. 5.1.4 A testing device that can produce a constant pressure of 30×(1±0.1)MPa and can be evenly distributed over the entire surface of the specimen. It consists of a press with parallel platens and a system that allows measurement to ±0.02mm. 5.2 Specimen
5.2.1 For materials supplied in the form of plates or sheets, the specimen is a whole plate or sheet. 5.2.2 For materials supplied in roll form, the test specimen shall be a narrow strip cut along the full width of the roll, with an area of ​​0.2 m. 5.2.3 For materials supplied in strip form, the test specimen shall be a narrow strip of 2 m in length. 5.2.4 For materials supplied in the form of commutator separators 2
5.2.4.1 For commutator separators with an area of ​​10 cm2 or less, the test specimen shall be 5 individual separators. 5.2.4.2 For commutator separators with an area greater than 10 cm2, the test specimen shall be determined in accordance with the method given in the individual material specifications: a) The test specimen shall be a single separator,
GB/T5019--2002
The test specimen shall be a stack of separators pressed to the specified size (separated by a separator layer if necessary), and the number of separators shall be specified by the purchaser.
5.2.4.3 For flat plates cut into shapes other than separators, the test specimen shall be a single flat plate. 5.3 Procedure
Thickness measurements shall be made in accordance with one of the following procedures:5.3.1 For materials other than commutator separators supplied in sheets (including narrow strips), coils, or strips, measure 10 points evenly on each specimen: for sheets, along two diagonals; for coils and strips (not at the edges), along the approximate midline of the long side of the specimen. The measuring instrument shall be as specified in 5.1.1, with a pressure of 0.1 MPa.
5.3.2 For commutator separators and sheets and strips used to make commutator separators, use one of the following procedures.5.3.2.1 For thin sheets: measure the thickness of each specimen in accordance with the method specified in 5.3.1, using an instrument with a pressure of 7.0 MPa as specified in 5.1.3.
5.3.2.2 For separators with an area of ​​10 cm or less: measure one point on each of the five separators using an instrument with a pressure of 7.0 MPa as specified in 5.1.3.
5.3.2.3 For partitions with an area greater than 10 cm2: Measure the thickness as described in a) or b) below, using the method specified in the individual material specifications. a) For partitions supplied as individual pieces, measure three points evenly on the specimen using an instrument with a pressure of 7.0 MPa as specified in 5.1.3. b) For partitions supplied in stacks pressed to specified dimensions, each specimen consisting of a stack, measure the thickness using an apparatus with a pressure of 30 MPa under the conditions specified in 5.1.4. Ensure that all partitions in the stack being tested are aligned during the measurement. Prior to each measurement, measure the press deformation using a steel block of known dimensions approximately equal to the dimensions of the specimen being tested. When obtaining the thickness of the individual specimens (d,), including the thickness of the insulating layer (d,), the correction value for the press deformation shall be added to or subtracted from the measured value.
For a stack of (n-1) insulating layers and n partitions, the total thickness (d) is calculated as follows: d = nd, + (n-1) d,
Where:
d - the value of the thickness of the layer consisting of n partitions and (n-1) insulating layers, in millimeters (mm); - the value of the number of partitions,
the value of the thickness of a partition, in millimeters (mm); - the value of the number of insulating layers;
- the value of the thickness of a insulating layer, in millimeters (mm). 5.4 Results
For packaged stacks of partitions, the value of nd is used as the thickness of the layer, and the number of partitions per stack is reported. For all other cases, the median value of the result is used as the thickness of the sample, and the maximum and minimum values ​​are reported. 6 Density
This test is carried out according to the immersion method in GB/T1033-1986. For curable materials, a specimen plate of suitable size and trimmed edges is used for each specimen. The plate shall be prepared in accordance with the provisions of Chapter 4. 7 Apparent density
The apparent density is calculated from the median value of the mass per unit area and the thickness as follows: d
GB/T5019—2002
Where:
d—the value of the apparent density, in grams per cubic centimeter (g/cm\); m.
—the value of the mass per unit area, in grams per square meter (g/m2); d. The value of the thickness, in millimeters (mm). 8 Composition
8.1 Specimen
The mass of the specimen is about 5g (for thin materials, take about 250cm). The number of specimens is 2. The specimen shall include the complete thickness of the material. 8.2 The mass per unit area of ​​the material in the "received" state Take out the specimen from the original packaging at a temperature of 23℃±2℃ and test it within 4h. Weigh the sample (m,) to an accuracy of 1 mg, and measure the sample area (A) to an accuracy of ±1%.
The mass per unit area of ​​the material in the "as received" state is calculated as follows: m
Wherein:
-The value of the mass per unit area of ​​the material in the "as received" state, in grams per square meter (g/m\); the value of the mass of the sample in the "as received" state, in grams (g); A-the value of the sample area, in square meters (m\). 8.3 Mass fraction of volatiles and mass per unit area of ​​dry material·(3)
Unless otherwise agreed upon by the supply and demand parties, 8.2 Weigh the sample (m,) and heat it at 150°C ± 3°C for 1h. Cool it to room temperature in a desiccator and weigh it (mz).
The mass fraction of volatiles is calculated as follows: Tv=ml=mzx100
Where:
The mass fraction of volatiles is expressed as a percentage (%); Ty
-The mass of the sample after drying, in grams (g). The mass per unit area of ​​the dry material is calculated as follows: Where:
m-The mass per unit area of ​​the dry material, in grams per square meter (g/m2). 8.4 Mass fraction of adhesive and mass of adhesive per unit area 8.4.1 Materials without reinforcement or with inorganic reinforcement (4)
Put the sample (mz) dried according to 8.3 in a muffle furnace and heat it at 500°C ± 25°C. Unless otherwise specified, the heating time is 2h. After cooling to room temperature in a desiccator, weigh (m3). The mass fraction of the adhesive is calculated as follows: Ch
Where:
mz-ma×100
cb——the numerical value of the mass fraction of the adhesive, expressed as a percentage (%); ms——the numerical value of the mass of the sample after ignition, in grams (g). Note: In case of dispute, heating should continue until the mass is constant. When the difference between two consecutive weighings is not greater than 0.1%, the mass is considered to be constant. 4
The mass of the adhesive per unit area is calculated as follows:Where:
mi =me-ma
——The numerical value of the mass of the adhesive per unit area, in grams per square meter (g/m). m
8.4.2 Organic reinforced materials (soluble adhesives) GB/T5019-2002
Put the dried sample (m2) according to 8.3 into a filter crucible of a Soxhlet extractor or fat extractor with a capacity of 500 cm. The extraction test apparatus is shown in Figure 3.
The solvent recommended by the supplier should be able to completely dissolve the adhesive but should not dissolve the reinforcement. Boil under reflux for 2 h, or for a longer time if it is necessary to completely dissolve the adhesive. Take the treated sample out of the filter crucible and dry it at 135℃±2℃ for 0.5 h. Then put it in a desiccator and cool it to room temperature and weigh it (m.). The mass fraction of the adhesive is calculated as follows: cb=m2m×100
Where:
The mass of the sample after extraction, in grams (g). The mass of adhesive per unit area is calculated as follows: m, m, m
Note: The normal extraction time is 2 hours. For thicker materials, the material can be carefully peeled off to facilitate solvent penetration. 8.4.3 Organically reinforced materials (insoluble adhesives) (8)
Use the mz value (see 8.3) and ms value (see 8.4.1) and the mass per unit area of ​​the reinforcing material provided by the supplier to calculate the mass fraction of the organic reinforcing material in the sample (ms), and calculate the mass fraction of the adhesive as follows: (m, + me) × 100
Where,
is the numerical value of the mass of the organic reinforcing material in the sample, in grams (g). The mass of adhesive per unit area is calculated as follows: m, = mz - (m + m)
8.4.4 Organic silicone adhesive materials (soluble adhesives) Determine the content of organic silicone adhesives in accordance with the contract. A feasible method is as follows. (10)
Put the sample dried according to 8.3 into a previously dried and weighed filter crucible and weigh the difference in mass. The mass difference is the mass of the sample (mz).
Put enough diethylamine (reagent grade) into the flask of the Soxhlet extractor to fill 1.5 times the height of the siphon. Extract the sample completely at a siphon rate of (6-10) times/h (at least 4 h for thin materials and longer for thick materials). Allow the apparatus to cool and then replace the diethylamine with acetone and extract for 1.5 h as before. Remove the filter crucible from the extractor and dry it on a surface in air for 10 min. Then heat it in an oven at 105°C ± 2°C for 30 min.
After cooling the filter crucible to room temperature in the desiccator, weigh it and subtract the mass of the filter crucible to obtain the mass of the extracted sample (mz). The mass fraction of adhesive is calculated as follows: Ch
The mass of adhesive per unit area is calculated as follows: mz-m×100
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GB/T5019-2002
8.4.5 Organic silicone adhesive without reinforcement material (insoluble adhesive) is carried out in accordance with 8.4.1. The manufacturer shall specify the mass fraction of organic matter in the organic silicone paint base. The mass fraction of adhesive is calculated as follows: Ch
Where:
2×100
The value of the mass fraction of organic matter in the organic silicone paint base is expressed as a percentage (%). The mass of adhesive per unit area is calculated as follows: mg=
8.5The mass of reinforcement material per unit area
The supplier shall specify the mass per unit area of ​​the reinforcement material used. The method for determining this property shall be as specified in the contract. In addition, one of the following procedures may be used and stated in the contract. a) For inorganic reinforced materials:
After completing the heating cycle according to 8.4.1, carefully separate the reinforcing material and weigh (m). The mass of the reinforcing material per unit area is calculated as follows: mm
Where:
m--the numerical value of the mass of the reinforcing material per unit area, in grams per square meter (g/m\) m--the numerical value of the mass of the inorganic reinforcing material in the sample, in grams (g). b) For organic reinforced materials (soluble adhesives): After completing the heating cycle according to 8.4.2, carefully separate the reinforcing material and weigh (m,). The mass of the reinforcing material per unit area is calculated as follows: m-
Where:
the numerical value of the mass of the organic reinforcing material in the sample, in grams (g). 8.6 Mass fraction of mica and mass of mica per unit area Based on the above test results, the mass fraction of mica and the mass of mica per unit area can be calculated. For materials without reinforcement or with organic reinforcement: Cm
ms×100
wherein:
is the value of the mass fraction of mica, expressed as a percentage (%); the value of the mass of mica per unit area, expressed in grams per square meter (g/m\). For inorganic reinforced materials:
Cmm/Am?
m =mt-mi-m.
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8.7 Size of flaked mica
8.7.1 Test specimen
GB/T5019—2002
The size of thin plate test specimen should be 300mm×300mm. Strip test specimens and special test conditions are specified by the individual material specifications. 8.7.2 Test method
To remove the adhesive, place the specimen in a pan or shallow trough and boil it in 15% caustic potash (KOH) solution until disintegration occurs. If the adhesive cannot be removed by the above method, any other suitable solvent or the specimen is heated in a muffle furnace until the adhesive is completely removed so that the flaked mica can be measured. Alternatively, the flaked mica can be removed mechanically, but the flaked mica should not be torn in the process.
After disintegration, wash the removed flaked mica several times with hot water or fresh solvent and then allow it to dry. Determine the size of the flaked mica using the template specified in ISO 67.
9 Tensile strength and elongation at break
9.1 Test equipment
A constant speed loading test machine or a constant speed moving test machine can be used. The test machine is preferably power driven and graduated to read 1% of the value required by the individual material specifications.
9.2 Test specimens
At least five specimens shall be taken. The length of the sample should be such that the distance between the two clamps of the test machine is 200mm. When testing full width and sheet materials, the sample width is 25mm, and 5 samples are cut along the longitudinal and transverse directions. If the sample contains textile reinforcement, any two samples cut from the same direction should not contain the same weaving thread in the length direction. Strip materials are sampled along their longitudinal direction and according to the supplied width, the widest width shall not exceed 25mm. 9.3 Procedure
Fix the specimen on the testing machine. The method of applying the load is: the time from the start of the load application to the instant when the load reaches the specified minimum tensile strength is 60s ± 10s. Continue to apply the load until the specimen breaks, and record the force and elongation at break or the force and elongation at break of each component of the reinforcement. If the specimen breaks in the chuck of the testing machine or at the chuck, the result is invalid and the test is repeated with another specimen. When it is necessary to determine the tensile strength at the joint, place the joint approximately in the middle of the two chucks. Note: For some materials, additional measures may be required to prevent the specimen from slipping at the chuck of the testing machine. 9.4 Results
Report the tensile strength and elongation in both directions (if required). The tensile strength is the median of the five breaking loads and is expressed in N/10mm width. The elongation is the median of the five measurements and is expressed as a percentage of the original length. Report the maximum and minimum values ​​at the same time. 10 Flexural Strength and Flexural Modulus
10.1 Test Specimens
When measuring flexural strength, take five specimens in a direction parallel to and perpendicular to one edge of the sample. The length of each specimen shall not be less than 20 times the thickness of the sample being tested, the width of the specimen shall be 10mm25mm, and the thickness shall be 4mm±0.2mm. When measuring flexural modulus, take two specimens in a direction parallel to and perpendicular to one edge of the sample. For curable materials, the specimens shall be cut from a specimen plate prepared in accordance with Chapter 4. 10.2 Procedure
The test shall be carried out in accordance with GB/T9341-2000. The property shall be measured at 23°C and 155°C or at the temperature specified in the individual material specifications. 10.3 Results
Report the flexural strength and flexural modulus in two directions separately. The flexural strength shall be the median of five measurements, and the flexural modulus shall be the average of two measurements.
GB/T5019—2002
11 Folding
After the sample is kept at 23℃±2℃ for 1h, test it at this temperature. Fold any sample of suitable size 180° with the glass cloth facing inward. Fold it as quickly as possible with the thumb and index finger. Check whether the sample is broken or delaminated.
12 Stiffness
12.1 Conditioning and test environment
The sample should be balanced at the standard test room temperature of 23℃±2℃. 12.2 Samples
Full-width materials: Take 5 samples in each of the longitudinal and transverse directions, with a length of 200mm and a width of 15mm. Strip materials: Take 5 samples with a length of 200mm. For strips with a width greater than 10mm, the width is the bandwidth. When testing in the transverse direction, the bandwidth is the length of the sample.
12.3 Procedure
Measure the dimensions of the specimen to an accuracy of ±0.5 mm. Place the specimen as shown in Figures 4 and 5, symmetrically on the support table, with the long side of the specimen parallel to the groove and the glass cloth side of the specimen facing downward. Drive the pressure beam into the groove, encountering resistance from the specimen until the maximum resistance is reached. The rate at which the support table moves relative to the pressure beam should be such that the maximum force is reached within 15 s ± 3 s. A force measuring device such as a bench balance can be used to record the maximum resistance. The stiffness is calculated as follows:
Where:
S is the value of the stiffness in Newtons per meter (N/m), F
Fx is the value of the maximum bending load in Newtons (N); and the value of the specimen length in meters (m). 12.4 Results
Report the median, maximum, and minimum values ​​of the longitudinal (weft deformation) and transverse (warp deformation) stiffness, respectively, and indicate the test temperature. 13 Resistance to exudation and displacement
This test is usually used for commutator diaphragm materials. It is to determine the displacement of mica or adhesive (exudation), or the displacement of mica and adhesive under specific temperature and pressure conditions. This test is very artificial, so special attention should be paid when interpreting the test results. 13.1 Test equipment
A press capable of applying 60 MPa pressure to the specimen is used. Several 2 mm thick flat steel plates and a 10 mm thick steel block with a thermocouple hole drilled in it for temperature measurement.
13.2 Test specimens
The height of the test specimen is 12 mm15 mm and consists of several small mica plates with an area of ​​about 20 cm2 (the recommended size of the small mica plates is 40 mm×40 mm). Care should be taken in preparing the samples to ensure reproducibility of the specimens. All four edges of the small mica plates should be cut cleanly. For the test, a stack is formed consisting of n small mica plates forming the specimens and (n + 1) steel plates of the same area. The small mica specimens and the steel plates are placed alternately. The drilled steel blocks are placed in the middle of the stack and aligned vertically as much as possible. 13.3 Procedure
The stack prepared in accordance with 13.2 is placed between the two plates of a press that has been preheated to a temperature 5°C to 10°C higher than that specified in the individual material specification. A pressure of 60 MPa is then applied to the stack and the stack is surrounded by thermal insulation. When the temperature indicated by the thermocouple (see 13.1) reaches the temperature specified in the individual material specification, maintain the temperature and pressure for 30 min, after which the edges of the specimens are carefully inspected. NOTE: For other times, temperatures and pressures, these test conditions may be specified in the contract. 13.4 Results
Record the following
Displacement of the material;
Exposure indicated by a drop of adhesive at the edge of a specimen. 14 Elastic and Plastic Compression
This test is for commutator diaphragm materials.
Elastic and plastic compression are determined by the change in thickness of the material being tested after the dimensions have stabilized under a pressure that varies cyclically from 7 MPa to 60 MPa (see 14.3). The test temperature is stated in the individual material specification. Elastic and plastic compression are expressed as a percentage of the thickness measured at 7 MPa. 14.1 Test Apparatus
The test apparatus is as specified in 13.1. A measuring device is added so that the height of the laminate being tested can be measured to within 0.02 mm. 14.2 Test Specimens
The test specimens are as specified in 13.2. The number of specimens is two laminates. 14.3 Procedure
The laminate prepared in accordance with 14.2 (see 13.2) is placed between the two plates of a press, a pressure of 7 MPa is applied at room temperature and its total height de is measured. The laminate is surrounded by insulating material. The plates are then heated to a temperature 5°C to 10°C above the temperature (tpe) specified in the individual material specifications. This temperature is maintained until the thermocouple (see 13.1) indicates the temperature specified in the individual material specifications. The total height di of the laminate is then measured.
The pressure on the laminate is then increased to 60 MPa over a period of about 10 min and maintained for 15 min. The total height d of the laminate is then measured. wwW.bzxz.Net
The pressure is then reduced to 7 MPa over a period of about 5 min and the total height di of the laminate is again measured. The cycle is repeated, but the maximum pressure is maintained for only 5 min. This cycle is repeated until the difference between two consecutive measurements of d, and dz stabilizes to within 0.02 mm, at which point the cycle is considered to be stable. The cycle values ​​d, and dz after stabilization are recorded as D and Dz. Finally, the stack is cooled to room temperature under a pressure of 7 MPa and the total stack height ds is measured. Considering the deformation of the test equipment and the intermediate steel plate, the height of the steel plate stack used in the test after stabilization according to the above cycle at a specified temperature at 7 MPa and 60 MPa pressure is recorded as d, and d, respectively, and the height measured at 7 MPa pressure and room temperature is recorded as de.
14.4 Results
Record the number of layers and heights constituting the sample. The elastic compression of the material under test is calculated by the following formula: ED-d--d) ×100
Wherein:
E--the value of elastic compression, expressed as a percentage (%); (23)
D,--the value of the total height of the stack after cyclic stabilization at a pressure of 7MPa at a specified temperature, in millimeters (mm); d,--the value of the height of the steel plate stack after cyclic stabilization at a pressure of 7MPa at a specified temperature, in millimeters (mm); D,--the value of the total height of the stack after cyclic stabilization at a pressure of 60MPa at a specified temperature, in millimeters (mm); d,--the value of the height of the steel plate stack at a pressure of 60MPa at a specified temperature, in millimeters (mm). The plastic compression of the material under test is calculated by the following formula: 91 Specimens
When measuring the bending strength, take five specimens in the direction parallel to and perpendicular to one edge of the sample. The length of each specimen should not be less than 20 times the thickness of the sample being tested. The width of the specimen is 10mm25mm and the thickness is 4mm±0.2mm. When measuring the bending elastic modulus, take two specimens in the direction parallel to and perpendicular to one edge of the sample. For curable materials, the specimens should be cut from a specimen plate prepared in accordance with Chapter 4. 10.2 Procedure
The test shall be carried out in accordance with GB/T9341-2000. The property shall be measured at 23C and 155C or at the temperature specified in the individual material specifications. 10.3 Results
Report the bending strength and bending elastic modulus in two directions respectively. The bending strength is the median of 5 measurements, and the bending elastic modulus is the average of two measurements.
GB/T5019—2002
11 Folding
After the sample is kept at 23℃±2℃ for 1h, test it at this temperature. Fold any sample of suitable size 180° with the glass cloth facing inward. Fold it as quickly as possible with the thumb and index finger. Check whether the sample is broken or delaminated.
12 Stiffness
12.1 Conditioning and test environment
The sample should be balanced at the standard test room temperature of 23℃±2℃. 12.2 Samples
Full-width materials: Take 5 samples in each of the longitudinal and transverse directions, with a length of 200mm and a width of 15mm. Strip materials: Take 5 samples with a length of 200mm. For strips with a width greater than 10mm, the width is the bandwidth. When testing in the transverse direction, the bandwidth is the length of the sample.
12.3 Procedure
Measure the dimensions of the specimen to an accuracy of ±0.5 mm. Place the specimen as shown in Figures 4 and 5, symmetrically on the support table, with the long side of the specimen parallel to the groove and the glass cloth side of the specimen facing downward. Drive the pressure beam into the groove, encountering resistance from the specimen until the maximum resistance is reached. The rate at which the support table moves relative to the pressure beam should be such that the maximum force is reached within 15 s ± 3 s. A force measuring device such as a bench balance can be used to record the maximum resistance. The stiffness is calculated as follows:
Where:
S is the value of the stiffness in Newtons per meter (N/m), F
Fx is the value of the maximum bending load in Newtons (N); and the value of the specimen length in meters (m). 12.4 Results
Report the median, maximum, and minimum values ​​of the longitudinal (weft deformation) and transverse (warp deformation) stiffness, respectively, and indicate the test temperature. 13 Resistance to exudation and displacement
This test is usually used for commutator diaphragm materials. It is to determine the displacement of mica or adhesive (exudation), or the displacement of mica and adhesive under specific temperature and pressure conditions. This test is very artificial, so special attention should be paid when interpreting the test results. 13.1 Test equipment
A press capable of applying 60 MPa pressure to the specimen is used. Several 2 mm thick flat steel plates and a 10 mm thick steel block with a thermocouple hole drilled in it for temperature measurement.
13.2 Test specimens
The height of the test specimen is 12 mm15 mm and consists of several small mica plates with an area of ​​about 20 cm2 (the recommended size of the small mica plates is 40 mm×40 mm). Care should be taken in preparing the samples to ensure reproducibility of the specimens. All four edges of the small mica plates should be cut cleanly. For the test, a stack is formed consisting of n small mica plates forming the specimens and (n + 1) steel plates of the same area. The small mica specimens and the steel plates are placed alternately. The drilled steel blocks are placed in the middle of the stack and aligned vertically as much as possible. 13.3 Procedure
The stack prepared in accordance with 13.2 is placed between the two plates of a press that has been preheated to a temperature 5°C to 10°C higher than that specified in the individual material specification. A pressure of 60 MPa is then applied to the stack and the stack is surrounded by thermal insulation. When the temperature indicated by the thermocouple (see 13.1) reaches the temperature specified in the individual material specification, maintain the temperature and pressure for 30 min, after which the edges of the specimens are carefully inspected. NOTE: For other times, temperatures and pressures, these test conditions may be specified in the contract. 13.4 Results
Record the following
Displacement of the material;
Exposure indicated by a drop of adhesive at the edge of a specimen. 14 Elastic and Plastic Compression
This test is for commutator diaphragm materials.
Elastic and plastic compression are determined by the change in thickness of the material being tested after the dimensions have stabilized under a pressure that varies cyclically from 7 MPa to 60 MPa (see 14.3). The test temperature is stated in the individual material specification. Elastic and plastic compression are expressed as a percentage of the thickness measured at 7 MPa. 14.1 Test Apparatus
The test apparatus is as specified in 13.1. A measuring device is added so that the height of the laminate being tested can be measured to within 0.02 mm. 14.2 Test Specimens
The test specimens are as specified in 13.2. The number of specimens is two laminates. 14.3 Procedure
The laminate prepared in accordance with 14.2 (see 13.2) is placed between the two plates of a press, a pressure of 7 MPa is applied at room temperature and its total height de is measured. The laminate is surrounded by insulating material. The plates are then heated to a temperature 5°C to 10°C above the temperature (tpe) specified in the individual material specifications. This temperature is maintained until the thermocouple (see 13.1) indicates the temperature specified in the individual material specifications. The total height di of the laminate is then measured.
The pressure on the laminate is then increased to 60 MPa over a period of about 10 min and maintained for 15 min. The total height d of the laminate is then measured.
The pressure is then reduced to 7 MPa over a period of about 5 min and the total height di of the laminate is again measured. The cycle is repeated, but the maximum pressure is maintained for only 5 min. This cycle is repeated until the difference between two consecutive measurements of d, and dz stabilizes to within 0.02 mm, at which point the cycle is considered to be stable. The cycle values ​​d, and dz after stabilization are recorded as D and Dz. Finally, the stack is cooled to room temperature under a pressure of 7 MPa and the total stack height ds is measured. Considering the deformation of the test equipment and the intermediate steel plate, the height of the steel plate stack used in the test after stabilization according to the above cycle at a specified temperature at 7 MPa and 60 MPa pressure is recorded as d, and d, respectively, and the height measured at 7 MPa pressure and room temperature is recorded as de.
14.4 Results
Record the number of layers and heights constituting the sample. The elastic compression of the material under test is calculated by the following formula: ED-d--d) ×100
Wherein:
E--the value of elastic compression, expressed as a percentage (%); (23)
D,--the value of the total height of the stack after cyclic stabilization at a pressure of 7MPa at a specified temperature, in millimeters (mm); d,--the value of the height of the steel plate stack after cyclic stabilization at a pressure of 7MPa at a specified temperature, in millimeters (mm); D,--the value of the total height of the stack after cyclic stabilization at a pressure of 60MPa at a specified temperature, in millimeters (mm); d,--the value of the height of the steel plate stack at a pressure of 60MPa at a specified temperature, in millimeters (mm). The plastic compression of the material under test is calculated by the following formula: 91 Specimens
When measuring the bending strength, take five specimens in the direction parallel to and perpendicular to one edge of the sample. The length of each specimen should not be less than 20 times the thickness of the sample being tested. The width of the specimen is 10mm25mm and the thickness is 4mm±0.2mm. When measuring the bending elastic modulus, take two specimens in the direction parallel to and perpendicular to one edge of the sample. For curable materials, the specimens should be cut from a specimen plate prepared in accordance with Chapter 4. 10.2 Procedure
The test shall be carried out in accordance with GB/T9341-2000. The property shall be measured at 23C and 155C or at the temperature specified in the individual material specifications. 10.3 Results
Report the bending strength and bending elastic modulus in two directions respectively. The bending strength is the median of 5 measurements, and the bending elastic modulus is the average of two measurements.
GB/T5019—2002
11 Folding
After the sample is kept at 23℃±2℃ for 1h, test it at this temperature. Fold any sample of suitable size 180° with the glass cloth facing inward. Fold it as quickly as possible with the thumb and index finger. Check whether the sample is broken or delaminated.
12 Stiffness
12.1 Conditioning and test environment
The sample should be balanced at the standard test room temperature of 23℃±2℃. 12.2 Samples
Full-width materials: Take 5 samples in each of the longitudinal and transverse directions, with a length of 200mm and a width of 15mm. Strip materials: Take 5 samples with a length of 200mm. For strips with a width greater than 10mm, the width is the bandwidth. When testing in the transverse direction, the bandwidth is the length of the sample.
12.3 Procedure
Measure the dimensions of the specimen to an accuracy of ±0.5 mm. Place the specimen as shown in Figures 4 and 5, symmetrically on the support table, with the long side of the specimen parallel to the groove and the glass cloth side of the specimen facing downward. Drive the pressure beam into the groove, encountering resistance from the specimen until the maximum resistance is reached. The rate at which the support table moves relative to the pressure beam should be such that the maximum force is reached within 15 s ± 3 s. A force measuring device such as a bench balance can be used to record the maximum resistance. The stiffness is calculated as follows:
Where:
S is the value of the stiffness in Newtons per meter (N/m), F
Fx is the value of the maximum bending load in Newtons (N); and the value of the specimen length in meters (m). 12.4 Results
Report the median, maximum, and minimum values ​​of the longitudinal (weft deformation) and transverse (warp deformation) stiffness, respectively, and indicate the test temperature. 13 Resistance to exudation and displacement
This test is usually used for commutator diaphragm materials. It is to determine the displacement of mica or adhesive (exudation), or the displacement of mica and adhesive under specific temperature and pressure conditions. This test is very artificial, so special attention should be paid when interpreting the test results. 13.1 Test equipment
A press capable of applying 60 MPa pressure to the specimen is used. Several 2 mm thick flat steel plates and a 10 mm thick steel block with a thermocouple hole drilled in it for temperature measurement.
13.2 Test specimens
The height of the test specimen is 12 mm15 mm and consists of several small mica plates with an area of ​​about 20 cm2 (the recommended size of the small mica plates is 40 mm×40 mm). Care should be taken in preparing the samples to ensure reproducibility of the specimens. All four edges of the small mica plates should be cut cleanly. For the test, a stack is formed consisting of n small mica plates forming the specimens and (n + 1) steel plates of the same area. The small mica specimens and the steel plates are placed alternately. The drilled steel blocks are placed in the middle of the stack and aligned vertically as much as possible. 13.3 Procedure
The stack prepared in accordance with 13.2 is placed between the two plates of a press that has been preheated to a temperature 5°C to 10°C higher than that specified in the individual material specification. A pressure of 60 MPa is then applied to the stack and the stack is surrounded by thermal insulation. When the temperature indicated by the thermocouple (see 13.1) reaches the temperature specified in the individual material specification, maintain the temperature and pressure for 30 min, after which the edges of the specimens are carefully inspected. NOTE: For other times, temperatures and pressures, these test conditions may be specified in the contract. 13.4 Results
Record the following
Displacement of the material;
Exposure indicated by a drop of adhesive at the edge of a specimen. 14 Elastic and Plastic Compression
This test is for commutator diaphragm materials.
Elastic and plastic compression are determined by the change in thickness of the material being tested after the dimensions have stabilized under a pressure that varies cyclically from 7 MPa to 60 MPa (see 14.3). The test temperature is stated in the individual material specification. Elastic and plastic compression are expressed as a percentage of the thickness measured at 7 MPa. 14.1 Test Apparatus
The test apparatus is as specified in 13.1. A measuring device is added so that the height of the laminate being tested can be measured to within 0.02 mm. 14.2 Test Specimens
The test specimens are as specified in 13.2. The number of specimens is two laminates. 14.3 Procedure
The laminate prepared in accordance with 14.2 (see 13.2) is placed between the two plates of a press, a pressure of 7 MPa is applied at room temperature and its total height de is measured. The laminate is surrounded by insulating material. The plates are then heated to a temperature 5°C to 10°C above the temperature (tpe) specified in the individual material specifications. This temperature is maintained until the thermocouple (see 13.1) indicates the temperature specified in the individual material specifications. The total height di of the laminate is then measured.
The pressure on the laminate is then increased to 60 MPa over a period of about 10 min and maintained for 15 min. The total height d of the laminate is then measured.
The pressure is then reduced to 7 MPa over a period of about 5 min and the total height di of the laminate is again measured. The cycle is repeated, but the maximum pressure is maintained for only 5 min. This cycle is repeated until the difference between two consecutive measurements of d, and dz stabilizes to within 0.02 mm, at which point the cycle is considered to be stable. The cycle values ​​d, and dz after stabilization are recorded as D and Dz. Finally, the stack is cooled to room temperature under a pressure of 7 MPa and the total stack height ds is measured. Considering the deformation of the test equipment and the intermediate steel plate, the height of the steel plate stack used in the test after stabilization according to the above cycle at a specified temperature at 7 MPa and 60 MPa pressure is recorded as d, and d, respectively, and the height measured at 7 MPa pressure and room temperature is recorded as de.
14.4 Results
Record the number of layers and heights constituting the sample. The elastic compression of the material under test is calculated by the following formula: ED-d--d) ×100
Wherein:
E--the value of elastic compression, expressed as a percentage (%); (23)
D,--the value of the total height of the stack after cyclic stabilization at a pressure of 7MPa at a specified temperature, in millimeters (mm); d,--the value of the height of the steel plate stack after cyclic stabilization at a pressure of 7MPa at a specified temperature, in millimeters (mm); D,--the value of the total height of the stack after cyclic stabilization at a pressure of 60MPa at a specified temperature, in millimeters (mm); d,--the value of the height of the steel plate stack at a pressure of 60MPa at a specified temperature, in millimeters (mm). The plastic compression of the material under test is calculated by the following formula: 92 Specimens
Full-width material: Take 5 specimens in each of the longitudinal and transverse directions, with a length of 200 mm and a width of 15 mm. Strip material: Take 5 specimens, with a length of 200 mm. For strips with a width greater than 10 mm, the width is the width of the strip. When testing in the transverse direction, the width of the strip is the length of the specimen.
12.3 Procedure
Measure the specimen dimensions to an accuracy of ±0.5 mm. Place the specimens as shown in Figures 4 and 5, symmetrically on the support table, with the long sides of the specimens parallel to the grooves and the glass cloth side of the specimens facing downwards. Drive the pressure beam into the groove, encountering resistance from the specimens until the maximum resistance is reached. The support table should move at a rate relative to the pressure beam that enables the maximum force to be reached within 15 s ± 3 s. A force measuring device such as a bench balance can be used to record the maximum resistance. Stiffness is calculated as follows:
Where:
S is the value of stiffness in Newtons per meter (N/m), F
Fx is the value of the maximum bending load in Newtons (N); and the value of the specimen length in meters (m). 12.4 Results
(22)
Report the median, maximum, and minimum values ​​of the longitudinal (weft deformation) and transverse (warp deformation) stiffness, respectively, and indicate the test temperature. 13 Resistance to exudation and displacement
This test is usually used for commutator diaphragm materials. It is to determine the displacement of mica or adhesive (exudation), or the displacement of both mica and adhesive under specific temperature and pressure conditions. This test has a large human factor, so special attention should be paid when interpreting the test results. 13.1 Test equipment
A press that can apply a pressure of 60 MPa to the specimen is used. Several 2 mm thick flat steel plates and a 10 mm thick steel block with a hole drilled in it for thermocouple measurement.
13.2 Test Specimens
The test specimens shall be 12 mm by 15 mm high and shall consist of several small mica plates with an area of ​​approximately 20 cm2 (the recommended size of the small mica plates is 40 mm × 40 mm). Care shall be taken in preparing the specimens to ensure reproducibility of the specimens and all four edges of the small mica plates shall be cleanly cut. For the purpose of the test, a stack shall be formed consisting of n small mica plates forming the test specimens and (n + 1) steel plates of the same area. The small mica plates and steel plates shall be placed alternately with the drilled steel block placed in the middle of the stack and aligned as vertically as possible. 13.3 Procedure
The stack prepared in accordance with 13.2 shall be placed between the two plates of a press which has been preheated to a temperature 5°C to 10°C above that specified in the individual material specifications. Then apply a pressure of 60 MPa to the stack and surround the stack with insulation. When the temperature indicated by the thermocouple (see 13.1) reaches the temperature specified in the individual material specification, maintain the temperature and pressure for 30 minutes, after which the edges of the specimens are carefully inspected. Note: For other times, temperatures and pressures, these test conditions may be specified in the contract. 13.4 Results
Record the following
Displacement of the material;
Exposure indicated by a drop of adhesive at the edge of the specimen. 14 Elastic compression and plastic compression
This test is used for commutator diaphragm materials.
Elastic compression and plastic compression are determined by the thickness change measured after the dimensions of the tested material have stabilized under the action of a pressure that varies cyclically from 7 MPa to 60 MPa (see 14.3). The test temperature is specified in the individual material specification. Elastic and plastic compressions are expressed as a percentage of the thickness measured at a pressure of 7 MPa. 14.1 Test Apparatus
The test apparatus is as specified in 13.1. A measuring device is added so that the height of the laminate to be tested can be measured to within 0.02 mm. 14.2 Test Specimens
The test specimens are as specified in 13.2. The number of test specimens is two laminates. 14.3 Procedure
Place the laminate prepared in accordance with 14.2 (see 13.2) between the two plates of the press, apply a pressure of 7 MPa at room temperature and measure its total height de. Surround the laminate with insulating material. Then heat the plates to a temperature 5°C to 10°C higher than the temperature (tpe) specified in the individual material specification. Maintain this temperature until the thermocouple (see 13.1) indicates the temperature specified in the individual material specification. Then measure the total height di of the laminate.
The pressure on the laminate is then increased to 60 MPa over a period of about 10 min and maintained for 15 min. Then measure the total height d. of the stack.
Reducing the pressure to 7 MPa in about 5 minutes, the total height di of the stack is measured again. The cycle is repeated, but the maximum pressure is maintained for only 5 minutes. Repeating this cycle until the difference between two consecutive measurements of d, and dz stabilizes within 0.02 mm, the cycle is considered to be stable. The stable cycle values ​​d, and dz are recorded as D and Dz. Finally, the stack is cooled to room temperature under a pressure of 7 MPa and the total height ds of the stack is measured. Taking into account the deformation of the test equipment and the intermediate steel plate, the heights of the steel plate stack used in the test at 7 MPa and 60 MPa pressures after stabilization at a specified temperature are recorded as d, and d, respectively, and the height measured at 7 MPa pressure and room temperature is recorded as de.
14.4 Results
Record the number of layers and heights constituting the sample. The elastic compression of the material under test is calculated by the following formula: ED-d--d) ×100
Wherein:
E--the value of elastic compression, expressed as a percentage (%); (23)
D,--the value of the total height of the stack after cyclic stabilization at a pressure of 7MPa at a specified temperature, in millimeters (mm); d,--the value of the height of the steel plate stack after cyclic stabilization at a pressure of 7MPa at a specified temperature, in millimeters (mm); D,--the value of the total height of the stack after cyclic stabilization at a pressure of 60MPa at a specified temperature, in millimeters (mm); d,--the value of the height of the steel plate stack at a pressure of 60MPa at a specified temperature, in millimeters (mm). The plastic compression of the material under test is calculated by the following formula: 92 Specimens
Full-width material: Take 5 specimens in each of the longitudinal and transverse directions, with a length of 200 mm and a width of 15 mm. Strip material: Take 5 specimens, with a length of 200 mm. For strips with a width greater than 10 mm, the width is the width of the strip. When testing in the transverse direction, the width of the strip is the length of the specimen.
12.3 Procedure
Measure the specimen dimensions to an accuracy of ±0.5 mm. Place the specimens as shown in Figures 4 and 5, symmetrically on the support table, with the long sides of the specimens parallel to the grooves and the glass cloth side of the specimens facing downwards. Drive the pressure beam into the groove, encountering resistance from the specimens until the maximum resistance is reached. The support table should move at a rate relative to the pressure beam that enables the maximum force to be reached within 15 s ± 3 s. A force measuring device such as a bench balance can be used to record the maximum resistance. Stiffness is calculated as follows:
Where:
S is the value of stiffness in Newtons per meter (N/m), F
Fx is the value of the maximum bending load in Newtons (N); and the value of the specimen length in meters (m). 12.4 Results
(22)
Report the median, maximum, and minimum values ​​of the longitudinal (weft deformation) and transverse (warp deformation) stiffness, respectively, and indicate the test temperature. 13 Resistance to exudation and displacement
This test is usually used for commutator diaphragm materials. It is to determine the displacement of mica or adhesive (exudation), or the displacement of both mica and adhesive under specific temperature and pressure conditions. This test has a large human factor, so special attention should be paid when interpreting the test results. 13.1 Test equipment
A press that can apply a pressure of 60 MPa to the specimen is used. Several 2 mm thick flat steel plates and a 10 mm thick steel block with a hole drilled in it for thermocouple measurement.
13.2 Test Specimens
The test specimens shall be 12 mm by 15 mm high and shall consist of several small mica plates with an area of ​​approximately 20 cm2 (the recommended size of the small mica plates is 40 mm × 40 mm). Care shall be taken in preparing the specimens to ensure reproducibility of the specimens and all four edges of the small mica plates shall be cleanly cut. For the purpose of the test, a stack shall be formed consisting of n small mica plates forming the test specimens and (n + 1) steel plates of the same area. The small mica plates and steel plates shall be placed alternately with the drilled steel block placed in the middle of the stack and aligned as vertically as possible. 13.3 Procedure
The stack prepared in accordance with 13.2 shall be placed between the two plates of a press which has been preheated to a temperature 5°C to 10°C above that specified in the individual material specifications. Then apply a pressure of 60 MPa to the stack and surround the stack with insulation. When the temperature indicated by the thermocouple (see 13.1) reaches the temperature specified in the individual material specification, maintain the temperature and pressure for 30 minutes, after which the edges of the specimens are carefully inspected. Note: For other times, temperatures and pressures, these test conditions may be specified in the contract. 13.4 Results
Record the following
Displacement of the material;
Exposure indicated by a drop of adhesive at the edge of the specimen. 14 Elastic compression and plastic compression
This test is used for commutator diaphragm materials.
Elastic compression and plastic compression are determined by the thickness change measured after the dimensions of the tested material have stabilized under the action of a pressure that varies cyclically from 7 MPa to 60 MPa (see 14.3). The test temperature is specified in the individual material specification. Elastic and plastic compressions are expressed as a percentage of the thickness measured at a pressure of 7 MPa. 14.1 Test Apparatus
The test apparatus is as specified in 13.1. A measuring device is added so that the height of the laminate to be tested can be measured to within 0.02 mm. 14.2 Test Specimens
The test specimens are as specified in 13.2. The number of test specimens is two laminates. 14.3 Procedure
Place the laminate prepared in accordance with 14.2 (see 13.2) between the two plates of the press, apply a pressure of 7 MPa at room temperature and measure its total height de. Surround the laminate with insulating material. Then heat the plates to a temperature 5°C to 10°C higher than the temperature (tpe) specified in the individual material specification. Maintain this temperature until the thermocouple (see 13.1) indicates the temperature specified in the individual material specification. Then measure the total height di of the laminate.
The pressure on the laminate is then increased to 60 MPa over a period of about 10 min and maintained for 15 min. Then measure the total height d. of the stack.
Reducing the pressure to 7 MPa in about 5 minutes, the total height di of the stack is measured again. The cycle is repeated, but the maximum pressure is maintained for only 5 minutes. Repeating this cycle until the difference between two consecutive measurements of d, and dz stabilizes within 0.02 mm, the cycle is considered to be stable. The stable cycle values ​​d, and dz are recorded as D and Dz. Finally, the stack is cooled to room temperature under a pressure of 7 MPa and the total height ds of the stack is measured. Taking into account the deformation of the test equipment and the intermediate steel plate, the heights of the steel plate stack used in the test at 7 MPa and 60 MPa pressures after stabilization at a specified temperature are recorded as d, and d, respectively, and the height measured at 7 MPa pressure and room temperature is recorded as de.
14.4 Results
Record the number of layers and heights constituting the sample. The elastic compression of the material under test is calculated by the following formula: ED-d--d) ×100
Wherein:
E--the value of elastic compression, expressed as a percentage (%); (23)
D,--the value of the total height of the stack af
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